Machine Design & Shop Practice
Refresh Trivia # 1
JCSF ENGINEERING REVIEW CENTER
2nd Floor Santos-Causing Building, National Highway
Halang, City of Calamba, Laguna
MACHINE DESIGN AND SHOP PRACTICE
(Refreshers Trivia # 1)
Prepared by: Jose R. Francisco, PME
September 2012
INSTRUCTION: Select the correct answer for each of the following questions. Mark only one answer for each item by shading the box corresponding to the
letter of your choice on the answer sheet provided. STRICTLY NO ERASURES ALLOWED. Use pencil No. 1 only
1.
o
If the angular deformation of a solid shaft should not to exceed 1 in a length of 1.8 m and the allowable shearing stress is 83 MMa, what is the
6
diameter of the shaft? Assume that the shaft material has G = 77 x 10 kPa.
a) 222.34 mm
b) 234.22 mm
c) 23.42 cm
d) 24.22 cm
⎛ πD3ss ⎞
⎟L
32⎜
⎜ 16 ⎟
TL 32T L
⎝
⎠ = 2 ss L
Solution: θ =
=
=
JG πD 4G
DG
π D 4G
2.
E=
(
D=3
)
)
Where,
d) 3.28 inches
53.5 P
53.5(200 )
=3
= 2.28 inches
N
900
For Main Power Transmitting Shaft:
For Small, Short Shaft:
P=
D3 N
80
P=
For Line Shaft Carrying Pulleys:
P=
D3N
53.5
D3N
38
P = transmitted power, Hp
N = shaft rpm
D = shaft diameter, in inches
A round steel shaft rotates at 200 rpm and is subjected to a torque of 275 N-m and a bending moment of 415 N-m. Determine the equivalent twisting
moment.
a) 597.84 N-m
b) 456.42 N-m
c) 546.43 N-m
d) 497.85 N-m
Solution:
ME =
M2 + T2 =
(415)2 + (275)2
= 497.85 N ⋅ m
2
A vertical steel cylinder water tank is 30 m in diameter and 45 m high. The allowable stress of the steel plate is 1224 kg/cm . Without reinforcing angle
bars and rods, what is the thickness of the steel plate?
a) 55.15 mm
b) 51.55 mm
c) 65.15 mm
d) 61.55 mm
Solution:
Where,
6.
(
F
Stress
3163.27 kg / cm 2 (2.205 lb / kg )(2.54 cm / in )2
= A =
= 42 857142.86 psi = 43 x 106 psi
Strain δ
0.00105
L
A line shaft is to transmit 200 Hp at 900 rpm. Find the diameter of the shaft.
a) 2.18 inches
b) 2.28 inches
c) 3.18 inches
Note:
5.
2(83 000)(1.8)
= 222.34 mm
π ⎞
6
1 ⎜⎜
77
x
10
⎟⎟
⎝ 180o ⎠
o⎛
2
Solution:
4.
2 ss L
=
θG
What modulus of elasticity in tension is required to obtain a unit deformation of 0.00105 from a load producing a unit tensile stress of 3163.27 kg/cm ?
6
6
6
6
b) 43 x 10 psi
c) 45 x 10 psi
d) 46 x 10 psi
a) 40 x 10 psi
Solution:
3.
D=
t=
(
)
pD
441 297 N / m 2 (30 m )
=
= 0.05515 m = 55.15 mm
2 s t E j 2 1224 kg / cm 2 (9.8066 N / kg )(100 cm / m )2
(
)
p = maximum pressure inside the tank, Pa
(
)(
)
p = ρ g H = 1000 kg / m 3 9.8066 m / s 2 (45 m ) = 441 297 Pa
st = hoop stress of the tank, Pa
The root diameter of a double square thread is 0.55 inch. The screw has a pitch of 0.2 inch. Find the outside diameter and the number of threads per
inch.
a) 0.75 inch and 5 threads/inch b) 0.50 inch and 5 threads/inch c) 0.75 inch and 4 threads/inch
d) 0.50 inch and 4 threads/inch
1
Number of Threads per inch
1
1
Number of threads per inch = =
=5
Where, p = the pitch
p 0.2
Solution: For the number of threads per inch,
For the major diameter,
Where,
p=
⎛p⎞
D o = D i + 2h = D i + 2⎜ ⎟ = D i + p = 0.55 + 0.2 = 0.75 inch
⎝2⎠
h = height or depth of thread =
p
2
1
→ for square thread
Machine Design & Shop Practice
7.
Refresh Trivia # 1
A flat belt is 6 inches wide and 1/3 inch thick and transmits 15 Hp. The center distance is 8 ft. The driving pulley is 6 inches in diameter and rotates at 2
3
000 rpm such that the loose side of the belt is on top. The driven pulley is 18 inches in diameter. The belt material is 0.035 lb/in and the coefficient of
friction is 0.30. Determine the belt net tension.
a) 175.5 lb
b) 157.5 lb
c) 155.7 lb
d) 165.7 lb
Solution: F = F1 − F2 =
2 T 2 ⎛ 63 000 Hp ⎞ ⎛ 2 ⎞ ⎡ 63 000(15) ⎤
= ⎜
⎟ = ⎜ ⎟⎢
⎥ = 157.5 lb
D
D⎝
n
⎠ ⎝ 6 ⎠ ⎣ 2 000 ⎦
33 000 Hp 33 000(15)
⎛ 6⎞
=
= 157.56 lb
⎟(2 000) = 3141.59 fpm F = F1 − F2 =
12
Vm
3141.59
⎝ ⎠
Other Solution: Vm = π D n = π⎜
8.
A right-handed single-thread hardened-steel worm has a catalog rating of 2.25 kW at 650 rpm when meshed with a 48-tooth cast-steel gear. The axial
o
pitch of the worm is 25 mm, normal pressure angle is 14.5 , and the pitch diameter of the worm is 100 mm. The coefficient of friction is 0.085.
Determine the shafts center distance.
a) 241 mm
b) 142 mm
c) 412 mm
d) 124 mm
Solution:
Speed Ratio, SR =
Tanλ =
Tg
D g cos λ
Dg
ωw n w
=
=
=
=
ωg
ng
Tw D w sin λ D w tan λ
p
L
25
=
=
= 0.07958
πD w πD w π(100 )
→ λ = 4.55 o
⎛ Tg ⎞
⎛T ⎞
⎞ ⎛T
⎛
⎟ D tan λ = ⎜ g ⎟D w ⎜ p ⎟ = ⎜ g
⎜ πD ⎟ ⎜ T
⎜T ⎟ w
⎜T ⎟
w ⎠ ⎝ w
⎝
⎝ w⎠
⎝ w ⎠
D w + D g 100 + 381.97
Center Distance, C =
=
= 241 mm
2
2
Pitch diameter of the gear, D g = ⎜
9.
⎞⎛ p ⎞ ⎛ 48 ⎞⎛ 25 ⎞
⎟⎜ ⎟ = ⎜ ⎟⎜ ⎟ = 381.97 mm
⎟⎝ π ⎠ ⎝ 1 ⎠⎝ π ⎠
⎠
o
A 20 straight-tooth bevel pinion having 14 teeth and a diametral pitch of 6 teeth/inch drives a 42-tooth gear. The two shafts are at right angles and in
the same plane. Find the pitch angle of the pinion.
o
o
o
o
b) 20
c) 14.5
d) 20.5
a) 18.4
Solution: γ = tan
⎛ Tp
⎜ Tg
⎝
−1 ⎜
⎞
⎟ = tan −1 ⎛⎜ 14 ⎞⎟ = 18.4 o
⎟
⎝ 42 ⎠
⎠
10. A double-thread worm has a pitch diameter of 3 inches. The wheel has 20 teeth and a pitch diameter of 5 inches. Find the gear helix angle.
o
o
o
o
b) 9.46
c) 6.49
d) 6.94
a) 4.69
Solution:
⎡⎛ T
λ = tan −1 ⎢⎜⎜ w
⎢⎣⎝ Tg
⎞⎛ D g
⎟⎟⎜
⎜
⎠⎝ D w
⎞⎤
⎡
⎤
⎟⎥ = tan −1 ⎢ 2 ⎛⎜ 5 ⎞⎟⎥ = 9.46 o
⎟⎥
20
3
⎝
⎠
⎣
⎦
⎠⎦
o
11. A 36-tooth pinion turning at 300 rpm drives 120-tooth gear of 14.5 involute full depth pressure angle. Determine the rpm of the driven gear.
a) 60 rpm
b) 45 rpm
c) 75 rpm
d) 90 rpm
⎛ Tp ⎞
⎟ = (300)⎛⎜ 36 ⎞⎟ = 90 rpm
⎟
T
⎝ 120 ⎠
⎝ g⎠
Solution: n g = n p ⎜
⎜
12. If two parallel shafts are connected by cylinders in pure rolling contact and turning in the same direction, and having a speed ratio of 2.75, what is the
Center distance of the two shafts assuming that the diameter of the smaller cylinder is 22 cm?
a) 18.25 cm
b) 19.25 cm
c) 20.25 cm
d) 17.25 cm
Solution:
Diameter of the bigger cylinder, D 2 = SR (D 1 ) = 2.75(22 ) = 60.5 cm
Center distance, C =
D 2 − D1 60.5 − 22
=
= 19.25 cm
2
2
13. Two extension coil springs are hooked in series that support a single weight of 100 kg. The first spring is rated at 4 kN/m and the other spring is rated at
6 kN/m. Determine the total deflection of the springs.
a) 408.6 mm
b) 486.0 mm
c) 480.6 mm
d) 460.8 mm
Solution:
δ t = δ1 + δ2 =
⎛ k + k2 ⎞
⎡4 + 6⎤
F F
⎟⎟ = (100 kg )(9.8066 N / kg )⎢
+
= F⎜⎜ 1
⎥ = 408.6 mm
k1 k 2
⎣ 4(6) ⎦
⎝ k1k 2 ⎠
14. A double thread ACME screw driven by a motor at 400 rpm raises the attached load of 900 kg at a speed of 10 m/min. The screw has a pitch diameter
of 36 mm; the coefficient of friction on threads is 0.15. The friction torque on the thrust bearing of the motor is taken as 20 % of the total input.
Determine the lead angle.
o
o
o
o
b) 14.265
c) 15.462
d) 16.452
a) 12.465
V
10
=
= 0.025 m = 25 mm
n 400
−1 ⎛ L ⎞
−1 ⎛ 25 ⎞
o
For the lead angle, λ = tan ⎜
⎜ πD ⎟⎟ = tan ⎜⎝ 36π ⎟⎠ = 12.465
m ⎠
⎝
Solution: For the lead,
L=
15. A cylinder having an internal diameter if 508 mm and external diameter if 914.4 mm is subjected to an internal pressure of 69 MPa and an external
pressure of 14 MPa. Determine the hoop stress at the inner surface of the cylinder.
a) 90.11 MPa
b) 91.10 MPa
c) 911.0 MPa
d) 19.10 Mpa
2
Machine Design & Shop Practice
Solution:
s ti =
(
Refresh Trivia # 1
⎡
)
p i ro2 + ri2 − 2p o ro2
ro2 − ri2
(69 MPa )⎢⎛⎜ 914.4
⎣⎢⎝
=
2
2
2
2
⎛ 914.4
⎞
⎞ ⎤
⎞ ⎛ 508
mm ⎟ + ⎜
mm ⎟ ⎥ − 2(14 MPa )⎜
mm ⎟
⎝ 2
⎠
⎠ ⎝ 2
⎠ ⎥⎦
2
⎛ 914.4
⎞ ⎛ 508
⎞
mm ⎟ − ⎜
mm ⎟
⎜
⎝ 2
⎠ ⎝ 2
⎠
sti = 90.11 Mpa
sti = maximum tangential or hoop stress at the inside
ro = outside radius, mm
pi = internal pressure, Mpa
Note: For the maximum tangential or hoop stress at the outside,
2
ri = inside radius, mm
po = external pressure, Mpa
Where,
16. A flat belt is 6 inches wide and 1/3 inch thick and transmits 15 Hp. The center distance is 8 ft. The driving pulley is 6 inches in diameter and rotates at 2
3
000 rpm such that the loose side of the belt is on top. The driven pulley is 18 inches in diameter. The belt material is 0.035 lb/in and the coefficient of
friction is 0.30. Determine the belt net tension.
a) 175.5 lb
b) 157.5 lb
c) 155.7 lb
d) 165.7 lb
Solution:
F = F1 − F2 =
2 T 2 ⎛ 63 000 Hp ⎞ ⎛ 2 ⎞ ⎡ 63 000(15) ⎤
= ⎜
⎟ = ⎜ ⎟⎢
⎥ = 157.5 lb
D
D⎝
n
⎠ ⎝ 6 ⎠ ⎣ 2 000 ⎦
17. What is the polar section modulus of a solid shaft with a diameter of 101.6 mm?
3
4
3
b) 209.5 cm
c) 205.9 cm
a) 209.5 cm
J 2J π 3 π
=
=
D = (10.16 )3 = 205.9 cm 3
c D 16
16
Zj =
Solution:
4
d) 205.9 cm
18. The transmitted torque of a hollow shaft is 3400 N-m at a shearing stress of 55 MPa. If the outside diameter is 1.25 times that of the inside diameter,
what is the inside diameter, in mm?
a) 64.87
b) 46.87
c) 84.67
d) 74.64
ss =
Solution:
16T
(
π D 1− β
3
D=3
4
16 T
(
π ss 1 − β
4
)
where, β =
)
=3
Di
1
=
= 0.8
D o 1.25
16(3.4 )
[
π(55 000)1 − (0.8)
4
]
= 81.092 mm
Di =
Do
81.092
=
= 64.87 mm
1.25
1.25
19. What is the stress area of a 1-inch diameter bolt that has a TPI (Threads per inch) of 8?
2
2
2
b) 0.626 in
c) 0.443 in
a) 0.565 in
Solution: A = π [D − 0.9743p ]2 : → p = 1 :
s
TPI
4
2
d) 0.606 in
→ A s = 0.606 in 2
20. Determine the Poisson’s ratio of a material whose modulus of elasticity is 200 GPa and whose modulus of rigidity is 80 GPa.
a) 0.33
b) 0.25
c) 0.38
d) 0.22
Solution: G
=
E
2(1 + ν)
E = 200GPa,
∴ν = 0.25
G = 80GPa:
21. A steel has a BHN = 300. What is its approximate ultimate strength in ksi?
a) 300 ksi
b) 150 ksi
c) 75 ksi
d) 200 ksi
Solution: Su ≈ 0.5(BHN), ksi
22. What is the pitch of an American Standard Screw Threads with designation 12-28 UNF?
a) 0.083 inch
b) 0.0357 inch
c) 0.5 inch
d) 0.75 inch
1
1
1
=
= 0.0357 inch
Solution: p = =
n No. of threads per inch 28
23. A thrust washer has an inside diameter of 12.7 mm and an outside diameter of 76.2 mm. For an allowable bearing pressure of 90 psi, determine the
axial load that the washer can sustain.
a) 618.5 lb
b) 537.2 lb
c) 702.2 lb
d) 871.2 lb
(
)
2
2
π ⎡⎛ 76.2 ⎞
⎛π⎞ 2
⎛ 12.7 ⎞ ⎤
⎟ D o − D i2 = (90 ) ⎢⎜
⎟ −⎜
⎟ ⎥ = 618.5 lb
4 ⎢⎝ 25.4 ⎠
⎝4⎠
⎝ 25.4 ⎠ ⎥⎦
⎣
Solution: F = pA = p⎜
24. What is the number of threads per mm and the tensile stress area of a standard Metric screw Thread designated by M10 x 1.5?
2
2
2
2
c) 1.5 and 57.99mm
d) 1.75 and 57.99 mm
a) 0.555 and 57.99 mm b) 0.667 and 57.99 mm
Solution: n =
1
1
=
= 0.667 threads per mm
p 1.5
[
]2 = 57.99 mm 2
For Standard Metric Screw Threads, A t = 0.7854(D − 0.9383p ) = 0.7854 10 − 0.9383(2.5)
2
2
Where At = tensile stress Area, mm ; D = basic major diameter, mm; p = pitch, mm
Note:
o
M stands for standard metric screw threads; 10 stands for the basic major diameter, which is 10 mm; 1.5 stands for pitch that is 1.5 mm.
2
25. An air cylinder has a bore of 25 mm and is operated with shop air at a pressure of 6.327 kg/cm . Find the push force exerted by the piston rod, in N.
3
Machine Design & Shop Practice
Refresh Trivia # 1
a) 127.57
(
b) 70.42
)
c) 402.75
d) 304.57
⎛π⎞ 2
⎛π⎞
2
2
Solution: F = pA = p⎜ ⎟ D = 6.327 kg / cm (9.8066 N / kg )⎜ ⎟(2.5 cm ) = 304.57 N
⎝4⎠
⎝4⎠
26. A single plate clutch has an outside diameter of 250mm and a coefficient of friction of 0.3 between the surfaces. Using the uniform wear method, what
is its maximum power transmitting capacity at 1000 rpm if the lining pressure is not to exceed 0.4 MPa?
a) 38.1 kW
b) 27.9 kW
c) 29.7 kW
d) 31.8 kW
Solution:
⎡ (D + d) ⎤
T = Pf ⎢
⎥ N fs :
⎣ 4 ⎦
To maximize T, take
d
(D − d )
2
D
→ thus, d =
3
→ P = πp max
dT
=0
dd
Then P = 9583N; → T = 283411N − mm :
→ d = 144.34mm
→ Power =
T(n )
= 29.7 kW
9.549 x10 6
27. Calculate the resultant bending load on a shaft that carries a 200mm-diameter, 20º full depth pinion. The pinion transmits 10 kW at 1750 rpm.
a) 258.0 N
b) 685.0 N
c) 850.2 N
d) 580.2 N
⎡ 10
⎤
2⎢
x 9.549 x106 ⎥
2
T
1750
⎦:
Solution: Ft =
= ⎣
D
200
→ Ft = 546.7 N
→ Fr = Ft tan φ = 198.6 N :
→ FR = Ft2 + Fr2 = 580.2 N
o
28. A pulley 600 mm in diameter transmits 40 kW at 500 rpm. The arc of contact between the belt and pulley is 144 , the coefficient of friction between belt
and pulley is 0.35 and the safe working stress of the belt is 2.1 MPa. Determine the belt tensions ratio, neglecting the effect of centrifugal force.
a) 2.41
b) 2.14
c) 1.24
d) 4.12
⎛ π ⎞
F1
0.35 (144 )⎜
⎟
= e fθ = (e )
⎝ 180 ⎠ = 2.41
F2
Solution:
29. A roller chain and sprocket is to drive vertical centrifugal discharge bucket elevator. The pitch of chain connecting sprockets is 1.75”. The driving
sprocket is rotating at 120 rpm and has 11 teeth while the driven sprocket is rotating at 38 rpm. Determine the number of teeth of driven sprocket.
a) 33 teeth
b) 35 teeth
c) 30 teeth
d) 34 teeth
Solution:
⎛n ⎞
⎛ 120 ⎞
T2 = T1 ⎜⎜ 1 ⎟⎟ = (11)⎜
⎟ = 34.74 ≈ 35 teeth
⎝ 38 ⎠
⎝ n2 ⎠
30. A 20-tooth motor sprocket, running at 1200 rpm, drives a blower at a speed ratio of 4:1. Using the largest permissible chain size and the largest
permissible center distance of 80 pitches, what length of chain in pitches is required to connect the sprockets?
a) 200 pitches
b) 212 pitches
c) 216 pitches
d) 220 pitches
2
3
⎡ 900 ⎤
Solution: p
⎥ = 0.825in. : largest RC no. is RC 60
max = ⎢
⎣ n1 ⎦
(N − N t1 ) = 212.pitches
N t1 + N t 2
+ 2C p + t 2
2
40C p
2
Lc =
o
31. A 20 involute spur gear has a tooth whole depth of 16.95 mm, a tooth thickness of 13.2 mm, and a pitch of 3. Determine the circular pitch of the gear.
a) 26.6 mm
b) 16.6 mm
c) 25.6 mm
d) 24.6 mm
Solution:
Pc =
π π
= = 1.0472 inches = 26.6 mm
Pd 3
th
32. Which of the following is the 4 most commonly used metal in the world?
a) Zinc
b) Steel
c) Aluminum
d) Copper
33. These springs are made from one or more flat strips of brass, bronze, steel or other materials loaded as cantilevers or simple beam.
a) Torsion springs
b) Leaf springs
c) Garter springs
d) Drawbar springs
34. This refers to the space between adjacent coils when the spring is compressed to its operating length.
a) Coil clearance
b) Pitch
c) Lead
d) Deflection
35. This material is the most popular alloy spring steel for conditions involving higher stresses than can be used with the high-carbon steels and for use
where fatigue resistance and long endurance are needed; this is also good for shock and impact loads.
a) Chrome silicon
b) Chrome vanadium
c) hard-drawn wire
d) Oil-tempered wire
36. For an American Standard Screw Threads, what does 6-32 UNC designate?
a) Size 6, 32 threads per inch, coarse thread
b) 6 inches basic diameter, 32 threads per inch, coarse thread
c) Size 6, 32 threads per inch, fine thread
d) 32 inches basic diameter, 6 threads per inch, coarse thread
•
Note: 6 stands for the designated size, 32 stands for the number of threads per inch, UNC stands for Coarse threads
37. How do you call the process of producing the residual compressive stress of machine parts, which is performed by directing the a high velocity stream
of hardened balls or pellets at the surface to be treated.
a) Nitriding
b) Shot blasting
c) Peening
d) Tempering
38. It is a process that produces residual compressive stress on the machine part, which uses a series of hammer blows on the surface.
a) Nitriding
b) Shot blasting
c) Peening
d) Tempering
o
39. It is a surface-hardening process for alloy steels in which the material is heated to 950 F in a nitrogen atmosphere, typically ammonia gas, followed by
slow cooling.
a) Quenching
b) Nitriding
c) Shot blasting
d) Peening
40. Which of the following gases is typically used in nitriding process of surface hardening?
a) Nitrogen gas
b) Carbon dioxide
c) Ammonia gas
d) Hydrogen gas
41. Which of the following is the benefit in using nitriding as a surface-hardening process for alloy steels?
a) Improvement of endurance strength, 50 % or more
b) Improvement of endurance strength, less than 50 %
4
Machine Design & Shop Practice
Refresh Trivia # 1
c) Improvement of endurance strength, more than 50 %
d) 80 % improvement on the endurance strength
42. In estimating the actual endurance strength of steel parts, one of the factors to be considered is the material factor, which of the following is the
recommended material factor for cast steel?
a) 0.70
b) 0.80
c) 0.75
d) 1.0
43. How do you call the level of stress that the part will be permitted to see under operating conditions?
a) Yield stress
b) Endurance stress c) Design stress
d) Ultimate stress
44. Which of the following column formulas is applicable to cast iron columns?
a) Euler’s formula
b) J.B.Johnson’s formula
d) Secant formula
d) Straight line formula
o
Ans. D. Straight line formula. Cast iron columns are usually designed on the basis of
P
⎡L ⎤
= 9000 − 40 ⎢ e ⎥
A
⎣k ⎦
o
→ a Straight line formula
Where the slenderness ratio Le/k should not exceed 70.
45. Which of the following ferrous metals has the lowest carbon content?
a) Carbon steel
b) Wrought iron
c) Cast iron
d) SAE 4140
o
Wrought iron usually contains less than 0.04% C; steel usually has less than 2.5% C; cast iron has more than 1.7% C; SAE 4140 has
approximately 0.4% C.
46. If stiffness is the main criterion in selecting a material, which of the following is the most economical choice?
a) SAE 3130
b) SAE 1020
c) SAE 6150
d) AISI 301, ¼ hard stainless steel
o
Ans. B. SAE 1020- plain carbon steel. All of the above materials are steel with practically equal modulus of elasticity. The three other materials are
alloy steels that are relatively more expensive.
47. Which of the following materials can easily be machined?
a) AISI C1020
b) AISI C1112
c) AISI C1030
d) AISI C1010
o
Ans. b. C1112. This is a free-cutting steel with a higher sulfur content for ease in machining
48. This is a combination of mechanisms and other components that transforms, transmits, or uses energy, load, or motion for a specific purpose. How do
yopu call this?
a) Mechanism
b) Engine
c) Machine
d) Linkage
49. It is the capacity of a material to absorb energy when it is deformed elastically and then, upon unloading, to increase this energy. What is this capacity
of a material?
a) Resilience
b) Toughness
c) Rigidity
d) Ductility
50. What is the ability of the material to absorb energy up to fracture?
a) Toughness
b) Rigidity
c) Resilience
d) Stiffness
51. It is a failure prediction theory, which states that a part subjected to any combination of loads will fail (by yielding or fracturing) whenever the maximum
shear stress exceeds a critical value. How do you call this failure prediction theory?
a) Distortion-energy theory
b) Maximum-shear-stress theory
c) Internal friction theory
d) Modified Mohr theory
52. What is the difference between the maximum and minimum size limits of a part?
a) Allowance
b) Tolerance
c) Deviation
d) Basic size
53. A lubrication condition where non-conformal surfaces are completely separated by lubricant film and no asperities are in contact.
a) Elastohydrodynamic lubrication
b) Boundary lubrication
c) Hydrodynamic lubrication
d) Hydrostatic lubrication
54. In a lathe machine, how do you call the diameter of the largest workpiece that can be rotated in a chuck or between centers without hitting the bed?
a) Chuck diameter
b) Swing
c) Distance between centers
d) Spindle diameter
55. How do you call a statistical data used to identify the most likely failure modes?
a) Finite element analysis
b) Fault free analysis
c) Failure analysis
d) Random analysis
56. It is a type of coil spring where the helical coil is wrapped into a circle forming an annular ring. How do you call this spring?
a) Volute spring
b) Motor spring
c) Hair spring
d) Garter spring
57. Wood is an ______ material; that is, its mechanical properties are unique and independent in three mutually perpendicular directions—longitudinal,
radial, and tangential.
a) Isotopic
b) Anisotropic
c) Orthotropic
d) Any of these
58. The principal raw materials used in steelmaking are iron ore, coal, and __________.
a) Coke
b) Limestone
c) Slag
d) Flux
59. The steel part is heated to a temperature of 900–1150 degrees F in an atmosphere of ammonia gas and dissociated ammonia for an extended period
of time that depends on the case depth desired.
a) Nitriding
b) Carburizing
c) Case hardening
d) Cyaniding
60. The primary application of high-speed steels is to tools used for the working of metals __________.
c) that are too soft
d) at slow cutting speeds
a) that are too hard
b) at high cutting speeds
61. In gearing, this is the ratio of the arc of action to the circular pitch.
a) Speed ratio
b) Arc ratio
c) Contact ratio
d) Gear ratio
62. Flywheel arms are usually of elliptical cross-section, the strength of the arms should equal _________the strength of the shaft in torsion.
a) Three-fourths
b) One-half
c) Two-thirds
d) One-fourth
63. This alloy (nickel, iron, chromium, cobalt is a non-magnetic, corrosion resistant material suitable for sub-zero temperatures and temperatures up to
about 750 degrees F., provided that torsional stresses are kept below 75,000 pounds per square inch. It is precipitation-hardened to produce
hardnesses of 48 to 50 Rockwell C and is used in watch and instrument springs.
a) Elinvar
b) Monel
c) Inconel
d) Dynavar
Ans. Dynavar; source: Machinery’s handbook
64. To ensure an adequate factor of safety in the design of a shaft with standard keyway, the key width should be about:
a) One half of the shaft diameter b) One fourth of the shaft diameter
c) One eighth of the shaft diameter
d) One third of the shaft diameter
Note: One-fourth of shaft diameter, as a guide in key selection for both square and flat rectangular keys.
65. What is the property of matter that causes it to resist any change in its motion or state of rest?
a) Momentum
b) Kinetic Energy
c) Inertia
d) Section modulus
66. This is defined as the cutting time to reach a predetermined wear, called the tool wear criterion.
a) Wear duration
b) Cycle time
c) Tool life
d) Life cycle
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Machine Design & Shop Practice
Refresh Trivia # 1
67. Which of the following G-codes refers to rapid traverse in CNC machining?
a) G00
b) G01
c) G02
d) G03
68. An acronym in CNC machining which means access of the machine operator to insert machining instructions directly into the NC machine control
system via push buttons, pressure pads, knobs, or other arrangements.
a) FMS
b) FMC
c) CIM
d) MDI
Note: MDI = manual data input
69. The variable polarity plasma arc (VPPA) process was developed for welding metals that form an oxide skin, such as ___________.
a) Steel
b) Copper
c) Cast iron
d) Aluminum
70. Which of the following statements is NOT true?
a) The terms “polishing” and “buffing” are sometimes applied to similar classes of work in different plants.
b) Polishing is any operation performed with wheels having abrasive glued to the working surfaces
c) Buffing is done with wheels having the abrasive applied loosely
d) Polishing is not so harsh an operation as buffing, and it is commonly utilized to obtain very fine surfaces having a “grainless finish.”
Note: Polishing is harsher than buffing.
71. If the steel is strongly deoxidized by the addition of deoxidizing elements, no gas is evolved, and the steel is technically called _______because it lies
quietly in the molds.
a) Quenched
b) Annealed
c) Killed
d) Tempered
72. Stainless steels generally contain at least __ per cent chromium, with or without other elements.
a) 18
b) 16
c) 12
d) 10
73. What grades of stainless steels are nonmagnetic in the annealed condition, although some may become slightly magnetic after cold working?
a) Ferritic grades
b) Austenitic grades
c) Martensitic grades
d) Any of these
74. These steels (SAE Steels 1006, 1008, 1010, 1015) are the lowest carbon steels of the plain carbon type, and are selected where ________ is the
primary requisite of the user.
a) Strength
b) Cold formability c) Ductility
d) Durability
75. What process is used to produce residual compressive stress on the crankshaft?
a) Hardening
b) Shot blasting
c) Peening
d) Nitriding
76. Steel is heated to a temperature above the critical range, after which it is cooled in still air to produce a generally fine pearlite structure. The purpose is
to promote uniformity of structure and properties after a hot-working operation such as forging or extrusion. What was the heat treatment involved?
a) Annealing
b) Normalizing
c) Tempering
d) Stress relieving
77. At certain speeds called the critical speeds, a rotating shaft will become dynamically unstable and the resulting vibrations and deflections can result in
damage not only to the shaft but to the machine of which it is a part. At what percentage of the critical speed should a shaft be safely operated?
a) Plus or minus 20%
b) Plus or minus 5 %
c) Plus or minus 10 %
d) Any of these
78. This is the most widely used of all spring materials for small springs operating at temperatures up to about 250 degrees F. It is tough, has a high tensile
strength, and can withstand high stresses under repeated loading.
a) Music wire
b) Hard drawn spring wire
c) Oil tempered spring wire
d) Stainless steel spring wire
79. It is an acronym in machining. This process uses an electrode to remove metal from a workpiece by generating electric sparks between conducting
surfaces.
a) MIG
b) GMAW
c) EDM
d) CNC
Ans. Electro-Discharge Machining (Source: Machinery’s Handbook)
80. In die casting accurate parts made of steel, what shrinkage allowance in inches per inch is recommended?
a) 0.011
b) 0.022
c) 0.033
d) 0.044
Ans. 0.022. (Source: Machinery’s Handbook)
81. This are gears used to connect shafts that are non-intersecting and non-parallel. They are a cross between spriral bevel gears and worm gears.
a) Helical gears
b) Hypoid gears
c) Planetary gears
d) Bevel gears
82. This is a type of seal used where some form of relative motion occurs between rigid parts of an assembly.
a) Gasket
b) Distorted seal
c) Vibratory seal
d) Dynamic seal
83. It is a lubrication for roller chains wherein the lubricant is supplied by a circulating pump capable of supplying the chain drive with a continuous flow of
oil inside the chain loop evenly across the chain width and directly at the slack strand.
a) Oil stream lubrication
b) Bath lubrication
c) Drip lubrication
d) Recirculated lubrication
84. In manufacturing, this is the operation of cutting out flat area to some desired shape and is usually the first step in a series of operation.
d) Finishing
a) Turning
b) Facing
c) Blanking
85. An M-code which generally refers to start spindle rotation in a clockwise direction.
a) M03
b) M04
c) M05
d) M06
86. A final operation to improve the polish of a metal and to bring out the maximum luster
a) Finishing
b) Surface grinding
c) Broaching
d) Buffing
87. Machining operations with the proper application of a cutting fluid generally has the following attributes except:
a) Higher cutting speeds
b) Higher feed rates
c) Lengthened tool life
d) Higher cutting accuracy
88. A material of construction (only developed commercially in the late 1940’s concurrently with zirconium) offers the unique combination of wide ranging
corrosion resistance, low density, and high strength.
a) Tungsten
b) Titanium
c) Vanadium
d) Molybdenum
89. Which of the following is the lightest of all structural metals?
a) Aluminum
b) Copper
c) Magnesium
d) Manganese
90. This process reduces internal stresses, caused by machining, cold working, or welding, by heating the steel to a temperature below the critical range
and holding it there long enough to equalize the temperature throughout the piece.
a) Annealing
b) Normalizing
c) Tempering
d) Stress Relieving
91. A free-cutting steel has a higher ______ content than comparable carbon steels.
a) Sulfur
b) Cobalt
c) Nickel
d) Chromium
92. This property designates the steels resistance to the softening effect of elevated temperature.
a) Hot hardness
b) Machinability
c) Toughness
d) Elasticity
93. Use of hard solders, silver solders and smelter solders which have silver, copper, or nickel bases and have melting points above 800 degrees F is
known as_______
a) Soldering
b) Welding
c) Brazing
d) Any of these
94. In braking, the term backstop refers to a brake that is:
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Machine Design & Shop Practice
Refresh Trivia # 1
a) Self locking in one direction b) Self energizing
c) Self locking in both directions
d) Any of these
95. How do you call a fixed crane consisting of a supported vertical member from which extends a horizontal swinging arm carrying a trolley hoist or other
hoisting mechanism?
a) Jib crane
b) Gantry crane
c) Overhead crane d) Tower crane
96. This iron is also known as a ductile cast iron. How do you call this iron?
a) Malleable iron
b) Nodular cast iron
c) White cast iron
d) Gray cast iron
97. It is the ability to deform plastically to compensate for irregularities in bearing assembly. How do you call this?
a) Plasticity
b) Conformability c) Embeddability
d) Elasticity
98. A material of construction (only developed commercially in the late 1940’s concurrently with zirconium) offers the unique combination of wide ranging
corrosion resistance, low density, and high strength.
a) Titanium
b) Tungsten
c) Vanadium
d) Molybdenum
99. Newton’s law of motion that describes that if a force acts to change the state of motion of the body, the body offers a resistance equal and directly
opposite to the force.
a) Second law
b) Third law
c) First law
d) Universal gravitation
100. The most widely used material for machine elements because of its properties of high strength, high stiffness, durability, and relative ease of
fabrication.
a) Zinc
b) Steel
c) Aluminum
d) Copper
1.
2.
3.
4.
5.
6.
7.
8.
Note: The following questions are for your reading and Familiarization
What is this type of roller bearing in which the balls are assembled by the eccentric displacement of the inner ring?
a) Shallow-groove ball bearing
b) Self-aligning ball bearing
c) Filling-slot ball bearing
d) Deep-groove ball bearing
Which if the following is not a type of ball bearing?
a) Shallow-groove ball bearing b) Self-aligning ball bearing c) Filling-lot ball bearing
d) Deep-groove ball bearing
Which of the following ranges of belt speed suggests the most economical designs?
a) 4000 to 4500 fpm
b) 2000 to 3000 fpm c) 3000 to 4000 fpm d) 4000 to 5000 fpm
What do you a wire rope in which the wires and strands are twisted in opposite directions?
a) Long lay
b) Lang lay
c) Regular lay
d) Performed
What do you call a wire rope in which the wires and strands are twisted in same direction?
a) Long lay
b) Lang lay
c) Performed
What is the product of the length and diameter of a bearing?
a) Projected area
b) Shearing area
c) Compressive area
Which gauge is used to check internal threads?
a) Plug gauge
b) Ring gauge
c) Thread plug gauge
When outside diameter of a job is turned in relation to the internal hole, the job should be held:
a) In three-jaw chuck
b) On the lathe mandrel
c) On face plate
d) Non-performed
d) Cross-sectional area
d) Thread ring gauge
d) Between centers
9.
Which of the following is the measure of modulus of elasticity?
a) Accuracy
b) Quality
c) Stiffness
d) Rigidity
10. How do you call the ratio of moment and stress?
a) Strain
b) Contraction
c) Proportional constant
d) Section Modulus
11. For a symmetrical cross-sectional beam, what is the value of flexural stress when the vertical shear stress is at maximum?
a) Infinity
b) Maximum
c) Zero
d) Minimum
12. In a pressure vessel, how do you call the ratio of minimum strength of joint to the strength of the solid joint?
a) Efficiency
b) Performance Factor
c) Joint Efficiency
d) Relative Strength
13. What is the usual factor of safety in a pressure vessel?
a) 2
b) 4
c) 3
d) 5
14. In a lathe machine, how do you call the diameter of the largest workpiece that can be rotated in a chuck or between centers without hitting the bed?
a) Chuck diameter
b) Swing
c) Distance between centers
d) Spindle diameter
15. It is a kind of mandrel made of soft metals or hard wood that is used to prevent the workpiece to be meshed, especially soft metals for thin cylinders.
How do you call this mandrel?
a) Homemade mandrel
b) Taper mandrel
c) Threaded mandrel
d) Gang mandrel
16. It is called as any internal stress that exists in a part at uniform temperature and not acted upon by an external load. What is this type of stress?
a) Residual stress
b) Superposed stress
c) Form stress
d) Control stress
17. How do you call a phenomenon when two touching surfaces have a high contact pressure and when these surfaces have minute relative motion?
a) Pre-stressing
b) Friction
c) Carving
d) Fretting
18. What is this part of headstock of a lathe machine used to transmit power from the spindle?
a) Motor
b) Back gear
c) Headstock spindle
d) Switch
19. When a hot part is cooled suddenly by quenching, there is momentarily a high temperature gradient that induces a stress gradient. Some metal parts
under certain conditions crack as a result. What is this phenomenon?
a) Thermal-shock failure
b) Thermal fatigue
c) Honing
d) Quenching
20. Fatigue strength is increased by repeated loads just below the normal fatigue limit and followed by small step-by-step increases of the loading. What is
this?
a) Mixing
b) Coaxing
c) Axing
d) Relieving
21. How do you call an axial distance that a screw advances in one turn or revolution?
a) Lead
b) Circular pitch
c) Pitch
d) Axial pitch
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Machine Design & Shop Practice
Refresh Trivia # 1
22. What is a screw fastener with a nut on it?
a) Bolt
b) Rivet
c) Fastener
d) Square screw
23. It is a type of bolt distinguished by a short portion of shank underneath the head, being square or finned or ribbed. What is this bolt?
a) Coupling bolt
b) Machine bolt
c) Stud bolt
d) Carriage bolt
24. How do you call a large wood screw that is used to fasten machinery and equipment to a wooden base?
a) Lag screw
b) Wood screw
c) Log screw
d) Square screw
25. How do you call the ratio of mean diameter of coil and the coil diameter of a spring?
a) Wahl number
b) Diameter ratio
c) Spring index
d) Lead angle
26. It is a low cost spring material, suitable where service is not severe and dimensional precision is not needed. How do you call this spring material?
a) Hard drawn wire
b) helical spring wire
c) Stainless steel
d) helical tension spring wire
27. How do you call a spring material that is hard drawn (80 % reduction) but made up of high-grade steel?
a) Music wire
b) Oil tempered wire
c) Song wire
d) Chromium-silicon wire
28. It is a spring wire with good quality for impact loads and moderately high temperatures. What is this spring material?
a) Hard drawn spring wire
b) helical spring wire
c) Chromium-silicon
d) Helical tension wire
29. It is a type of coil spring where the helical coil is wrapped into a circle forming an annular ring. How do you call this spring?
a) Volute spring
b) Motor spring
c) Hair spring
d) Garter spring
30. It is a type of spring where thin flat strip wound up on itself as a plane spiral, usually anchored at the inside end. What do you call this spring?
a) Volute spring
b) Motor spring
c) Hair spring
d) Garter spring
31. What do you call a ratio of the length of the column and the radius of gyration of the cross-sectional area about the centroidal axis?
a) Power factor
b) Contact ratio
d) Constant ratio
d) Slenderness ratio
32. A screw that requires a positive torque to lower the load, or to loosen the screw if it has been turned tight against a resistance. How do you call this
screw?
a) Power screw
b) Self screw
c) Lock screw
d) Self-locking screw
33. What is the other term used for Kennedy key?
a) Tangential key
b) Normal key
c) Saddle key
d) Rollpin key
34. Which of the following device used to measure the speed accurately?
a) Dial gage
b) Dial indicator
c) Speedometer
d) Tachometer
35. When the hole is smaller than the shaft, it will take pressure to put the parts together. The allowance is said to be negative and is termed as:
a) Interference of metal b) Negative allowance
c) Negative tolerance
d) Negative fits
36. When two elastic bodies collide, which of the following laws can be used to solve for the resulting velocity?
a) Avogadro’s law
b) Conservation of momentum and conservation of energy
c) Dalton’s law of partial pressure
d) Conservation of energy
37. What is the ability of metal to be deformed considerably without rupture?
a) Toughness
b) Stiffness
c) Plasticity
d) Ductility
38. It is a science of motion that can be solved in terms of scalar or vector algebra. How do you cal this science?
a) Kinematics b) Dynamics of machine
c) Engineering mechanics
d) Strength of materials
39. A system of forces in space is in equilibrium. If two equal and opposite collinear forces are added, which of the following if any is true?
a) Forces are in opposite directions
b) Equilibrium is destroyed
c) Equilibrium is maintained
d) An unbalanced of moment exist
40. It is a metal that assists lubrication or lubricant in itself. What is this metal?
a) Lead
b) Babbit
c) Zinc
d) Antimony
41. What do you call a mechanism that usually does the indexing in a machine tool?
a) Indexing machine
b) Dividing head
c) Slotter
c) Universal chuck
42. The machine element equalizes the energy exerted and the work done thus preventing excessive or sudden changes of speed. What is this machine
element?
a) Pulley
b) Gear
b) Flywheel
d) Shaft
43. How do you call the product of the resultant of all forces acting on a body and the time that the resultant acts?
a) Linear momentum
b) Linear impulse
c) Angular momentum
c) Angular impulse
44. Which of the following is not a structure class of steel?
a) High strength low alloy steel
b) High chrome alloy steel
c) Tool and die steel
d) Low carbon steel
45. Poison ratio is defined as the ratio of which of the following?
a) Lateral strain and longitudinal strain
b) Shear strain and compressive strain
c) Elastic limit and proportional limit
d) Elastic limit and compressive strain
46. How do you call a property of material that relates the lateral strain to the longitudinal strain?
a) Stress
b) Poison’s ratio
c) Modulus of resilience
d) Strain
47. This is a maximum stress to which a material may be subjected before failure occurs. What do you call this maximum stress?
a) Ultimate stress
b) Endurance limit
c) Yield stress
c) Ultimate strength
48. It deals only with the motion of bodies without reference to the forces that cause them. What is this?
a) Dynamics
b) Kinetics
c) Kinematics
d) Static
49. It is the circle on gear that corresponds to the contact surface of the friction wheel. How do you call this circle?
a) Pitch circle
b) Addendum circle c) Base circle
d) Dedendum circle
50.
It is the circle drawn through the top of the gear tooth; its center is at the gear center. What is this circle?
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Machine Design & Shop Practice
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Refresh Trivia # 1
a) Pitch circle
b) Addendum circle
c) Base circle
d) Dedendum circle
What is the radial distance from the pitch circle to the addendum circle of a spur gear?
a) Addendum
b) Dedendum
c) Clearance
d) Space width
This circle is drawn through the bottom of the gear tooth; its center is at the gear center. What do you call this circle?
a) Pitch circle
b) Addendum circle
c) Base circle
d) Dedendum circle
The largest circle centered at the gear center, which is not penetrated by the teeth of the mating gear. It is a circle tangent to the addendum circle of the
mating gear. What is this circle?
a) Pitch circle
b) Addendum circle
c) Clearance circle
d) Dedendum circle
This radial distance of a gear is measured from the clearance circle to the root circle, and is the difference between the dedendum of one gear and
addendum of the mating gear. What is this radial distance?
a) Addendum
b) Dedendum
c) Clearance
d) Space width
This radial distance in a gear is measured between the addendum and dedendum circle, snd is the sum of the addendum and the dedendum? How do
you call this distance?
a) Addendum
b) Whole depth
c) Working depth
d) Space width
This minimum distance is measured between the non-driving side of a tooth and the adjacent side of the mating tooth. It is the amount by which the
width of a tooth space exceeds the thickness of the engaging tooth measured on the pitch circle. What is this distance?
a) Circular pitch
b) Whole depth
c) Backlash
d) Space width
It is an arc of the pitch circle of a spur gear through which a tooth travels from the first point of contact with the mating tooth to the point where the
contact ceases. What is this arc?
a) Arc of action
b) Arc of approach
c) Tooth profile
d) Involute curve
It is an arc of the pitch circle of a spur gear through which a tooth travels from the point of contact with the mating tooth to the pitch point. What is this
arc?
a) Arc of action
b) Arc of approach c) Arc of recess
d) Involute curve
What is an arc of the pitch circle of a spur gear through which a tooth travels from its contact with the mating tooth at the pitch point where the contact
ceases?
a) Arc of action
b) Arc of approach
c) Arc of recess
d) Involute curve
What is the angle between the line drawn from the pitch point perpendicular to the line of centers and the line drawn from the pitch point to the point
where a pair of teeth of gears is in contact?
a) Pressure angle
b) Helix angle
c) Lead angle
d) Angle of approach
How do you call the circle from which an involute tooth of a spur gear is generated or developed?
a) Pitch circle
b) Addendum circle
c) Base circle
d) Dedendum circle
What do you call an angle in the base cylinder of an involute spur gear that the tooth makes with the gear axis?
a) Pressure angle
b) Base helix angle
c) Lead angle
d) Angle of approach
What is the pitch on the base circle or along the line of action of an involute spur gear?.
a) Axial base pitch of an involute gear
b) Normal pitch of an involute gear
c) Angle of approach of an involute gear
d) Base pitch of an involute gear
This is the distance between the parallel axes of spur gears or parallel helical gears, or the distance between the crossed axes of helical gears and
worm gears. It can be defined also as the distance between the centers of pitch circles. What is this distance?
a) Addendum
b) Center distance
c) Clearance
d) Space width
This is the width of the tooth measured along the pitch circle. How do you call this tooth width of a gear?
a) Circular thickness
b) Chordal thickness
c) Tooth space
d) Face width
The tooth width measured along the chord at the pitch circle is known as:
a) Circular thickness
b) Chordal thickness
c) Tooth space
d) Face width
The space between teeth measured along the pitch circle is called:
a) Circular thickness
b) Chordal thickness
c) Tooth space
The length of teeth in an axial direction is called as:
a) Circular thickness
b) Chordal thickness
c) Tooth space
The surface of the tooth between the pitch cylinder and the addendum cylinder is said to be:
a) Tooth face
b) Chordal thickness
c) Tooth space
The surface of the tooth between the pitch and root cylinders is said to be:
a) Circular thickness
b) Tooth flank
c) Tooth space
The surface of the top of the tooth of a gear is known as:
a) Tooth top land
b) Tooth bottom land
The surface of the bottom of the tooth space is said to be:
a) Circular thickness
b) Chordal thickness
d) Face width
d) Face width
d) Face width
d) Face width
c) Tooth space
d) Face width
c) Tooth space
d) Tooth bottom land
Circular Pitch is the distance measured along the pitch circle from a point on one tooth to the corresponding point on the adjacent tooth of the gear.
a) Circular thickness
b) Diametral pitch
c) Circular pitch
d) Tooth bottom land
It is the number of teeth per inch of the pitch diameter. This is also a number or parameter used to determine the sizes of gears in the English system.
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Machine Design & Shop Practice
a) Circular thickness
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Refresh Trivia # 1
b) Diametral pitch
c) Circular pitch
d) Module
The ratio of the pitch diameter to the number of teeth; it is a number used to determine and specify gear sizes in the metric system.
a) Circular thickness
b) Diametral pitch
c) Circular pitch
d) Module
“The shape (profile) of the tooth of a gear must be such that the common normal at the point of contact between two teeth always passes through a
fixed point on the line of centers of the gears.” The preceding statement is known as:
a) Grashof’s law
b) Coriolli’s law
c) Klein’s law
d) Fundamental law of gearing
A curve described by a point on a circle that rolls internally or externally on another circle is said to be:
a) Arc of action
b) Arc of approach
c) Involute curve
d) Cycloid curve
The path generated by a tracing point on a cord as the chord is unwrapped from a cylinder called the base cylinder
a) Arc of action
b) Arc of approach
c) Involute curve
d) Cycloid curve
For two externally meshing gears, which of the following is incorrect?
a) The same direction of rotation
b) The same diametral pitch
c) The same circular pitch
d) The same addendum
For two internally mashing gears, which of the following is incorrect?
a) Opposite directions of rotation
b) The same diametral pitch
c) The same circular pitch
d) The same addendum
A rotating or stationary member, usually of circular cross section much smaller in diameter than its length, used to transmit motion or power; having
mounted on it such power-transmitting elements as gears, pulleys, belts, chains, cam, flywheels, cranks, sprockets, and rolling-element bearings.
a) Gear
b) Flywheel
c) Shaft
d) Cam
82.
A non-rotating member that carries no torque and is used to support rotating wheels, pulleys, and the like.
a) Spindle
b) Axle
c) Line shaft
d) Counter shaft
83. The geometric shape of bevel gears based on equivalent rolling contact is known as:
a) Pitch cone
b) Cone distance
c) Face cone
d) Root cone
84. The intersection of the elements making up the pitch cone is called as:
a) Pitch cone
b) Cone distance
c) Apex of pitch cone
85. A slant height of the pitch cone. It is the length of a pitch cone element.
a) Pitch cone
b) Cone distance
c) Apex of pitch cone
d) Root cone
d) Root cone
86. The cone formed by the elements passing through the top of the teeth and the apex is known as:
a) Pitch cone
b) Cone distance
c) Face cone
d) Root cone
87. The cone formed by the elements passing through the bottom of the teeth and the apex is said to be:
a) Pitch cone
b) Cone distance
c) Apex of pitch cone
d) Root cone
88. The angle between an element of the face cone and the axis of the gear is known as:
a) Face angle
b) Pitch angle
c) Pitch angle
d) Root angle
89. The angle between an element of the pitch cone and the axis of the gear is called as:
a) Face angle
b) Pitch angle
c) Pitch angle
d) Root angle
90. It is the angle between an element of the root cone and the axis of the gear.
a) Face angle
b) Pitch angle
c) Pitch angle
d) Root angle
91. It is the width of a tooth of a bevel gear. How do you call this?
a) Face width
b) Addendum
c) Apex
d) Dedendum
92. It is the distance from an element on the pitch cone to an element on the face cone, measured on the outside of the tooth. What is this distance?
a) Face width
b) Addendum
c) Apex
d) Dedendum
93. It is the distance from an element on the pitch cone to an element on the root cone, measured on the outside of the gear. How do you call this
distance?
a) Face width
b) Addendum
c) Apex
d) Dedendum
94. It the angle between an element on the pitch cone and an element on the face cone.
a) Addendum angle
b) Dedendum angle
c) Pitch angle
d) Root angle
95. The angle between an element on the pitch cone and an element on the root cone is known as:
a) Addendum angle
b) Dedendum angle
c) Pitch angle
d) Root angle
96. The pitch diameter measured on the inside of the tooth is said to be:
a) Inside pitch diameter b) Outside pitch diameter
c) Back cone diameter
d) Root cone diameter
97. It is the pitch diameter measured on the outside of the tooth.
a) Inside pitch diameter
b) Outside pitch diameter c) Back cone diameter
d) Root cone diameter
98. Fatigue strength is increased by repeated loads just below the normal fatigue limit, followed by small step by step increases of the loading, the process
is called as:
a) Mixing
b) Coaxing
c) Axing
d) Relieving
99. It is the diameter of the imaginary cylinder that bounds the crest of an external thread and the roots of an internal thread.
a) Mean diameter
b) Stress diameter c) Minor diameter d) Major diameter
100. It is a type of bolt distinguished by a short portion of shank underneath the head being square or finned or ribbed.
a) Coupling bolt
b) Machine bolt
c) Stud bolt
d) Carriage bolt
101. A type of bolt threaded on both ends and can be used where a through bolt is impossible.
a) Coupling bolt
b) Machine bolt
c) Stud bolt
10
d) Carriage bolt
Machine Design & Shop Practice
Refresh Trivia # 1
102. If the band wraps partly around the brake wheel or drum, and braking action is obtained by pulling the band tight onto the wheel.
a) Block brake
b) Band brake
c) Clutch
d) Centrifugal brake
103. A clutch has a disadvantage of heavier rotating masses.
a) Multiple disc clutch
b) Disc clutch
104. Devise used to measure an accurate speed:
a) Speedometer
b) Dial Indicator
c) Cone clutch
d) Band brake
c) Tachometer
d) Dial Gauge
105. When the hole is smaller than shaft, it will take pressure to put the parts together. The allowance is said to be negative and is termed as:
a) Negative tolerance
b) Negative allowance
c) Negative fits
d) Interference of metal
106. When two elastic bodies collide, which of the following laws can be used to solve for the resulting velocity?
a) Dalton’s law
b) Avogadro’s law
c) Conservation of energy
d) Conservation of momentum and conservation of energy
107. The ability of a metal to be deformed considerably without rapture is called as:
a) Plasticity
b) Ductility
c) Malleability
108. Permanent deformation or strain may occur without fracture:
a) Malleability
b) Elasticity
c) Ductility
d) Plasticity
109. It is a science of motion that can be solved in terms of scalar or vector algebra:
a) Kinematics b) Curvilinear translation
c) Projectiles
d) Acceleration
d) Rigidity
110. A system of forces in space is in equilibrium. If two equal and opposite collinear forces are added, which of the following if any is true?
a) Equilibrium is destroyed
b) Equilibrium is maintained
c) An unbalanced of moment exist
d) None of these is true
11
MACHINE DESIGN/SHOP PRACTICE
JCSF ENGINEERING REVIEW CENTER
2nd Floor Santos-Causing Building, National Highway
Halang, City of Calamba, Laguna
MACHINE DESIGN AND SHOP PRACTICE
(Refreshers Trivia # 2)
Prepared by: Jose R. Francisco, PME
March 2012
MULTIPLE CHOICE QUESTIONS
Select the best answer from each of the following questions. On the answer sheet provided, shade the box that corresponds to your choice. Strictly no
erasures allowed.
1.
Select a deep-groove ball bearing to carry a radial load Fx = 800 lb and a thrust load Fz = 700 lb at 1800 rpm. The service is 8 hr/day, but it is not
continuous; design for 18 250 hr. The operation is smooth with little vibration; the outer ring rotates. Determine the design life in million revolution (mr)
with no more than 10 % failure.
a) 1791 mr
b) 1971 mr
c) 1197 mr
d) 1917 mr
Solution:
2.
(18 250)(60)(1 800)
10 6
= 1971 mr
If the ultimate shear strength of a steel plates is 42 000 psi, what force is necessary to punch a 0.75 inch diameter hole in a 0.625 inch thick plate?
a) 61 850 lb
b) 65 810 lb
c) 61 580 lb
d) 60 185 lb
Solution:
3.
B10 = (Hrs )(60 min s / hr )(rpm ) =
(
)
F = s u A s = s u (πd t ) = 42000 lb / in 2 (π )(0.75 in )(0.625 in ) = 61 850.1 lb
Find the pressure required to punch a 1-inch square hole in ¼ -inch thick steel.
a) 20.67 tons
b) 26.76 tons
c) 26.67 tons
Solution:
o
d) 26.67 tons
⎛ 4⎞⎛ 1 ⎞
F = 80 D T = 80⎜ ⎟ ⎜ ⎟ = 26.67 tons
⎝ 3⎠⎝ 4⎠
Pressure Required for Punching.—The formula for the force in tons required to punch a circular hole in sheet steel is, F =
π D ss t
2 000
, where ss =
the shearing strength of the material in psi; t = thickness of the steel in inches, and 2000 is the number of lb in 1 ton. An approximate formula is,
F = D t (80) , where D and T are the diameter of the hole and the thickness of the steel, respectively, both in inches, and 80 is a factor for steel.
o
o
4.
The result is the force in tons.
If the hole is not circular, replace the hole diameter with the value of one-third of the perimeter of the hole to be punched.
The corresponding factor for punching holes in brass is 65 instead of 80.
(Source: Machinery’s Handbook 26, p1303)
What length of a square key is required for a 4-in diameter shaft transmitting 1000 hp at 1000 rpm? The allowable shear and compressive stresses in
the key are 15 ksi and 30 ksi, respectively.
a) 2.1 inches
b) 2.8 inches
c) 3.2 inches
d) 4.2 inches
Solution: Transmitted torque, T =
63000 Hp 63000(1000 )
=
= 63 000 in ⋅ lb
n
1000
D
, for good proportion
4
2T
2 (63 000 )
=
= 2.1 inches
Key length based on shear, L =
s s bD 15 000 (1)(4)
Key width,
b≈
Key length based on compression,
5.
Therefore, use L = 2.1 inches
nb =
8T
8 (15 000)
=
= 8.5 bolts
2
π s sb d D b π (3000 )(0.5)2 (6 )
Use, nb = 9 bolts
Determine the radius of gyration of a wheel that has an outside and inside diameters of 1 meter and 0.75 meter, respectively? Neglect its hub and
arms.
a) 0.5125 m
b) 0.6125 m
c) 0.3125 m
d) 0.4125 m
Solution: k =
7.
4T
4 (63 000 )
=
= 2.1
s c t D 30 000 (1)(4)
A flange coupling is to transmit 15,000 in-lb between two 2.5” diameter shafts. How many ½” diameter bolts in a 6” diameter bolt circle are required if
the shear stress in each bolt is limited to 3000 psi?
a) 9 bolts
b) 7 bolts
c) 6 bolts
d) 8 bolts
Solution: No. of bolts,
6.
L=
I
=
A
(
(
)
)
π
D o4 − D i4
64
=
π 2
D o − D i2
4
1
16
(
)(
⎡ D o2 + D i2 D o2 − D i2
⎢
⎢⎣
D o2 − D i2
)⎤⎥ = 1
⎥⎦
4
D o2 + D i2 = 0.3125 in .
What is the polar section modulus of a solid shaft with a diameter of 101.6 mm?
3
4
3
b) 209.5 cm
c) 205.9 cm
a) 209.5 cm
1
4
d) 205.9 cm
MACHINE DESIGN/SHOP PRACTICE
8.
If the ultimate shear strength of a steel plates is 42 000 psi, what force is necessary to punch a 0.75 inch diameter hole in a 0.625 inch thick plate?
a) 61 850 lb
b) 65 810 lb
c) 61 580 lb
d) 60 185 lb
Solution:
9.
J 2J π 3 π
=
=
D = (10.16 )3 = 205.9 cm 3
c D 16
16
Zj =
Solution:
(
)
F = s u A s = s u (πd t ) = 42000 lb / in 2 (π)(0.75 in )(0.625 in ) = 61 850.1 lb
Determine the tensile stress area of an American Standard Screw Threads 6-32 UNC with basic major diameter of 0.1380 inch.
-3
2
-2
2
-4
2
-5
2
b) 9.085 x 10 in
c) 9.085 x 10 in
d) 9.085 x 10 in
a) 9.085 x 10 in
⎛
Solution: For American Standard Screw Threads: A t = 0.7854⎜ D −
⎝
0.9743 ⎞
⎟
n ⎠
2
2
Where At = tensile Stress Area, in ; D = basic major diameter, in.; n = no. of threads per inch
2
0.9743 ⎞
⎛
A t = 0.7854⎜ 0.1389 −
⎟ = 9,085 x 10 −3 in 2
28 ⎠
⎝
10. What is the number of threads per mm and the tensile stress area of a standard Metric screw Thread designated by M10 x 1.5?
2
2
2
2
c) 1.5 and 57.99mm
d) 1.75 and 57.99 mm
a) 0.555 and 57.99 mm b) 0.667 and 57.99 mm
Solution:
n=
1
1
=
= 0.667 threads per mm
p 1.5
For Standard Metric Screw Threads,
A t = 0.7854(D − 0.9383p )2 = 0.7854[10 − 0.9383(2.5)]2 = 57.99 mm 2
2
D = basic major diameter, mm; p = pitch, mm
Where At = tensile stress Area, mm ;
Note: M stands for standard metric screw threads; 10 stands for the basic major diameter, which is 10 mm;
1.5 stands for pitch that is 1.5 mm.
11. A line shaft is to transmit 200 Hp at 900 rpm. Find the diameter of the shaft.
a) 2.18 inches
b) 2.28 inches
c) 3.18 inches
d) 3.28 inches
Solution:
D=3
53.5 P
53.5(200 )
=3
= 2.28 inches
N
900
Note: For Main Power Transmitting Shaft:
For Small, Short Shaft:
P=
P=
D3N
38
D3 N
80
Where,
For Line Shaft Carrying Pulleys:
P = transmitted power, Hp
P=
N = shaft rpm
D3N
53.5
D = shaft diameter, in inches
12. A 1.75-inch-diameter shaft is supported by two sleeve bearings. The total load on the two bearings is 2800 lb. Find the friction power loss, in Hp, if the
coefficient of friction between shaft and bearing is 0.10 and the shaft rotates 200 rpm.
a) 0.88 Hp
b) 0.78 Hp
c) 0.98 Hp
d) 0.68 Hp
Solution:
T n
f Fr n
fHp = f
=
=
63 000 63 000
⎛ 1.75 ⎞
0.10(2 800)⎜
⎟(200 )
⎝ 2 ⎠
= 0.78
(63 000)
F = load, lb
n = rpm
r = bearing diameter, inches
Tf = frictional torque, in-lb
f = coefficient of friction
13. Determine the Hp lost when a collar is loaded with 2000 lb, rotates at 50 rpm, and has a coefficient of friction of 0.15. The outside diameter of the collar
is 4 inches and the inside diameter is 2 inches.
a) 0.7314 Hp
b) 0.3714 Hp
c) 0.4713 Hp
d) 0.4371 Hp
Where,
Solution:
Where,
fHp =
rf =
Tf n
f W rf n 0.15(2000 lb )(1.56 inches )(50 rpm )
=
=
= 0.3714
63000
63000
63000
3
3
2 ⎛⎜ ro − ri ⎞⎟ 2 ⎡ (2 )3 − (1)3 ⎤
= ⎢
⎥ = 1.56 inches
3 ⎜ ro2 − ri2 ⎟ 3 ⎢⎣ (3)2 − (1)2 ⎥⎦
⎝
⎠
2
14. A vertical steel cylinder water tank is 30 m in diameter and 45 m high. The allowable stress of the steel plate is 1224 kg/cm . Without reinforcing
angle bars and rods, what is the thickness of the steel plate?
a) 55.15 mm
b) 51.55 mm
c) 65.15 mm
d) 61.55 mm
Solution:
Where,
t=
(
)
pD
441 297 N / m 2 (30 m )
=
= 0.05515 m = 55.15 mm
2 s t E j 2 1224 kg / cm 2 (9.8066 N / kg )(100 cm / m )2
(
)
p = maximum pressure inside the tank, Pa
(
)(
)
p = ρ g H = 1000 kg / m 3 9.8066 m / s 2 (45 m ) = 441 297 Pa
st = hoop stress of the tank, Pa
15. What is the bursting steam pressure of a hemispherical steel shell with a diameter of 100 inches and made of 0.0635-m thick steel plate, if the joint
efficiency is 70 % and the tensile strength is 60 000 psi?
a) 4 020 psi
b) 4 200 psi
c) 2 400 psi
d) 2 040 psi
Solution:
p=
4 t sl E j
D
(
)
⎛ 63.5 ⎞
4⎜
in ⎟ 60 000 lb / in 2 (0.70 )
⎝ 25.4 ⎠
=
= 4 200 psi
100 in.
2
MACHINE DESIGN/SHOP PRACTICE
Where, p = bursting pressure, psi
t = shell thickness, inches
sl = shell stress, psi
D = shell diameter, inches
Ej = joint efficiency
Note: For the longitudinal stress of the thin-walled cylinder, and the stress for spherical tank:
pD
sL =
4tEj
16. The root diameter of a double square thread is 0.55 inch. The screw has a pitch of 0.2 inch. Find the outside diameter and the number of thread per
inch.
p
a) 0.2 threads/inch
b) 10 threads/inch
c) 5 threads/inch
d) 2.5 threads/inch
Solution:
Solving for the outside or major diameter, Do = Di + p = 0.55 + 0.2 = 0.75 inch
Solving for the number of threads per inch,
TPI =
1
1
=
= 5 threads / inch
p 0.2
Di = 0.55”
Lead
17. A flat belt is 6 inches wide and 1/3 inch thick and transmits 15 Hp. The center distance is 8 ft. The driving pulley is 6 inches in diameter and rotates at 2
3
000 rpm such that the loose side of the belt is on top. The driven pulley is 18 inches in diameter. The belt material is 0.035 lb/in and the coefficient of
friction is 0.30. Determine the belt net tension.
a) 175.5 lb
b) 157.5 lb
c) 155.7 lb
d) 165.7 lb
F = F1 − F2 =
Solution:
2 T 2 ⎛ 63 000 Hp ⎞ ⎛ 2 ⎞ ⎡ 63 000(15) ⎤
= ⎜
⎟ = ⎜ ⎟⎢
⎥ = 157.5 lb
D
D⎝
n
⎠ ⎝ 6 ⎠ ⎣ 2 000 ⎦
⎛ 6⎞
⎟(2 000) = 3141.59 fpm
⎝ 12 ⎠
Other Solution: Vm = π D n = π⎜
F = F1 − F2 =
33 000 Hp 33 000(15)
=
= 157.56 lb
Vm
3141.59
18. A roller chain and sprocket is to drive vertical centrifugal discharge bucket elevator. The pitch of chain connecting sprockets is 1.75”. The driving
sprocket is rotating at 120 rpm and has 11 teeth while the driven sprocket is rotating at 38 rpm. Determine the number of teeth of driven sprocket.
a) 33 teeth
b) 35 teeth
c) 30 teeth
d) 34 teeth
⎛n
T2 = T1 ⎜⎜ 1
⎝ n2
Solution:
⎞
120 ⎞
⎟ = (11)⎛⎜
⎟ = 34.74 ≈ 35 teeth
⎟
38 ⎠
⎝
⎠
19. A helical steel spring has a maximum load of 800 lb and a corresponding deflection of 2 inches. If it has 8 active coils and an index of 6, what minimum
shear strength of the spring material is required?
a) 57 ksi
b) 47 ksi
c) 67 ksi
d) 37 ksi
Solution:
k=
F GD w
=
δ 8C3 N c
Wahl Factor,
Dw =
Kw =
Torsional stress,
8C3 N c F 8 (6 ) (8)(800)
=
= 0.477 inch
δG
2 11.6 x 106
3
(
4C − 1 0.615 4(6) − 1 0.615
+
=
+
= 1.2525
4C − 4
C
4(6) − 4
6
⎛ 8FC
s s = K w ⎜⎜
2
⎝ π Dw
)
⎡ 8 (800 )(6) ⎤
⎞
⎟ = 1.2525⎢
= 67 286 psi
2⎥
⎟
⎠
⎣ π (0.477 ) ⎦
20. A helical-coil spring has a mean coil diameter of 1 inch and a wire diameter of 1/8 inch. Determine the value of Bergstrasssar factor of the spring.
a) 1.172
b) 1.712
c) 1.217
d) 1.271
Solution:
C=
Dm
1
=
=8
1
d
8
KB =
4C + 2 4(8) + 2
=
= 1.1724
4C − 3 4(8) − 3
21. A precision cut gear transmits 25 Hp at a pitch line velocity of 6000 fpm. If the service is intermittent, find the dynamic load.
a) 247.05 lb
b) 274.05 lb
c) 275.04 lb
d) 247.05 lb
Solution:
Ft =
33 000 Hp (33 000 )(25)
=
= 137.5 lb
Vm
6 000
⎛ 78 + Vm
Fd = ⎜
⎜
78
⎝
⎞
⎛
⎟ F = ⎜ 78 + 6000
d
⎟
⎜
78
⎝
⎠
⎞
⎟ (137.5) = 274.05 lb
⎟
⎠
22. What is the difference of the values of the Wahl factor and the Bergstrasser factor, in percentage?
a) 1 %
b) Less than 1 %
c) Greater than 1 %
d) 0.5 %
23. A double-thread worm has a pitch diameter of 3 inches. The wheel has 20 teeth and a pitch diameter of 5 inches. Find the gear helix angle.
o
o
o
o
b) 9.46
c) 6.49
d) 6.94
a) 4.69
⎡⎛ T
λ = tan −1 ⎢⎜⎜ w
⎢⎣⎝ Tg
Solution:
⎞⎛ D g
⎟⎟⎜
⎜
⎠⎝ D w
⎞⎤
⎡
⎤
⎟⎥ = tan −1 ⎢ 2 ⎛⎜ 5 ⎞⎟⎥ = 9.46 o
⎟
⎣ 20 ⎝ 3 ⎠⎦
⎠⎥⎦
24. A helical-coil spring has a mean coil diameter of 1 inch and a wire diameter of 1/8 inch. Determine the shear-stress augmentation factor of the spring.
a) 1.625
b) 1.0625
c) 1.0256
d) 1.0526
Solution:
C=
Dm
1
=
=8
1
d
8
Ks =
2C + 1 2(8) + 1
=
= 1.0625
2C
2(8)
3
MACHINE DESIGN/SHOP PRACTICE
25. A disc clutch has 6 pairs of contacting friction surfaces with an outside diameter of 200 mm and an inside diameter of 100 mm. The coefficient of friction
of the clutch materials is 0.4 and the axial force is 1500 N. The shaft speed is 1200 rpm. Determine the Hp that can be transmitted by the clutch
assuming uniform pressure.
a) 35.2 Hp
b) 23.5 Hp
c) 47.2 Hp
d) 27.4 Hp
3
3
2 ⎛⎜ ro − ri ⎞⎟ ⎛ 2 ⎞ ⎡ (100 )3 − (50)3 ⎤
= ⎜ ⎟⎢
⎥ = 77.78 mm
3 ⎜ ro2 − ri2 ⎟ ⎝ 3 ⎠ ⎢⎣ (100 )2 − (50)2 ⎥⎦
⎝
⎠
Friction Radius (Uniform pressure), rf =
Solution:
Friction Power or Transmitted Power or Power Capacity,
P=
π n Tf
πn
(Ff rf n f ) = π n (f Fa rf n f ) = π(1200) (0.4)(1.5)(0.07778)(6)
=
30
30
30
30
P = 35.19 kW = 47.2 Hp
P = power capacity, kW
Ff = friction force, kN
Rf = friction radius or mean radius, m
Fa = axial load, kN
Where,
Tf = torque capacity, kN-m
nf = no. of pairs of contacting friction surfaces
26. A flywheel has a mean diameter of 4 ft and is required to handle 2250 ft-lb of kinetic energy. It has a width of 8 inches, mean operating speed is 300
rpm and the coefficient of fluctuation is to be 0.05. Find the weight of rim, assuming that the arms and hub are equivalent to 10 % of the total rim weight.
The flywheel is made up of cast iron with specific weight of 0.26 lb per cubic inch.
a) 333.7 lb
b) 373.3 lb
c) 337.3 lb
d) 733.3 lb
Solution: ∆KE =
Where,
1.10 W
Cf V 2
g
g (∆KE )
W=
1.10 C f V
V = mean velocity =
2
=
32.2(2250 )
1.10(0.05)(62.83)2
πDn π(4 )(300)
=
= 62.83 fps
60
60
g = acceleration due to gravity = 32.2 fps
= 333.7 lb
Cf = coefficient of fluctuation
∆KE = Kinetic Energy
2
o
27. A 20 involute spur gear has a tooth whole depth of 16.95 mm, a tooth thickness of 13.2 mm, and a pitch of 3. Determine the circular pitch of the gear.
a) 26.6 mm
b) 16.6 mm
c) 25.6 mm
d) 24.6 mm
Solution:
Pc =
π
π
= = 1.0472 inches = 26.6 mm
Pd 3
o
28. A parallel helical gear-set consists of a 19-tooth pinion driving a 57-teeth gear. The pinion has a left-hand helix angle of 20 , a normal pressure angle of
o
14½ , and a normal diametal pitch of 10 teeth/inch. If the pinion is to transmit 50 Hp at a speed of 1750 rpm. Determine the center distance of the two
gears.
a) 2.02 inches
b) 6.06 inches
c) 4.04 inches
d) 2.06 inches
Solution: Pdn =
Tp
Tg
Pd
=
=
cos ψ D p cos ψ D g cos ψ
Pitch diameter of the pinion, D p =
⎛ Tg
⎜ Tp
⎝
D p + Dg
Pitch Diameter of the gear, D g = D p ⎜
Center-to-center distance, C =
2
Tp
Pdn cos ψ
=
19
10 cos 20 o
= 2.02 inches
⎞
⎟ = 2.02⎛⎜ 57 ⎞⎟ = 6.06 inches
⎟
⎝ 19 ⎠
⎠
=
2.02 + 6.06
= 4.04 inches
2
29. A right-handed single-thread hardened-steel worm has a catalog rating of 2.25 kW at 650 rpm when meshed with a 48-tooth cast-steel gear. The axial
o
pitch of the worm is 25 mm, normal pressure angle is 14.5 , and the pitch diameter of the worm is 100 mm. The coefficient of friction is 0.085.
Determine the shafts center distance.
a) 241 mm
b) 142 mm
c) 412 mm
d) 124 mm
Solution:
Speed Ratio, SR =
Tanλ =
Tg
D g cos λ
Dg
ωw n w
=
=
=
=
ωg
ng
Tw D w sin λ D w tan λ
p
L
25
=
=
= 0.07958
πD w πD w π(100 )
→ λ = 4.55 o
⎛ Tg ⎞
⎛T ⎞
⎛
⎞ ⎛T
⎟ D tan λ = ⎜ g ⎟D w ⎜ p ⎟ = ⎜ g
⎜ πD ⎟ ⎜ T
⎜T ⎟ w
⎜T ⎟
w ⎠ ⎝ w
⎝
⎝ w⎠
⎝ w⎠
D w + D g 100 + 381.97
=
= 241 mm
Center Distance, C =
2
2
Pitch diameter of the gear, D g = ⎜
⎞⎛ p ⎞ ⎛ 48 ⎞⎛ 25 ⎞
⎟⎜ ⎟ = ⎜ ⎟⎜ ⎟ = 381.97 mm
⎟⎝ π ⎠ ⎝ 1 ⎠⎝ π ⎠
⎠
o
30. A 20 straight-tooth bevel pinion having 14 teeth and a diametral pitch of 6 teeth/inch drives a 42-tooth gear. The two shafts are at right angles and in
the same plane. Find the pitch angle of the pinion.
o
o
o
o
b) 20
c) 14.5
d) 20.5
a) 18.4
Solution: γ = tan
⎛ Tp
⎜ Tg
⎝
−1 ⎜
⎞
⎟ = tan −1 ⎛⎜ 14 ⎞⎟ = 18.4 o
⎟
⎝ 42 ⎠
⎠
o
31. A triple-thread worm has a lead angle of 17 and a pitch diameter of 2.2802 inches. Find the center distance when the worm is mated with a wheel of
48 teeth.
a) 6.72 inches
b) 7.26 inches
c) 6.27 inches
d) 7.62 inches
4
MACHINE DESIGN/SHOP PRACTICE
⎛ Tg ⎞
⎟D tan λ = ⎛⎜ 48 ⎞⎟(2.2802 ) tan 17 o = 11.154 inches
Solution: D g = ⎜
⎜T ⎟ w
⎝ 3 ⎠
⎝ w⎠
C=
Dw + Dg
2
=
2.2802 + 11.154
= 6.72 inches
2
o
32. A 36-tooth pinion turning at 300 rpm drives 120-tooth gear of 14.5 involute full depth pressure angle. Determine the rpm of the driven gear.
a) 60 rpm
b) 45 rpm
c) 75 rpm
d) 90 rpm
⎛ Tp ⎞
⎟ = (300 )⎛⎜ 36 ⎞⎟ = 90 rpm
⎟
T
⎝ 120 ⎠
g
⎝
⎠
Solution: n g = n p ⎜
⎜
33. A single square thread power screw is to raise a load of 70 kN. The screw has a major diameter of 36 mm and a pitch of 6 mm. The coefficient of
thread friction and collar friction are 0.13 and 0.10 respectively. If the collar mean diameter is 90 mm and the screw turns at 60 rpm, find the axial linear
speed of the screw.
a) 5 mm/s
b) 6 mm/s
c) 7 mm/s
d) 5.5 mm/s
Solution: For the linear speed of the screw, Vn = n (L) = (60 rpm)(6 mm/rev) = 360 mm/min = 6 mm/s
34. What is the minimum clearance allowed for meshing spur gears with diametral pitch of 20? The spur gear has 25 teeth.
a) 0.00785 inch
b) 0.00758 inch
c) 0.00857 inch
d) 0.00758 inch
Solution:
c=
0.157 0.157
=
= 0.00785 inch
pd
20
(Vallance, page 262)
35. A wire rope lifts a load of 10 kips at a maximum speed of 1000 feet per minute, attained in 5 seconds starting from rest. The rope has a metallic cross
2
sectional area of 0.4 in . Determine the maximum tensile stress on the rope in ksi.
a) 26.2
b) 25.0
c) 27.6
d) 32.4
Solution:
a=
V1 − Vo (1000 / 60 ) − 0
=
= 3.33 fps 2
t
5
St =
⎛
a⎞
3.33 ⎞
⎛
F = WL ⎜⎜1 + ⎟⎟ = (10 000) ⎜1 +
⎟ = 11 034.16 lb
g
32
.2 ⎠
⎝
⎝
⎠
11,034.16
= 27 585.4 psi = 27.6 ksi
0.4
36. A casting weighing 300 pounds is to be lifted by means of an overhead crane. The casting is lifted 10 feet in 12 seconds. What is the horsepower
developed?
a) 0.54
b) 0.84
c) 0.95
d) 0.45
⎛
⎜
⎞
⎟
1hp
⎟ = 0.4545hp
⎣12 sec ⎦ ⎜ 550 ft − lb ⎟
⎜
⎟
sec ⎠
⎝
Solution: Power = (Force)(Velocity) = 300lb ⎡ 10ft ⎤ ⎜
⎢
⎥
37. What wall thickness is required for a 500mm diameter cylinder under an internal pressure of 20 MPa? Use a design stress of 80 MPa.
a) 73 mm
b) 53 mm
c) 63 mm
d) 83 mm
Solution: Using thin-walled vessel formula:
St =
for
t
≤ 0.07
D
pD
20(500)
t
> 0.07,∴ use the thick − walled formula
: 80 =
: t = 62.5 mm but
2t
2t
D
D ⎡ S + p ⎤ 500 ⎡ 80 + 20 ⎤
t= ⎢
− 1⎥ : t = 72.7mm
− 1⎥ =
⎢
2 ⎢⎣ 80 − 20 ⎥⎦
2 ⎢⎣ S − p ⎥⎦
38. This type of spring incorporates a standard helical compression spring with two looped wire devices inserted through the inside of spring.
a) Helical compression spring
b) Drawbar spring c) Helical extension spring
d) Leaf spring
39. In a straight bevel gear, how do you call the angle between an element on the pitch cone and an element on the face cone?
a) Face angle
b) Pitch angle
c) Addendum angle
d) Dedendum angle
40. How do you call a large wood screw that is used to fasten machinery and equipment to a wooden base?
a) Lag screw
b) Wood screw
c) Log screw
d) Square screw
o
o
41. A journal bearing with angle of contact of the bushing or bearing with the journal is 180 or less, 120 is the common value.
a) Partial journal bearing
b) Full journal bearing
c) Clearance journal bearing
d) Concentric journal bearing
42. A journal bearing where the radius of the journal is less than the radius of the bushing or bearing.
a) Fitted journal bearing
b) Clearance journal bearing
c) Full journal bearing
43. It refers to the thickness of the space allowed for the lubricant that separates the parts having relative motion.
a) Radial clearance
b) Diametral clearance
c) Film thickness
d) Partial journal bearing
d) Clearance
44. A journal bearing where the radii of the journal and the bushing are equal; it must be a partial bearing and the journal must run eccentric with the
bushing in order to provide space for the lubricant.
a) Fitted journal bearing
b) Clearance journal bearing
c) Full journal bearing
d) Partial journal bearing
45. A partial journal bearing where the line of action of the load or bearing reaction is bisecting the arc of the partial bearing.
a) Partially loaded bearing
b) Eccentrically loaded bearing
c) Centrally loaded bearing
d) Fully loaded bearing
46. A journal bearing where the line of action of the load is passing to one side of the center.
a) Centrally loaded bearing
b) Eccentrically loaded or offset bearing
c) Fully loaded bearing
d) Partially loaded bearing
47. Which of the following threads are used for power screw?
5
MACHINE DESIGN/SHOP PRACTICE
a) Square thread, Acme thread, & Unified thread
b) Acme thread, Unified thread, & Buttress thread
c) Square thread, Unified thread, & Acme thread
d) Square thread, Acme thread, & Buttress Thread
48. A bearing lubrication obtained by introducing the lubricant, which is sometimes air or water, into the load-bearing area at a pressure high enough to
separate the surfaces with a relatively thick film of lubricant. This lubrication does not require motion of one surface relative to another.
a) Hydrodynamic lubrication
b) Hydrostatic lubrication
c) Boundary lubrication
d) Solid film lubrication
49. An externally threaded fastener intended to be used with nut is said to be a:
a) Bolt
b) Cap screw
c) Allen screw
d) Power screw
50. It is a lubrication condition where non-conformal surfaces are completely separated by lubricant film and no asperities are in contact.
a) Elastohydrodynamic lubrication
b) Solid film lubrication
c) Boundary lubrication
d) Hydrodynamic lubrication
51. Which of the following are the compositions of stainless steel 302?
a) 18 % chromium and 8 % nickel
b) 18 % nickel and 8 % chromium
c) 18 % chromium and 8 % phosphor bronze
d) 18 % bronze and 8 % vanadium
52. These springs are made from one or more flat strips of brass, bronze, steel or other materials loaded as cantilevers or simple beam.
a) Torsion springs
b) Leaf springs
c) Garter springs
d) Drawbar springs
53. This refers to the space between adjacent coils when the spring is compressed to its operating length.
a) Coil clearance
b) Pitch
c) Lead
d) Deflection
54. This material is the most popular alloy spring steel for conditions involving higher stresses than can be used with the high-carbon steels and for use
where fatigue resistance and long endurance are needed; this is also good for shock and impact loads.
a) Chrome silicon
b) Chrome vanadium
c) hard-drawn wire
d) Oil-tempered wire
55. For an American Standard Screw Threads, what does 6-32 UNC designate?
a) Size 6, 32 threads per inch, coarse thread
b) 6 inches basic diameter, 32 threads per inch, coarse thread
c) Size 6, 32 threads per inch, fine thread
d) 32 inches basic diameter, 6 threads per inch, coarse thread
Note: 6 stands for the designated size, 32 stands for the number of threads per inch, UNC stands for Coarse threads
56. It is a Grashof four-bar mechanism in which the shortest link is the frame or fixed link and the other two cranks completely rotate with their axes. How
do you call this Grashof four-bar mechanism?
a) Drag-link mechanism
b) Crank-rocker mechanism
c) Double-rocker mechanism
d) Triple-rocker mechanism
57.
“For a planar four-bar linkage, the sum of the shortest and longest lengths cannot be greater than the sum of the remaining two link lengths if there is
to be a continuous relative rotation between two members.” How do you call the preceding statement?
a) Grubler’s Law
b) Coriolli’s Law
c) Grashof’s Law
d) Freudentein’s Law
58. Which of the following is not true for an instant center or centro of planar linkages?
a) Centro is a point common to two bodies having the same velocity in each.
b) Centro is a point in one body about which another body does not rotate.
c) Centro is a point in one body about which another body actually turns.
d) Centro is a point in one body about which another body tends to turn.
59. This is the most common work holding device of a shaper machine with the base graduated in degrees that make it possible to swivel any angle. What
is this working device?
a) Shaper vise
b) Parallel bars and hold down bars
c) Lathe holder
d) Swivel head
60. This is a shaper operation, which is shaping the given stock and having the excess material remain with a tolerable allowance for finishing. How do you
call this operation?
a) Roughing
b) Finishing
c) Angular cutting
d) Contouring
61. How do you call a cutting tool that has two or more cutting edges as in drill presses and milling machine cutters?
a) Grinder
b) Single-point cutting tool
c) Multi-point cutting tool
d) Two point cutting tool
62. This is the trade name for a patented alloy made up chiefly of cobalt, chromium, and tungsten in varying proportions. What is this trade name?
a) Stellite
b) Carboloy
c) Stainless steel
d) Copper
63. It is called as the transformation of concepts and ideas into useful machinery. What is this?
a) Design
b) Synthesis
c) Analysis
d) Theorem
64. This is a combination of mechanisms and other components that transforms, transmits, or uses energy, load, or motion for a specific purpose. How do
yopu call this?
a) Mechanism
b) Engine
c) Machine
d) Linkage
65. It is defined as synergistic collection of machine elements; synergistic because as a design it represents an idea or concept greater than the sum of the
individual pats. What is this system?
a) System of mechanisms
b) Mechanical system
c) Design system
d) Expert system
66. It may be defined as the displacement per length produced in a solid and as the result of stress. How do you call this?
a) Deformation
b) Elongation
c) Strain
d) Stress
67. What is the combination of applied normal and shear stresses that produces maximum principal normal stress or minimum principal normal stress, with
a third principal stress between or equivalent to the extremes?
a) Principal shear stress
b) Principal normal stress
c) Maximum shear stress
d) Bending and shear stresses
68. How do you call a load that is applied transversely to longitudinal axis of member?
a) Combined loads
b) Concentrated load
c) Bending load
d) Distributed load
69. It is the capacity of a material to absorb energy when it is deformed elastically and then, upon unloading, to increase this energy. What is this capacity
of a material?
a) Resilience
b) Toughness
c) Rigidity
d) Ductility
70. How do you call the strain energy per unit volume required to stress a material from an unloaded state to the point of yielding?
a) Modulus of roughness
b) Modulus of elasticity
c) Modulus of rigidity
d) Modulus of resilience
71. What is the ability of the material to absorb energy up to fracture?
a) Toughness
b) Rigidity
c) Resilience
d) Stiffness
6
MACHINE DESIGN/SHOP PRACTICE
72. What is the other term for the Maximum-Shear-Stress Theory, as a failure prediction theory?
a) von Mises criterion
b) Tresca yield criterion
c) Coulomb-Mohr theory
d) Modified Mohr theory
73. It is a failure prediction theory, which states that a part subjected to any combination of loads will fail (by yielding or fracturing) whenever the maximum
shear stress exceeds a critical value. How do you call this failure prediction theory?
a) Distortion-energy theory
b) Maximum-shear-stress theory
c) Internal friction theory
d) Modified Mohr theory
74. This is a theory in cyclic and impact loading, which states that damage at any stress level, is proportional to number of cycles. What is this theory
commonly called?
a) Miner’s Rule
b) Paris Power Law
c) Goodman Rule
d) Manson-Coffin Relationship
75. This is a lubrication where the load-carrying surfaces of the bearing are separated by a relatively thick film of lubricant, so as to prevent metal-to-metal
contact; and where the stability of the film can be explained by the laws of fluid mechanics. How do you call this type of lubrication?
a) Hydrostatic lubrication
b) Hydrodynamic lubrication
c) Elastohydrodynamic lubrication
d) Boundary lubrication
76. How do call the speed at which a rotating shaft becomes dynamically unstable?
a) Normal speed
b) Variable speed
c) Critical speed
77. How do you call a ball bearing with race containing pronounced groove for rolling elements?
a) Crown bearing
b) Conrad bearing
c) Angular-contact bearing
d) Average speed
d) Cylindrical bearing
78. This is a machining process for producing internal straight cylindrical surface or profiles, with process characteristics and tooling similar to those for
turning operations. What is this machining process?
a) Boring
b) Drilling
c) Reaming
d) Milling
79. What is a set of specification for parts, materials, or processes intended to achieve uniformity, efficiency, and a specified quality?
a) Code
b) Standard
c) Law
d) Theorem
80. This is a set of specifications for the analysis, design, manufacture, and construction of something; the purpose of which is to achieve a specified
degree of safety, efficiency, and performance or quality. How do you call this set of specifications?
a) Code
b) Standard
c) Law
d) Theorem
81. How do call the size to which limits or deviations is assigned and is the same for both members of the fit; it is the exact theoretical size?
a) Nominal size
b) Basic size
c) Maximum size
d) Minimum size
82. What is the algebraic difference between a size and the corresponding basic size?
a) Tolerance
b) Allowance
c) Deviation
d) Limit
83. What is the difference between the maximum and minimum size limits of a part?
a) Allowance
b) Tolerance
c) Deviation
d) Basic size
84. What are the stated maximum and minimum dimensions?
a) Tolerances
b) Limits
c) Nominal sizes
d) Basic sizes
85. This is a general term that refers to the mating of cylindrical parts such as bolt or a hole; it is used only when the internal member is smaller that the
external member. How do you call this?
a) Clearance
b) Interference
c) Allowance
d) Tolerance
86. What is the opposite of clearance, for mating cylindrical parts in which the internal member is larger than the external member?
a) Clearance
b) Allowance
c) Tolerance
d) Interference
87. These are compounds of metallic elements, most frequently oxides, nitrides, and carbides.
a) Plastics
b) Polymers
c) Ceramics
d) Alloy
88. What do you call a material having different properties in all directions at point in solid?
a) Isotropic material
b) Anisotropic material
c) Orthotropic material
d) Ceramic material
89. This is a principle or method that a deflection at any point in bar is equal to sum of deflections caused by each load acting separately. How do you call
this method or principle?
a) Summation Method
b) Method of balancing
c) Method of superposition
d) Shear and Moment diagram method
90. This is the accepted standard wire rope with the wires twisted in one direction to from strands and the strands twisted in opposite direction to form a
rope. How do you call this wire rope?
a) Improved plow steel wire rope
b) Regular lang lay wire rope
c) Mild plow steel wire rope d) Long lay wire rope
91. What is a form of correction that develops on highly localized areas on a metal surface?
a) Crevice
b) Erosion
c) Galvanic
d) Apitting
92. How do you call the corrosion of iron-base-alloys?
a) Rusting
b) Crazing
c) Chalking
d) Fritting
93. Which of the following is the allowable stress that is generally used in practice for main transmitting shafts?
a) 8 500 psi
b) 4 000 psi
c) 6 000 psi
d) 6 500 psi
94. What is an equation used to determine the first critical speed of the shaft that overestimates frequency?
a) Soderberg Equation
b) Rayleigh Equation
c) Dunkerly Equation
d) Euler Equation
95. This key allows the hub to move along the shaft but prevents the rotation of the shaft. How do you call this key?
a) Woodruff key
b) Feather key
c) Gibs key
d) Square key
96. How do you call the ratio of mean diameter of coil and the coil diameter of a spring?
a) Wahl number
b) Diameter ratio
c) Spring index
d) Lead angle
97. For ACME thread the pressure angle normal to the thread is equal to:
o
o
o
o
b) 14.5
c) 13.5
d) 34
a) 12.5
98. It is a low cost spring material, suitable where service is not severe and dimensional precision is not needed. How do you call this spring material?
a) Hard drawn wire
b) helical spring wire
c) Stainless steel
d) helical tension spring wire
99. How do you call a spring material that is hard drawn (80 % reduction) but made up of high-grade steel?
a) Music wire
b) Oil tempered wire
c) Song wire
d) Chromium-silicon wire
100. It is a design approach where no catastrophic loss can occur as a result of a component failure. What is this design approach?
a) Fail-safe design approach
b) Fault free analysis approach
c) Manifest danger approach
d)
Redundancy
approach
7
MACHINE DESIGN/SHOP PRACTICE
Note: The following questions are for your reading and Familiarization
SET A
101. In a lathe machine, how do you call the diameter of the largest workpiece that can be rotated in a chuck or between centers without hitting the bed?
a) Chuck diameter
b) Swing c) Distance between centers d) Spindle diameter
102. How do you call a phenomenon when two touching surfaces have a high contact pressure and when these surfaces have minute relative motion?
a) Pre-stressing
b) Friction
c) Carving
d) Fretting
103. What is this part of headstock of a lathe machine used to transmit power from the spindle?
a) Motor
b) Back gear
c) Headstock spindle
d) Switch
104. When a hot part is cooled suddenly by quenching, there is momentarily a high temperature gradient that induces a stress gradient. Some metal parts
under certain conditions crack as a result. What is this phenomenon?
a) Thermal-shock failure
b) Thermal fatigue c) Honing
d) Quenching
105. When a hot part is cooled suddenly by quenching, there is momentarily a high temperature gradient that induces a stress gradient. Some metal parts
under certain conditions crack as a result. How do you call this phenomenon?
a) Thermal-shock failure
b) Thermal fatigue c) Honing
d) Quenching
106. It is the condition of a machine element when it is completely inoperable, cannot perform its intended function adequately, or is unreliable for continued
safe use. What do you call this condition?
a) Fail-safe condition
b) Failure condition
c) Critical condition
d) Salvage condition
107. How do you call a statistical data used to identify the most likely failure modes?
a) Finite element analysis
b) Fault free analysis
c) Failure analysis
d) Random analysis
108. It is a computational method used for solving complex shapes, such as those found in machinery; replaces the complex shape with a set of simple
elements interconnected at a finite set of a specific purpose. What is this computational method?
a) Finite element analysis
b) Numerical method of analysis
c) Fault free analysis
d) Synthesis
109. It is a design approach where needed service is made apparent before catastrophic failure. How do you call this?
a) Manifest danger design approach
b) Machine element function approach
c) Failure analysis
d) Random analysis
110. It is a beam where one end is fixed and other end is free. How do you call this beam?
a) Cantilever beam
b) Continues beam c) Overhanging beam
d) Long beam
111. It is a method used to graphically visualize state of stress acting in different planes passing through a given point. What is this?
a) Mohr’s circle
b) Soderberg Criterion
c) Goodmann’s method
d) Gerber’s line criterion
112. This minimum distance is measured between the non-driving side of a tooth and the adjacent side of the mating tooth. It is the amount by which the
width of a tooth space exceeds the thickness of the engaging tooth measured on the pitch circle. What is this distance?
a) Circular pitch
b) Whole depth
c) Backlash
d) Space width
113. It is an arc of the pitch circle of a spur gear through which a tooth travels from the point of contact with the mating tooth to the pitch point. What is this
arc?
a) Arc of action
b) Arc of approach c) Arc of recess
d) Involute curve
114. What is the intersection of the elements making up the pitch cone?
a) Pitch cone
b) Cone distance
c) Apex of pitch cone
d) Root cone
115. What do you call a type of bolt threaded on both ends and can be used where a through bolt is impossible?
a) Coupling bolt
b) Machine bolt
c) Stud bolt
d) Carriage bolt
116. To avoid excessive wear rate, what is the recommended limiting pressure for 6 x 19 rope for cast iron?
a) 200 psi
b) 400 psi
c) 300 psi
d) 500 psi
117. How do you call a type of welding where the arc is covered with a welding composition and a bare electrode wire is fed automatically?
a) Resistance welding
b) Submerged arc welding c) Induction welding d) Spot welding
118. It is a kind of wear that occurs because of fatigue failure of the surface materials as a result of high contact stresses. What do you call this?
a) Slotting
b) Pitting
c) Involuting
d) Curving
119. It is caused by foreign matters, such as grit or metal particles, or by a failure of the oil film at low speed. How do yopu call this?
a) Auction
b) Scoring
c) Abrasion
d) Corrosion
120. It occurs when the oil films fails, but in this case, the load and speed are so high that the metal is melted and the metal is smeared down the profile.
What is this?
a) Abrasion
b) Corrosion
c) Spalling
d) Scoring
121. In gearing system, it is the advance of the tooth in the face width divided by circular pitch. What do you call this?
a) Face contact ratio
b) Speed ratio
c) Profile ratio
d) Advance ratio
122. When the pitch line speed is above 8000 fpm, the teeth should be _____.
a) Ground after hardening
b) Should be cooled in air
c) Should not be quenched after hardening`
d) none of these
123. How do you call a spring material that is hard drawn (80 % reduction) but made up of high-grade steel?
a) Music wire
b) Oil tempered wire
c) Song wire
d) Chromium-silicon wire
124. It is a spring wire with good quality for impact loads and moderately high temperatures. What is this spring material?
a) Hard drawn spring wire
b) helical spring wire
c) Chromium-silicon
d) Helical tension wire
125. It is a type of coil spring where the helical coil is wrapped into a circle forming an annular ring. How do you call this spring?
a) Volute spring
b) Motor spring
c) Hair spring
d) Garter spring
126. It is a type of spring where thin flat strip wound up on itself as a plane spiral, usually anchored at the inside end. What do you call this spring?
a) Volute spring
b) Motor spring
c) Hair spring
d) Garter spring
127. What do you call a ratio of the length of the column and the radius of gyration of the cross-sectional area about the centroidal axis?
a) Power factor
b) Contact ratio
d) Constant ratio
d) Slenderness ratio
128. A screw that requires a positive torque to lower the load, or to loosen the screw if it has been turned tight against a resistance. How do you call this
screw?
a) Power screw
b) Self screw
c) Lock screw
d) Self-locking screw
129. What is the other term used for Kennedy key?
a) Tangential key b) Normal key
c) Saddle key
d) Rollpin key
130. Which of the following device used to measure the speed accurately?
a) Dial gage
b) Dial indicator
c) Speedometer
d) Tachometer
8
MACHINE DESIGN/SHOP PRACTICE
131. When the hole is smaller than the shaft, it will take pressure to put the parts together. The allowance is said to be negative and is termed as:
a) Interference of metal
b) Negative allowance
c) Negative tolerance
d) Negative fits
132. When two elastic bodies collide, which of the following laws can be used to solve for the resulting velocity?
a) Avogadro’s law
b) Conservation of momentum and conservation of energy
c) Dalton’s law of partial pressure
c) Conservation of energy
133. It is a science of motion that can be solved in terms of scalar or vector algebra. How do you cal this science?
a) Kinematics
b) Dynamics of machine
c) Engineering mechanics
d) Strength of materials
134. What is a screw fastener with a nut on it?
a) Bolt
b) Rivet
c) Fastener
d) Square screw
135. It is a type of bolt distinguished by a short portion of shank underneath the head, being square or finned or ribbed. What is this bolt?
a) Coupling bolt
b) Machine bolt
c) Stud bolt
d) Carriage bolt
136. Non-ferrous filler metal is melted into grooves or as fillet on the mother metal; the base metal is not melted. This is commonly used for joining iron
based machine parts or in repair works of some materials. It is called:
a) Spot welding
b) Braze welding
c) Brazing
d) Gas welding
137. It is advised that in rubber belts applications/mountings, it should have an initial tension of:
a) 18 to 24 lb/inch-ply
b) 15 to 20 lb/inch-ply
c) 12 to 15 lb/inch-ply
138. Normal stress relieving temperature for cast iron:
o
o
o
b) 400 to 500 F
c) 300 to 550 F
a) 200 to 350 F
d) 10 lb/inch-ply
o
d) 450 to 550 F
139. A flexible coupling consists of essentially of two chain sprockets connected with short continuous length of roller or silent chains.
a) Chain coupling
b) Oldham coupling c) Flanged coupling
d) Universal joint
140. A material of construction (only developed commercially in the late 1940’s concurrently with zirconium) offers the unique combination of wide ranging
corrosion resistance, low density, and high strength.
a) Titanium
b) Tungsten
c) Vanadium
d) Molybdenum
SET B
1. As one example, the ASME for riveted joints permits the design surface compressive stress to be about __________ higher than the design stress.
a) 50 %
b) 40 %
c) 60 %
d) 70 %
2. When tested in compression, ductile materials usually exhibit ________ characteristics up to the yield strength as they do when tested in tension.
a) The same
b) Less than
c) More than
d) Approximately the same
3.
4.
5.
6.
7.
8.
Helical gears mounted on non-parallel shafts are called
a) Open gear
b) Crossed helical gear
c) Closed helical gear
d) Herringbone
For a symmetrical cross-sectional beam, what is the value of flexural stress when the vertical shear stress is at maximum?
a) Infinity
b) Maximum
c) Zero
d) Minimum
Is the distance between the teeth measured on the pitch surface along a normal to the helix.
a) Lead
b) Lead angle
c) Pitch
d) Normal circular pitch
The hardness of helical and herring bone teeth cut after heat treatment eill generally fall between the limits of
a) 210 and 300 Brinell
b) 147 to 300 Brinell c) 230 and 320 Brinell
d) 220 and 320 Brinell
The typical helix angle ranges form ____ to _____.
o
o
o
o
o
o
b) 10 to 12
c) 14 to 20
a) 12 to 15
Is the advance of the tooth in the face width divided by circular pitch.
a) Face contact ratio
b) Speed ratio
c) Profile ratio
o
o
d) 15 to 25
d) Advance ratio
o
To eliminate fouling, let the minimum differences in tooth numbers between the internal gear and pinion, be ____ for 14.5 involute full-depth.
a) 10 teeth
b) 14 teeth
c) 12 teeth
d) 16 teeth
10. The loss per pair of spur, helical, or bevel gears in an ordinary train should no exceed ______.
a) 4%
b) 2%
c) 6%
d) 3%
9.
11. If the atoms which compose the molecules of a pure chemical substance are not all of the same kind, the substance is known as:
a) Compound substance
b) Elementary substance
c) Pure substance
d) Mixture substance
12. These non-destructive test methods employ high-frequency mechanical vibrational energy to detect and locate structural discontinuities or differences
and to measure thickness of a variety of materials. How do you call these test methods?
a) Ultrasonic test methods
b) Radiographic test methods
c) Eddy current nondestructive tests
d) Microwave test methods
13. If the molecules or atoms of which any given material is composed are all exactly alike, the material is said to be as a:
a) Compound substance
b) Simple substance
c) Mixture substance
d) Pure substance
14. If the atoms which compose the molecules of any pure substances are all of the same kind, the substance is called as:
a) An elementary substance
b) A compound substance
c) A pure substance
d) A simple substance
15. The strength of non-ferrous alloys is maximum at room temperature while that of ferrous metal has a maximum strength at:
o
o
o
o
b) 450 F
c) 1200 F
d) 350 F
a) 400 F
16. When the chromium content is increased to about 11 percent in an iron-chromium alloy, the resulting material is generally classified as what material?
a) Stainless steel
b) Carbon Steel
c) Wrought steel
d) Cast Steel
17. How do you call those tests that determine the usefulness, serviceability, or quality of a part or material without limiting its usefulness? These tests are
used in machinery maintenance to avoid costly unscheduled loss of service due to fatigue or wear; and they are used in manufacturing to ensure
product quality and minimize costs.
9
MACHINE DESIGN/SHOP PRACTICE
a) Nondestructive tests
b) Destructive tests
c) Hydro tests
d) Penetrant tests
18. The lack of backlash in a spur gear design/operation may result to:
a) Overloading
b) Jamming
c) Overheating
d) Both a, b, & c
19. Splines are used when:
a) The power to be transmitted is high
b) The torque is high
c) The speed is high
d) Axial relative motion between shaft and hub is necessary
20. Which of the following contains chromium?
a) SAE 2340
b) SAE 4230
21. Which of the following is not a heat treatment process?
a) Sintering
b) Annealing
c) SAE 5240
d) SAE 1230
c) Hardening
d) Tempering
22. An instrument used to analyse the compositions of metals:
a) Spectrometer
b) Radiometer
c) Profilometer
d) Ultimate analyser
23. Creep is the term used in referring to the:
a) Elongation before yield point
b) Maximum stress of brittle materials
c) Fatigue limit of ductile materials
d) Continuous increase in the strain, or deformation, of any material subjected to stress
24. The function of the clutch in the machine tools is:
a) Lowering the drive speed
b) To disconnect or connect the shaft at will the drive
c) Alignment of drive shaft
d) To insure that two shafts line up at high speed
25. Should two equal and opposite collinear forces is added to the forces already in equilibrium, which of the following statements is true?
a) Unbalanced moment is maintained
b) Equilibrium is maintained
c) Equilibrium is distributed
c) It creates an unbalanced situation
26. Also called as eccentricity loaded bearing:
a) Full bearing
b) Offset bearing
c) Partial bearing
27. The moment of inertia of a rectangle whose base is “b” and height “h” about its base:
a)
bh 3
4
b)
bh 3
12
c)
bh 3
24
d) Fitted bearing
d)
bh 3
3
28. Opposite directional forces equal in magnitude and parallel is called as:
a) Non coplanar
b) Couple
c) Centro
d) Coplanar
29. The hardness of helical and herring bone teeth cut after heat treatment eill generally fall between the limits of
a) 210 and 300 Brinell
b) 147 to 300 Brinell c) 230 and 320 Brinell
d) 220 and 320 Brinell
30. The typical helix angle ranges form ____ to _____.
o
o
o
o
b) 10 to 12
a) 12 to 15
31. Which of the following is a unit of energy?
a) Ft-lb
b) Hp
32. Steel containing large amounts of mild nickel and chromium:
a) Carbon steel
b) Alloy steel
o
c) 14 to 20
o
o
o
d) 15 to 25
c) Btu/hr
d) Watt
c) Stainless steel
d) Cast steel
33. Eccentricity loaded bearing is also called as:
a) Hydrostatic bearing
b) Split bearing
c) Partial bearing
d) Offset bearing
34. In the selection of wire rope, Lang lay means the wires and strands are twisted:
a) In the same direction b) In any direction c) In opposite directions
d) In along direction
35. Continuous stretching under load even if the stress is less than the yield point:
a) Plasticity
b) Creep
c) Elasticity
36. The product of the mass and the linear velocity of a body:
a) Angular impulse
b) Angular momentum
c) Linear impulse
d) Ductility
d) Linear momentum
37. The length of the hub should not be made lesser than the face width of the gear. Hub lengths usually vary from 1.25D to 2D, where D is the shaft
diameter. The reasonable diameter of steel hub should be:
a) 2D
b) 1.55D
c) 1.8D
d) 1.20D
38. It is the plane perpendicular to the axial plane and to the pitch plane. In gear the parallel axes, and the plane rotation coincide.
a) Tangent plane
b) Straight plane
c) Transverse
d) Reference plane
39. Type of bolt commonly used in the construction that is threaded at both ends.
a) Stud bolt
b) Hex bolt
c) ACME thread bolt
d) Square threaded bolt
40. The most known lubricants being utilized in whatever category of load and speed are oil, air, grease and dry lubricants like:
a) Bronze
b) Silicon
c) Lead
d) Graphite
41. Imaginary formed by the intersection of the flanks of a thread when extended is called ________ beyond the root.
a) Sharp crest
b) Root apex
c) Sharp root
d) Crest line
42. A hydrostatic bearing is one which:
a) Lube oil is supplied under pressure
b) There is no lube
c) Lube oil is not pressurized
d) Bearing is slightly loaded
43. An ideal herringbone gear helix angle is in the range of:
o
o
o
o
o
o
o
o
b) 35 to 50
c) 25 to 30
d) 15 to 20
a) 30 to 45
10
MACHINE DESIGN/SHOP PRACTICE
44. A machine member which is used to connect shafts and to disconnect them at will:
a) Coupling
b) Clutch
c) Collar
d) Universal joint
45. Poisson’s ratio is the ratio of:
a) Lateral stress to longitudinal stress
b) Shear stress to shear strain
c) Compressive stress to tensile stress
d) Lateral strain to longitudinal strain
46. In a chain drive design for large speed reduction, it is preferable to use a double reduction of compound type of transmission instead of single two
sprockets transmission. Drives should be so designed that the angle between two tight chain strand does not exceed:
o
o
o
o
b) 55
c) 60
d) 90
a) 45
47. The product of the mass and the linear velocity of a body is called as:
a) Linear impulse
b) Linear momentum
c) Couple
d) Vector
48. Bearing surface that completely surrounds the journal is also called as:
a) Offset bearing
b) Centrally loaded bearing
c) Full bearing
49. The ratio of the pitch diameter in inches to the number of teeth.
a) Diametral pitch
b) Circular pitch
c) Module
d) Babbitt bearing
d) English Module
50. Molybdenum-chromium-nickel steel designation:
a) SAE 48xx
b) SAE 43xx
c) SAE 56xx
d) SAE46xx
51. Arc of the pitch circle through which a tooth travels from the point of contact with the mating tooth to the pitch point of a gear.
a) Arc of recess
b) Arc of action
c) Arc of approach d) Arc of relief
52. Which of the following is not pertaining to the joining of metals?
a) Welding
b) Soldering
53. Killed steel is always associated with:
a) Silicon
b) Manganese
c) Casting
d) Brazing
c) Phosphorous
d) Sulfur
54. What is the usual ratio of water to soluble oil used as cutting fluid?
a) 50 % water to 50 % oil b) 2 water to 1 oil
c) 3 water to 1 oil
55. Which of the following is not pertaining to the joining of metals?
a) Welding
b) Soldering
c) Casting
56. Killed steel is always associated with:
a) Silicon
b) Manganese
c) Phosphorous
57. What is the usual ratio of water to soluble oil used as cutting fluid?
a) 50 % water to 50 % oil b) 2 water to 1 oil
c) 3 water to 1 oil
d) 4 to 80 water to 1 oil
d) Brazing
d) Sulfur
d) 4 to 80 water to 1 oil
58. Statement that a given body is in static equilibrium means that the body cannot:
a) Have any type of motion
b) Be acted upon by more than one force
c) Undergo any displacement
d) Have any acceleration
59. Ordinary steel begins to loose strength and elasticity significantly at about:
o
o
o
o
b) 800 to 900 F
c) 750 to 850 F
d) 600 to 700 F
a) 900 to 1000 F
60. Clearance to a new boiler installation to the existing or old plant building should follow a minimum clearance of ________ between top of the boiler
proper and the ceiling as stated in the PSME Code.
a) 2000 mm (max)
b) 1000 mm (max)
c) 2130 mm (max)
d) 2150 mm (max)
61. For a high corrosion resistant stainless steel, what minimum chromium content is required?
a) 8 %
b) 4.3 %
c) 1.1 %
d) 5.8 %
62. Name the type of chuck commonly used for holding workpiece in a lathe operation. Example: 3-jaw universal chuck, 4-jaw independent chuck.
a) Magnetic jaw chuck
b) 2-jaw independent chuck c) 8-jaw universal
d) Combination
63. V-belt operate efficiently at speed of about:
a) 4500 fpm
b) 4400 fpm
c) 4200 fpm
d) 3600 fpm
64. What type of gear is used for high speed operation?
a) Helical
b) Spur
c) Bevel
d) Worm
65. In a pair of gears, it is the plane perpendicular to the axial plane and tangent to the pitch surface.
a) Pitch
b) Pitch plane
c) Pitch circle
d) Pitch point
66. Normal stress relieving temperature for cast iron:
o
o
o
b) 400 to 500 F
c) 300 to 550 F
a) 200 to 350 F
67. Most effective alloying element for reducing brittleness of steel at very low temperature:
a) Manganese
b) Molybdenum
c) Silicon
68. Deals only with the motion of bodies without reference to the forces that cause them:
a) Dynamics
b) Kinetics
c) Statics
69. The property that characterizes a material ability to be drawn onto a wire:
a) Ductility
b) Thermal conductivity
c) Tensile strength
o
d) 450 to 550 F
d) Nickel
d) Kinematics
d) Endurance limit
70. One of the causes of spur gear tooth breakage is the unbalanced load on one end of the tooth that results in higher stresses than when the load is
evenly distributed. To minimize this problem, the face width “b” should not be greater than the thickness (or pitch) of the tooth. In the absence of test
values, the following can be a guide:
b) 2pd < b < 4 pd
c) 2.5pd < b < 4pd
d) 2pc < b < 4 pc
a) 2.5pc < b < 4pc
71. The three moment equation may be used to analyse:
a) Tapered column
b) Continuous beam
c) Composite beam
d) Axially end loaded beam
11
MACHINE DESIGN/SHOP PRACTICE
72. What is the common shop practice ti prevent solder from running away from surface to be joined?
a) Surround the work with clay
b) Introduce around the work rolled wet cloth
c) Put asbestos sheathing around the work
d) All of these
73. Non-ferrous filler metal is melted into grooves or as fillet on the mother metal; the base metal is not melted. This is commonly used for joining iron
based machine parts or in repair works of some materials. It is called:
a) Spot welding
b) Braze welding
c) Brazing
d) Gas welding
74. It is advised that in rubber belts applications/mountings, it should have an initial tension of:
a) 18 to 24 lb/inch-ply
b) 15 to 20 lb/inch-ply
c) 12 to 15 lb/inch-ply
d) 10 lb/inch-ply
75. Hypoid gear is a special type of gear like:
a) Worm gear
b) Spur gear
c) Herringbone gear
d) Bevel gear
76. The considered maximum safe center distance of sprockets because very long center distance causes catenary tension in the chain.
a) 70 pitches
b) 80 pitches
c) 60 pitches
d) 50 pitches
77. Cold working of steel plates make the metal:
a) Tougher
b) More ductile
c) Harder
d) More malleable
78. Recommended best cutting angle of drill for work on steel or cast iron is:
a) 48 degree
b) 63 degrees
c) 59 degrees
d) 50 degrees
79. In shear pin or breaking pin design, we may use the data experienced by link belt from 1/8 inch to 1 inch pins and the breaking stress is:
a) 40 ksi
b) 55 ksi
c) 50 ksi
d) 48 ksi
80. All are associated with the grade of steel except:
a) SAE 43xx
b) SAE 13xx
c) SAE 10xx
81. A property of material that relates the lateral strain to the longitudinal strain:
a) Stress
b) Strain
c) Poisson’s ratio
d) SAE 74xx
d) Strength
82. The maximum stress to which a material may be subjected before failure occurs.
a) Ultimate strength
b) Ultimate stress
c) Endurance limit
d) Tensile stress
83. The smallest area at the point of rupture of a tensile specimen divided by the original area is called:
a) Percentage elongation
b) Izod test
c) Charpy test
d) Percentage reduction of area
84. The product of the resultant of all forces acting on a body and the time that the resultant acts:
a) Angular impulse
b) Angular momentum
c) Linear Impulse
85. Which of the following is not a structural class of steel?
a) Low carbon steel
b) Tool and die steel
c) High chrome alloy steel
d) High strength low allow steel
86. Poisson’s ratio is the ratio of which of the following?
a) Shear strain to compressive strain
c) Lateral strain to longitudinal strain
87. Metal that assists lubrication or lubrication in itself:
a) Zinc
b) Antimony
d) Lead
d) Linear momentum
b) Elastic limit to compressive strain
d) Elastic limit to proportional limit
c) Babbit
88. A mechanism that usually do the indexing in a machine tool:
a) Universal chuck
b) Slotter
c) Dividing head
d) Indexing
89. It equalizes the energy exerted and the work done, thus, preventing excessive or sudden changes of speed:
a) Flywheel
b) Balance wheel
c) Flywheel pulley
d) All of these
90. It is a spring wire with good quality for impact loads and moderately high temperatures. What is this spring material?
a) Hard drawn spring wire
b) helical spring wire
c) Chromium-silicon
d) Helical tension wire
91. How do you call a load that is applied transversely to longitudinal axis of member?
a) Combined loads
b) Concentrated load
c) Bending load
d) Distributed load
12
MACHINE DESIGN/SHOP PRACTICE
JCSF ENGINEERING REVIEW CENTER
2nd Floor Santos‐Causing Building, National Highway
Halang, City of Calamba, Laguna
MACHINE DESIGN AND SHOP PRACTICE (Refreshers Trivia # 3)
Prepared by: Jose R. Francisco, PME
September 2012
MULTIPLE CHOICE QUESTIONS
Select the best answer from each of the following questions. On the answer sheet provided, shade the box that corresponds to your choice. Strictly no
erasures allowed.
1.
What is the stress area of a 1-inch diameter bolt that has a TPI (Threads per inch) of 8?
2
2
2
b) 0.626 in
c) 0.443 in
a) 0.565 in
Solution: A = π [D − 0.9743p]2 : → p = 1 :
s
4
2.
TPI
→ A s = 0.606in 2
A simple band brake, installed on a 500mm brake drum, is used to absorb a torque of 250 N-m. If the coefficient of friction and the contact angle
between the band and drum are 0.2 and 180º, respectively, and that the length of the brake arm is twice the drum diameter, determine the minimum
braking force applied at the free end of the brake arm.
a) 721.5 N
b) 752.1 N
c) 275.1 N
d) 572.1 N
F2 (a )
Solution: F1 = e fθ = 1.874 : → F
: a = D : → L = 2D
b min =
DA
D
= B :
sin α sin β
1
2 .5
=
: β = 58.77 o :
sin 20 o sin β
F1
=e
F
⎡
⎢ fθ
⎢
⎢ sin 1 β
2
⎣⎢
⎤
⎥
⎥
⎥
⎦⎥
= 15 . 044 :
T =
T =
( F1 − F2 ) D
: F1 = 268 . 5 N
2
A shaft is simultaneously loaded with a torque of 900 N-m and a bending load of 4000N applied at the center of its 500mm span. Considering a
maximum shear design stress of 60 MPa, determine the shaft diameter.
a) 38.44 mm
b) 34.83 mm
c) 44.38 mm
d) 84.33 mm
→ Te = T 2 + M 2
→
16Te
πD 3
= Ssd
→ D = 44.38mm
A 20-kW motor, running at 1200 rpm, drives a 400 mm diameter pulley at a belt tension ratio of 2.4. If the belt’s tight side tension is only 1200 N,
determine the transmission efficiency.
a) 87.97 %
b) 84.58 %
c) 85.66 %
d) 86.55 %
Solution: η =
8.
→ FR = Ft2 + Fr2 = 580.2 N
θ = α + β = 78.77 deg .
Power
x 9 . 549 x 10 6 :
n
Solution: T = 900,000 N − mm : → M = FL = 500,000 N − mm
4
7.
→ Fr = Ft tan φ = 198.6 N :
A V-belt drive uses a 152.4 mm sheave with a groove angle of 36º. The sheave is coupled to a 2 kW motor running at 1000 rpm. Considering a belt
coefficient of friction of 0.3 and a contact angle of 160º, determine the maximum tension on the V-belt.
a) 586.7 N
b) 752.8 N
c) 268.5 N
d) 685.2 N
Solution:
6.
→ Ft = 546.7 N
Two bevel gears at a gear ratio of 2.5:1 are used for a certain drive. If the pinion has a cone angle of 20º, determine the shaft angle of the gears.
a) 75.85º
b) 69.23º
c) 84.23º
d) 78.77º
Solution:
5.
2T
F2
D
=
=
= 572.1N
2 2(1.874 − 1)
Calculate the resultant bending load on a shaft that carries a 200mm-diameter, 20º full depth pinion. The pinion transmits 10 kW at 1750 rpm.
a) 258.0 N
b) 685.0 N
c) 850.2 N
d) 580.2 N
⎡ 10
⎤
2⎢
x 9.549 x10 6 ⎥
2
T
1750
⎣
⎦:
Solution: Ft =
=
D
200
4.
→ Fb min
L
F2
3.
2
d) 0.606 in
Poutput
Pinput
1200 ⎞
⎛ 1200 π ⎞ ⎛ 0.40 ⎞ ⎛
⎛ π n ⎞⎛ D ⎞
Tout (π n ) ⎛ π n ⎞ ⎛ D ⎞ F
⎟
⎟ ⎜1200 −
⎟⎜
⎟ ⎜ ⎟ (F1 − F2 ) ⎜
⎟ ⎜ ⎟ net ⎜
⎜
30 ⎠ ⎝ 2 ⎠
30 ⎠ ⎝ 2 ⎠
30 ⎠ ⎝ 2 ⎠ ⎝
2.4 ⎠
30
= 0.8797
=⎝
=⎝
=
=⎝
Pinput
Pinput
Pinput
20 000
A cylindrical vessel has an inside diameter of 40 inches, is subjected to a pressure of 2000 psi, and is constructed with a joint efficiency of 90%. Find
the thickness if the allowable stress of the steel plate used is 10,000 psi.
a) 4.44 in
b) 5.07 in.
c) 6.58 in.
d) 8.56 in
S
Solution: S = p D = y = S
t
d
2tEj
N
→ t = 4.44 in.
but
t
> 0.1
D
→ thick − walled
1
MACHINE DESIGN/SHOP PRACTICE
t=
9.
D ⎡ S+ p ⎤
− 1⎥
⎢
2 ⎢⎣ S − p ⎥⎦
→ S = 0.9x10,000 = 9000 : → t = 5.07in.
Find the maximum permissible concentrated bending load that may be carried by a simply-supported shaft of 2-ft span of 2-in. diameter if the allowable
flexural stress is 6,000 psi.
a) 854.7 lb
b) 485.7 lb
c) 587.4 lb
d) 785.4 lb
Solution: Bending moment is maximum if F is applied at mid span.
σ=
Mc 32M
=
I
πD 3
→ M=
FL
4
32(F)(24)
= 6000
4π(2 3 )
→
→ F = 785.4lb.
10. A bar of rectangular section is made of AISI C1020 steel (Su = 65,000 psi), and is subjected to a tensile load of 8 tons. If the width of the bar is 1.5
times the thickness, find the bar dimensions if the factor of utilization is 0.25 based upon the ultimate strength.
a) 0.5” x 0.75”
b) 1” x 1.5”
c) 1.5” x 2.25”
d) 0.81” x 1.22”
Solution: Factor of Utilization =
1
Factor of Safety
s=
S
F
8 x 2000
= u = ( U.FxS u ) :
= 0.25 x 65000 : → b = 0.81in.
N
1 .5 b 2
1 .5 b 2
and b x h = 0.81” x 1.22”
11. A low carbon steel sheet 3/8 in. thick, lined with aluminum 1/8 in. thick, is used to form a connecting rod. Steel has a modulus of elasticity of 30 x 10
6
psi, while aluminum of 10.3 x 10 psi. If the aluminum has a tensile stress of 10,000 psi, what is the corresponding stress of the steel sheet?
a) 12,961 psi
b) 96,122 psi
c) 29,126 psi
d) 26,191 psi
Solution: σ = E ε: With constant strain ε, σAL/EAL = σST/EST.
6
Thus, σST = (30/10.3) x (10,000) = 29,126 psi.
12. A 25 mm square threaded screw (20 mm root diameter, pitch = 5 mm), is 380 mm long between the nut and the collar. The axial load is 25,000 N and
the torque in the screw between the nut and the collar, is 110 N-m. Using end fixity factor of unity and neglecting the threads, determine the factor of
safety if steel with a yield point in tension of 345 Mpa is used. Consider the modulus of elasticity for steel to be 200 GPa.
a) 2.41
b) 2.04
c) 1.34
d) 1.96
SR =
Solution:
L e n e L n e L 380(4)
=
=
=
= 76 <120
D
20
k
I
4
A
→ the column is short
n e − end fixity factor, k − radius of gyration, D − diameter of member, L − actual length
the equivalent compressive stress for the column, by J.B. Johnson equation : Seq
The stress due to torsion is then,
Ss =
16T
= 70 MPa
πD 3
Using the maximum shear stress theory: S
S max =
Then the factor of safety is
N=
⎡
⎤
⎢
⎥
⎥
F⎢
1
= ⎢
⎥ = 106.44Mpa
A ⎢ S y (SR ) 2 ⎥
E⎥
⎢1 −
4n e π 2
⎥⎦
⎣⎢
0.5S y
SS max
(
Seq
2
) 2 + SS
2
= 87.93Mpa
= 1.96
13. A 9 cm square bar is to be held firmly at one end and to support a load of 2000 kg at the other end. The bar is to be 1.5 m long, and is to be made from
steel with yield strength of 500 MPa. What factor of safety is used in the design if the stress concentration factor is 1.3?
a) 2.34
b) 3.45
c) 2.67
d) 1.59
Solution: SY = K t Mc
N
I
Where, M = FL = 29430000 N ⋅ mm
then N =
Sy I
K t Mc
I=
a4
= 5467500mm4
12
c = a / 2 = 45mm
thus : N = 1.59
14. A round bar made from SAE 1025 low carbon steel is to support a direct tensile load of 222.449 kN. Using a factor of safety of 4 and assuming that the
stress concentration factor is 1.45, what is the required outside diameter in mm of the member if the ratio of the inside and outside diameter is 0.75?
For the material, the yield strength is 276MPa.
a) 283.34
b) 116.64
c) 98.76
d) 156.54
2
MACHINE DESIGN/SHOP PRACTICE
Solution: Sy K t F
4K t F
N
=
A
=
(
π D O 2 − Di 2
) = πD
4K t F
⎛
Di 2 ⎞⎟
2⎜
O ⎜1 −
D o 2 ⎟⎠
⎝
thus : D o = 116.64 mm
15. A car is moving at 96.6kph when the brakes are suddenly locked and the car begins to skid. If it takes 2 seconds to slow down the car to 4.83kph, how
far in meters will it have traveled before it car comes to a halt?
a) 53.64
b) 276
c) 137
d) 876
Solution: Velocities, in m/s, Vi = 96.6 kph = 26.83 m / s
Vf = 48.3 kph = 13.42 m / s
2
Distance, s = Vf − Vi = 0 − (26.83) = 53.64m
2a
2(− 6.7 )
Acceleration, a = Vf − Vi = 13.42 − 26.83 = −6.71 m / s 2
t
2
2
16. What is the weight of a 2 steel plates sized ¾” x 3” x 20 ft?
a) 1836 lb
b) 3667 lb
c) 1698 lb
Solution: Density or specific weight of a steel plate = 0.283 lb/ft
(
2
d) 1848 lb
3
)
W = γ V = 0.283 lb / in 3 (0.75 in.)(3)(12 in )(20 )(12 in )(2 ) = 3667.68 lb
17. What load, in kN, must be applied to a 25 mm round steel bar 2.5 m long (E = 207 GPa) to stretch the bar 1.3 mm?
a) 52.84
b) 60
c) 53.048
d) 42.562
⎛π 2⎞
⎛π⎞
2
⎜ D ⎟E
⎜ ⎟ (25) (207 000 )(1.3)
AE
⎝4
⎠
⎝4⎠
δ=
δ=
= 52 837.66 N = 52.84 kN
Solution: F =
L
L
2 500
2
18. A car is travelling at 90 kph when the brakes are applied. If it travels a distance of 60 meters before coming to a stop, what is its acceleration m/s ?
a) – 7.08
b) 6.36
c) – 5.21
d) 5.76
Solution:
⎛ 1 hr ⎞
V 2 − V12 0 − (25)2
⎟⎟ = 25 m / s a = 2
V1 = (90 kph )(1000 m / km )⎜⎜
=
= − 5.20 m / s 2
3600
s
(
)
2
S
2
60
⎝
⎠
19. What is the nominal shear stress at the surface of a 50 mm diameter shaft that is subjected to a torque of 0.48 kN-m?
a) 16.95 MPa
b) 21.65 MPa
c) 19.56 MPa
d) 25.12 MPa
Solution:
ss =
16T
πD
3
=
16 (480 000)
π (50 )
3
= 19.557 N / mm 3 = 19.56 MPa
20. An idler gear of 24 teeth is installed between the 12-tooth pinion with a turning speed of 1800 rpm and a driven 60-tooth gear. Determine the speed of
the driven gear and its direction relative to the driving gear rotation.
a) 630 rpm and opposite direction b) 360 rpm and opposite direction c) 630 rpm and the same direction d) 360 rpm and the same direction
Solution:
⎛ Tp
Ng = Np ⎜
⎜ Tg
⎝
⎞
⎟ = (1800 ) ⎛⎜ 12 ⎞⎟ = 360 rpm and rotates with the same direction of rotation
⎟
⎝ 60 ⎠
⎠
21. What Hp can a 1.5-inch diameter short shaft transmit at 450 rpm?
a) 35 Hp
b) 38 Hp
c) 40 Hp
Solution: For short shaft, P =
d) 42 Hp
D 3 N (1.5)3 (450)
=
= 39.97 Hp
38
38
6
22. A steel shaft 1.75 inches in diameter transmits 40 Hp at 1800 rpm. Assuming a modulus of rigidity of 12 x 10 psi, find the torsional deflection of the
shaft in degrees per foot length.
a) 0.0073
b) 0.0037
c) 0.0063
d) 0.00013
Solution:
θ
T
32T
=
=
=
L JG πD 4 G
⎛ 63 000 Hp ⎞
32⎜⎜
⎟⎟
n
⎝
⎠
π D4 G
=
⎡ 63000(40) ⎤
32 ⎢
⎥
⎣ 1800 ⎦
(
π (1.75)4 12 x 10 6
) = 0.00013 radian = 0.0073
o
23. A spur pinion rotates at 1600 rpm and transmits 50 kW to a mating gear. The pitch diameter of the pinion is 100 mm, and the pressure angle is 20 .
Determine the tangential load, in N.
a) 5 968
b) 5790
c) 5900
d) 5098
3
MACHINE DESIGN/SHOP PRACTICE
⎛ 30P ⎞ 2 ⎡ 30(50 ) ⎤
2⎜
⎟
⎢
⎥
2T
⎣ π (1600) ⎦
⎝ πn ⎠
=
Solution: Ft =
= 5.968 kN = 5 968 N
=
(0.10)
D
D
24. A flywheel weighing 450 kg has a radius of 375 mm. How much energy, in N-m, does the flywheel loss from 180 rpm to 168 rpm?
a) 1472.33
b) 1541.33
c) 1451.33
d) 1433.51
⎛ 180 ⎞
⎟ = 7.069 m / s
⎝ 60 ⎠
Solution: V1 = 2πRN 1 / 60 = 2π (0.375) ⎜
∆KE =
(
)
[
]
⎛ 168 ⎞
V2 = 2πRN 2 / 60 = 2π (0.375)⎜
⎟ = 6.597 m / s
⎝ 60 ⎠
m V12 − V22
450 (7.069 )2 − (6.597 )2
=
= 1451.33 N ⋅ m
2
2
25. A punch punches 1-in diameter hole in a steel plate ¾ inch thick every 10 sec. The actual punching takes 1 sec. The ultimate shear strength of the
2
plate is 60,000 psi. The flywheel of the punch press has a mass moment of inertia of 500 in-lb-sec and rotates at a mean speed of 150 rpm. What is
the speed fluctuation, in rpm?
a) 65.4 rpm
b) 64.5 rpm
c) 6.749 rpm
d) 67.49 rpm
(
)
⎛ ω + ω2 ⎞
⎛1⎞
⎛1⎞
∆KE = ⎜ ⎟ I ω12 − ω12 = ⎜ ⎟ I (ω1 − ω2 )(ω1 + ω2 ) = I (ω1 − ω2 ) ⎜ 1
⎟ = I (ω1 − ω2 ) ω
2
2
2 ⎠
⎝
⎝ ⎠
⎝ ⎠
2πN 2π (150)
=
= 15.71 rad / s
Mean angular velocity, ω =
60
60
Solution:
Punching Force, F = s u (πdt ) = (60 000 )(π )(1)(0.75) = 141 371.67 lb
Kinetic Energy, ∆KE = 1
2
(F) t = (1 2 )(141 371.67 ) ⎛⎜ 0.75 ⎞⎟ = 4417.86 ft ⋅ lb
⎝ 12 ⎠
(
4417.86 ft ⋅ lb)(12 )
∆KE
=
= 6.749 rad / s = 64.5 rpm
Speed Fluctuation, (ω1 − ω 2 ) =
Iω
500 in ⋅ lb ⋅ s 2 (15.71)
(
)
26. With the present water interruptions prevailing in Metro Manila, you have been asked to design an upright cylindrical water tank 6 meters in diameter
and 6 meters high, vented, and to be filled completely with water. Determine the minimum thick ness of the tank plate if the stress is limited to 40 Mpa.
a) 3.3 mm
b) 4.4 mm
c) 5.5 mm
d) 8.8 mm
Solution: p = ρgh = (1000 )(9.8066 )(6 ) = 58 839.6 Pa = 58.8396 kPa
t=
pD (58.8396)(6 )
=
= 0.00441 m = 4.41 mm
2s t
2 (40 000 )
27. A V-belt is to transmit 50 HP to a NH3 compressor. The sheave is 203.2 mm in diameter and turns at 1150 rpm, while the larger sheave turns at 400
rpm. The service factor may be taken as 1.5 and the center distance is equal to the diameter of the sheave. Determine the length of belt.
a) 67 in
b) 77 in
c) 87 in
d) 97 in
⎛ N1
⎝ N2
Solution: D 2 = D1 ⎜⎜
⎞
1150 ⎞
⎟ = (203.2) ⎛⎜
⎟ = 584.2 mm
⎟
⎝ 400 ⎠
⎠
(D − D1 )2 = ⎛ π ⎞(203.2 + 584.2) + 2(584.2) + (584.2 − 203.2)2 = 2467.4 mm
⎛π⎞
L = ⎜ ⎟(D1 + D 2 ) + 2C + 2
⎜ ⎟
4C
4(584.2 )
⎝2⎠
⎝2⎠
L = 97.1 inches
28. In a high-rise building, the elevator rises 366 meters with an operating speed of 5 meters per second and reaches full speed in 10.68 meters. The
2
loaded elevator weighs 2000 kg. Determine the acceleration of the elevator in m/sec .
a) 1.17
b) 2.17
c) 3.17
d) 4.17
Solution: a =
V22 − V12 (5)2 − (0 )2
=
= 1.17 m / s 2
2S
2 (10.68)
29. How do you call the process of producing the residual compressive stress of machine parts, which is performed by directing the a high velocity stream
of hardened balls or pellets at the surface to be treated.
a) Nitriding
b) Shot blasting
c) Peening
d) Tempering
30. It is a process that produces residual compressive stress on the machine part, which uses a series of hammer blows on the surface.
a) Nitriding
b) Shot blasting
c) Peening
d) Tempering
31. What process is used to produce residual compressive stress on the crankshaft?
a) Hardening
b) Shot blasting
c) Peening
d) Nitriding
o
32. It is a surface-hardening process for alloy steels in which the material is heated to 950 F in a nitrogen atmosphere, typically ammonia gas, followed by
slow cooling.
a) Quenching
b) Nitriding
c) Shot blasting
d) Peening
4
MACHINE DESIGN/SHOP PRACTICE
33. Which of the following gases is typically used in nitriding process of surface hardening?
a) Nitrogen gas
b) Carbon dioxide
c) Ammonia gas
d) Hydrogen gas
34. Which of the following is the benefit in using nitriding as a surface-hardening process for alloy steels?
a) Improvement of endurance strength, 50 % or more
b) Improvement of endurance strength, less than 50 %
c) Improvement of endurance strength, more than 50 %
d) 80 % improvement on the endurance strength
35. In estimating the actual endurance strength of steel parts, one of the factors to be considered is the material factor, which of the following is the
recommended material factor for cast steel?
a) 0.70
b) 0.80
c) 0.75
d) 1.0
36. How do you call the level of stress that the part will be permitted to see under operating conditions?
a) Yield stress
b) Endurance stress
c) Design stress
d) Ultimate stress
37. Which of the following column formulas is applicable to cast iron columns?
a) Euler’s formula
b) J.B.Johnson’s formula
d) Secant formula
o
Ans. D. Straight line formula. Cast iron columns are usually designed on the basis of
P
⎡L ⎤
= 9000 − 40 ⎢ e ⎥
A
⎣k ⎦
d) Straight line formula
→ a Straight line formula
o
Where the slenderness ratio Le/k should not exceed 70.
38. Which of the following ferrous metals has the lowest carbon content?
a) Carbon steel
b) Wrought iron
c) Cast iron
d) SAE 4140
o
Wrought iron usually contains less than 0.04% C; steel usually has less than 2.5% C; cast iron has more than 1.7% C; SAE 4140 has
approximately 0.4% C.
39. If stiffness is the main criterion in selecting a material, which of the following is the most economical choice?
a) SAE 3130
b) SAE 1020
c) SAE 6150
d) AISI 301, ¼ hard stainless steel
o
Ans. B. SAE 1020- plain carbon steel. All of the above materials are steel with practically equal modulus of elasticity. The three other materials are
alloy steels that are relatively more expensive.
40. Which of the following materials can easily be machined?
a) AISI C1020
b) AISI C1112
c) AISI C1030
d) AISI C1010
o
Ans. B. C1112. This is a free-cutting steel with a higher sulfur content for ease in machining
41. Wood is an ______ material; that is, its mechanical properties are unique and independent in three mutually perpendicular directions—longitudinal,
radial, and tangential.
a) Isotopic
b) Anisotropic
c) Orthotropic
d) Any of these
42. The principal raw materials used in steelmaking are iron ore, coal, and __________.
a) Coke
b) Limestone
c) Slag
d) Flux
43. The steel part is heated to a temperature of 900–1150 degrees F in an atmosphere of ammonia gas and dissociated ammonia for an extended period
of time that depends on the case depth desired.
a) Nitriding
b) Carburizing
c) Case hardening
d) Cyaniding
44. The primary application of high-speed steels is to tools used for the working of metals __________.
a) that are too hard
b) at high cutting speeds
c) that are too soft
d) at slow cutting speeds
45. In gearing, this is the ratio of the arc of action to the circular pitch.
a) Speed ratio
b) Arc ratio
c) Contact ratio
d) Gear ratio
46. Flywheel arms are usually of elliptical cross-section, the strength of the arms should equal _________the strength of the shaft in torsion.
a) Three-fourths
b) One-half
c) Two-thirds
d) One-fourth
47. This alloy (nickel, iron, chromium, cobalt is a non-magnetic, corrosion resistant material suitable for sub-zero temperatures and temperatures up to
about 750 degrees F., provided that torsional stresses are kept below 75,000 pounds per square inch. It is precipitation-hardened to produce
hardnesses of 48 to 50 Rockwell C and is used in watch and instrument springs.
a) Elinvar
b) Monel
c) Inconel
d) Dynavar
Ans. Dynavar; source: Machinery’s handbook
48. To ensure an adequate factor of safety in the design of a shaft with standard keyway, the key width should be about:
a) One half of the shaft diameter b) One fourth of the shaft diameter c) One eighth of the shaft diameter
d) One third of the shaft diameter
Note: One-fourth of shaft diameter, as a guide in key selection for both square and flat rectangular keys.
49. What is the property of matter that causes it to resist any change in its motion or state of rest?
a) Momentum
b) Kinetic Energy
c) Inertia
d) Section modulus
50. This is defined as the cutting time to reach a predetermined wear, called the tool wear criterion.
a) Wear duration
b) Cycle time
c) Tool life
d) Life cycle
51. Which of the following G-codes refers to rapid traverse in CNC machining?
a) G00
b) G01
c) G02
d) G03
52. An acronym in CNC machining which means access of the machine operator to insert machining instructions directly into the NC machine control
system via push buttons, pressure pads, knobs, or other arrangements.
a) FMS
b) FMC
c) CIM
d) MDI
Note: MDI = manual data input
53. The variable polarity plasma arc (VPPA) process was developed for welding metals that form an oxide skin, such as ___________.
a) Steel
b) Copper
c) Cast iron
d) Aluminum
54. Which of the following statements is NOT true?
a) The terms “polishing” and “buffing” are sometimes applied to similar classes of work in different plants.
b) Polishing is any operation performed with wheels having abrasive glued to the working surfaces
c) Buffing is done with wheels having the abrasive applied loosely
d) Polishing is not so harsh an operation as buffing, and it is commonly utilized to obtain very fine surfaces having a “grainless finish.”
5
MACHINE DESIGN/SHOP PRACTICE
Note: Polishing is harsher than buffing.
55. If the steel is strongly deoxidized by the addition of deoxidizing elements, no gas is evolved, and the steel is technically called _______because it lies
quietly in the molds.
a) Quenched
b) Annealed
c) Killed
d) Tempered
56. Stainless steels generally contain at least __ per cent chromium, with or without other elements.
a) 18
b) 16
c) 12
d) 10
57. What grades of stainless steels are nonmagnetic in the annealed condition, although some may become slightly magnetic after cold working?
a) Ferritic grades
b) Austenitic grades
c) Martensitic grades
d) Any of these
58. These steels (SAE Steels 1006, 1008, 1010, 1015) are the lowest carbon steels of the plain carbon type, and are selected where ________ is the
primary requisite of the user.
a) Strength
b) Cold formability
c) Ductility
d) Durability
59. Steel is heated to a temperature above the critical range, after which it is cooled in still air to produce a generally fine pearlite structure. The purpose is
to promote uniformity of structure and properties after a hot-working operation such as forging or extrusion. What was the heat treatment involved?
a) Annealing
b) Normalizing
c) Tempering
d) Stress relieving
60. At certain speeds called the critical speeds, a rotating shaft will become dynamically unstable and the resulting vibrations and deflections can result in
damage not only to the shaft but to the machine of which it is a part. At what percentage of the critical speed should a shaft be safely operated?
a) Plus or minus 20%
b) Plus or minus 5 %
c) Plus or minus 10 %
d) Any of these
61. This is the most widely used of all spring materials for small springs operating at temperatures up to about 250 degrees F. It is tough, has a high tensile
strength, and can withstand high stresses under repeated loading.
a) Music wire
b) Hard drawn spring wire
c) Oil tempered spring wire
d) Stainless steel spring wire
62. It is an acronym in machining. This process uses an electrode to remove metal from a workpiece by generating electric sparks between conducting
surfaces.
a) MIG
b) GMAW
c) EDM
d) CNC
Ans. Electro-Discharge Machining (Source: Machinery’s Handbook)
63. In die casting accurate parts made of steel, what shrinkage allowance in inches per inch is recommended?
a) 0.011
b) 0.022
c) 0.033
d) 0.044
Ans. 0.022. (Source: Machinery’s Handbook)
64. This are gears used to connect shafts that are non-intersecting and non-parallel. They are a cross between spriral bevel gears and worm gears.
a) Helical gears
b) Hypoid gears
c) Planetary gears
d) Bevel gears
65. This is a type of seal used where some form of relative motion occurs between rigid parts of an assembly.
a) Gasket
b) Distorted seal
c) Vibratory seal
d) Dynamic seal
66. It is a lubrication for roller chains wherein the lubricant is supplied by a circulating pump capable of supplying the chain drive with a continuous flow of
oil inside the chain loop evenly across the chain width and directly at the slack strand.
a) Oil stream lubrication
b) Bath lubrication
c) Drip lubrication
d) Recirculated lubrication
67. In manufacturing, this is the operation of cutting out flat area to some desired shape and is usually the first step in a series of operation.
a) Turning
b) Facing
c) Blanking
d) Finishing
68. An M-code which generally refers to start spindle rotation in a clockwise direction.
a) M03
b) M04
c) M05
Ans. M03-spindle start in a clockwise rotation
69. A final operation to improve the polish of a metal and to bring out the maximum luster
a) Finishing
b) Surface grinding
c) Broaching
d) M06
d) Buffing
70. Machining operations with the proper application of a cutting fluid generally has the following attributes except:
a) Higher cutting speeds
b) Higher feed rates
c) Lengthened tool life
d) Higher cutting accuracy
Ans. D. The use of cutting fluids does not increase cutting accuracy.
71. A material of construction (only developed commercially in the late 1940’s concurrently with zirconium) offers the unique combination of wide ranging
corrosion resistance, low density, and high strength.
a) Tungsten
b) Titanium
c) Vanadium
d) Molybdenum
72. Which of the following is the lightest of all structural metals?
a) Aluminum
b) Copper
c) Magnesium
d) Manganese
73. This process reduces internal stresses, caused by machining, cold working, or welding, by heating the steel to a temperature below the critical range
and holding it there long enough to equalize the temperature throughout the piece.
a) Annealing
b) Normalizing
c) Tempering
d) Stress Relieving
74. A free-cutting steel has a higher ______ content than comparable carbon steels.
a) Sulfur
b) Cobalt
c) Nickel
75. This property designates the steels resistance to the softening effect of elevated temperature.
a) Hot hardness
b) Machinability
c) Toughness
d) Chromium
d) Elasticity
76. Use of hard solders, silver solders and smelter solders which have silver, copper, or nickel bases and have melting points above 800 degrees F is
known as_______
a) Soldering
b) Welding
c) Brazing
d) Any of these
77. In braking, the term backstop refers to a brake that is:
a) Self locking in one direction b) Self enegizing
c) Self locking in both directions
d) Any of these
78. How do you call a fixed crane consisting of a supported vertical member from which extends a horizontal swinging arm carrying a trolley hoist or other
hoisting mechanism?
a) Jib crane
b) Gantry crane
c) Overhead crane d) Tower crane
Ans. a) Jib crane (source: PME Code)
6
MACHINE DESIGN/SHOP PRACTICE
79. This iron is also known as a ductile cast iron. How do you call this iron?
a) Malleable iron
b) Nodular cast iron
c) White cast iron
d) Gray cast iron
Ans. b) Nodular cast iron is a ductile cast iron.
80. It is the ability to deform plastically to compensate for irregularities in bearing assembly. How do you call this?
a) Plasticity
b) Conformability
c) Embeddability
d) Elasticity
81. A material of construction (only developed commercially in the late 1940’s concurrently with zirconium) offers the unique combination of wide ranging
corrosion resistance, low density, and high strength.
a) Titanium
b) Tungsten
c) Vanadium
d) Molybdenum
82. Newton’s law of motion that describes that if a force acts to change the state of motion of the body, the body offers a resistance equal and directly
opposite to the force.
a) Second law
b) Third law
c) First law
d) Universal gravitation
Ans. b) Newton’s third law of motion: Action = Reaction
83. These are steels most widely used of engineering materials. No other material offers comparable versatility for product design.
a) Wrought steels
b) Low carbon steels
c) Medium carbon steels
d) Tool steels
84. Which of the following steels does not readily respond to heat treatment?
a) SAE 1045
b) AISI 6150
c) SAE 1020
d) SAE 1095
o
Low carbon steels (0.3% C and lower) do not readily respond to heat treatment.
85. What is an element added to steel to improve its machinability?
a) Carbon
b) Sulfur
c) Cobalt
d) Chromium
o
Free machining or free cutting carbon contains more sulfur than other steels.
86. Which of the following information is FALSE regarding steel that has increased carbon content?
a) Its strength is increased
b) Its BHN becomes greater c) Its ductility is improved d) Its % reduction or elongation is reduced
o
The ductility of steel is reduced if its carbon content is increased.
87. In manufacturing, what is the operation of cutting out flat area to some desired shape and is usually the first step in a series of operation?
a) Turning
b) Blanking
c) Facing
d) Finishing
Ans. b) Blanking (Source: PME Code)
88. This is a metal joining process which uses a non-ferrous filler metal with a melting point below that of the base metals but above 800°F. How do you call
this process?
a) Brazing
b) Arc welding
c) Soldering
d) Riveting
89. Rivet holes are made usually ____ inch larger in diameter than the nominal diameter of the rivet.
a) 1/8
b) 1/16
c) ¼
d) 1/32
o
Generally 1/16” from MD books (e.g. Black) and from the Machinery’s Handbook.
90. Which of the following equations/formulas does not belong to the group?
a) Lame’s equation
b) Euler’s formula c) J. B. Johnson’s equation
d) Secant formula
o
Lame’s equation is an equation for a thick-walled pressure cylinder. The other 3 are for columns.
91. In CNC programming, which of the following G code commands is for dwell or rest?
a) G01
b) G04
c) G03
d) G02
o
G04 is for dwell or rest; G01 is for linear interpolation; G02 is for circular interpolation CW; G03 is for circular interpolation CCW.
92. In CNC programming, which of the following M code commands is for a tool change?
b) M04
c) M03
d) M10
a) M06
o
M06 is for a tool change; M03 is for spindle start CW; M04 is for spindle start CCW; M10 is for chuck open.
93. Which of the following is a material description referring to unique properties in three mutually perpendicular planes?
a) Isotropy
b) Anisotropy
c) Orthotropy
d) Isometry
Ans. Orthotropy. Example is wood which shows unique properties in the three mutually perpendicular planes.
94. The true stress-strain curve in a stress-stress diagram appears to be:
a) Lower than the engineering stress-strain curve
b) Higher than the engineering stress-strain curve
c) The same as the engineering stress strain curve
d) Symmetrical with the engineering stress-strain curve
o
The true stress-strain curve uses the actual area of the specimen and is therefore higher than the engineering curve which is based on a constant
(original) area of the specimen.
95. This is a hardening treatment for steels having a low carbon content.
a) Tempering
b) Case hardening
c) Normalizing
d) Anodizing
96. What is a manufacturing process used for the production of aluminum?
a) Forging
b) Extrusion
c) Blow molding
d) Injection molding
97. This refers to a loss of material from the interface of two metal surfaces that are in intimate contact. How do you call this?
a) Interfacing
b) Interference
c) Wear
d) Fretting corrosion
98. This is a type of fit that requires heating the hub to expand its inside diameter. What do you call this type of fit?
a) Expansion fit
b) Force fit
c) Shrink fit
d) Any of these
99. AFBMA is an acronym for an association involved in what machine elements?
a) Ball and roller bearings
b) Journal bearings c) Flat belts and other belt types
d) Any type of gears
o
AFBMA means Anti-Friction Bearing Manufacturers’ Association and is concerned with rolling element bearings such as ball, roller, and needle
bearings.
100. What is the general description for mild steel?
a) Medium carbon steel
b) Low carbon steel
c) High carbon steel d) Cold rolled steel
Ans. Mild carbon steels are low carbon steels.
7
MACHINE DESIGN/SHOP PRACTICE
Note: The following questions are for your reading and Familiarization
101. Von Mises theory is the other term used for
a) Maximum principal stress theory
b) Octahedral shear-stress theory
c) Maximum shear-stress theory
d) Energy distortion theory
102. A type of key in which width and thickness are equal is called as:
a) Flat key
b) Square key
c) Pin key
d) Barth key
103. In the design of key, the typical hub lengths are in accordance with the following relation where D is shaft diameter.
a) 1.25D to 2.4D
b) 0.5D to 1.25D
c) 2.4D to 3.5D
d) Depends on shaft diameter
104. A coupling that allows axial flexibility/movement in the operation. Made of alternate bolting of steel, leather, fabric and/or plastic material into two
flanges.
a) Flexible disk coupling
b) Flexible toroidal spring coupling
c) Flexible Oldham coupling
d) Elastic material bonded coupling
105. It is a machine member that supports another part that rotates, slides, or oscillates in or on it.
a) Pulley
b) Key
c) Bearing
d) Shaft
106. It is a bearing that permits constrained relative motion of rigid parts; lubricant is generally inserted or supplied between the mating surfaces to reduce
friction and wear, and to carry away the heat generated.
a) Sliding Contact Bearing
b) Rolling Contact Bearing
c) Thrust Bearing
d) Journal Bearing
107. These are surfaces that do not conform to each other very well as in the rolling-element bearings.
a) Conformal surfaces
b) Non-conformal surfaces
c) Sliding surfaces
d) Rolling surfaces
108. The study of lubrication, friction, and wear of moving or stationary parts is known as:
a) Lubrication
b) Tribology
c) Hydrodynamics
d) Hydrostatics
109. A bearing where surfaces are non-conformed and motion is primarily rolling; it composed of rolling elements interposed between an outer ring and inner
ring.
a) Sliding-element bearing b) Rolling-element bearing c) Conformal surfaces bearing
d) Non-conformal surfaces bearing
110. The ratio of material elongation to temperature rise is called as:
a) Specific heat ratio
b) Thermal expansion coefficient
c) Poisson’s ratio
d) Thermal conductivity ratio
111. The polymers without cross-link is said to be:
a) Thermoplastics
b) Ceramics
b) Glasses
d) Thermosets
112. The polymers with highly cross-linked structure is said to be:
a) Thermoplastics
b) Ceramics
b) Glasses
d) Thermosets
113. Which of the following does not pertain to joining of metals?
a) Welding
b) Soldering
c) Casting
d) Brazing
114. Killed steel is always associated with:
a) Silicon
b) Manganese
c) Phosphoros
d) Sulfur
115. The usual ratio of water to soluble oil used as cutting fluid:
a) 50 % water to 50 % oil b) 2 water to 1 oil
c) 3 water to 1 oil
d) 4 to 80 water to 1 oil
116. Which of the following is the good deoxidiser in steel making?
a) Manganese
b) Silicon
c) Aluminum
d) Any of these
117. Which of the following is a good stabilizer in stainless steel?
a) Columbium
b) Titanium
c) Tantalum
d) All of these
118. What is the common cutting fluid used for cutting metals?
a) Water with soda or borax
b) Light mineral oil
c) Soluble oil
d) All of these
119. It is considered as a semi-solid lubricant. How do you call this/
c) Grease
d) 2T oil
a) Lube oil
b) Graphite
120. Metals are conductive because:
a) The electrons are loosely bound to the nuclei and therefore mobile
b) Having a characteristics metallic luster
c) They are on the left side of the periodic table
d) They have extra electrons as exhibited by normally possible balance state
121. The purpose of these parts in application is to have better bearings to guard against marring, etc.
a) Bearing journal
b) Metallic seal
c) Washer
d) Heat treatment
122. The yield strength of a regular yellow brass (6.5 to 7 % Cu, 30 to 35 % Zn) can be increased/improved by which of the following processes?
a) Cold working
b) Tempering
c) Chill casting
d) Heat treatment
123. Liners are normally made of:
a) Cast iron
b) Alloyed bronze
c) Alloyed steel
d) Alloyed aluminium
124. Endurance strength is nearly proportional to the ultimate strength but not with which of the following?
a) Yield strength
b) Design stress
c) Shear stress
d) All of these
125. Which of the following is a furnace used in melting non-ferrous metals?
a) Cupola furnace
b) Crucible furnace
c) Induction furnace d) Tempering furnace
126. Which of the following is a furnace used in melting ferrous metals?
a) Annealing furnace
b) Tempering furnace
c) Induction furnace
d) Normalizing furnace
127. How do you call the tooth width measured along the chord at the pitch circle?
a) Flank
b) Face width
c) Width of space
d) Chordal thickness
128. Which of the following is the best instrument for measuring a thousandth of an inch?
a) Micrometer
b) Tachometer
c) Caliper
d) Pyrometer
129. All are associated with standard material specification except:
a) American Iron and Steel Institute (AISA)
b) Society of Automotive Engineers (SAE)
c) Southeast Asia iron and Steel Institute (SASI)
d) American Society for Testing Materials (ASTM)
130. How do you call a machine tools used for laying straight lines on metal surfaces made of sharp tool steel?
a) Plain scriber
b) A trammel
c) Hermaphrodite calliper
d) Divider
131. What is the difference of addendum and dedendum which is equivalent to the whole depth less working depth?
a) Fillet space
b) Fillet radius
c) Clearance
d) Backlash
132. How do you call a lathe machine threading mechanism?
a) Reverse gear and lever
b) Spindle gear
c) Change stud gear
d) Feed mechanism
133. How do you call the separate forces that can be so combined?
a) Non-concurrent forces b) Couple
c) Combined forces
d) Concurrent forces
134. What do you call the property of matter that causes it to resist any change in its motion or state of rest?
a) Brake
b) Center cut
c) Inertia
d) Impulse
8
MACHINE DESIGN/SHOP PRACTICE
135. Negative allowance is also called as:
a) Interference of metal b) ACME thread
c) Buttress threads
d) Whitworth thread
136. Which of the following is not used to resemble the shape of tool bit?
a) Round nose
b) Center cut
c) Square nose
d) Thread cutting
137. It is a kind of thread in which the width of the thread is approximately equal to the depth of the thread and the shape between threads are approximately
equal.
a) Square thread
b) ACME thread
c) Buttress thread
d) Whitworth thread
138. A shaft is to be checked for concentricity. Which of the following is a suitable method of performing the check?
a) Bench centers and dial indicator
b) Bench side and calliper
c) Bench top and tachometer
d) Bench target and scriber
139. For moderate speed of mating gears, which of the following is the ideal ratio of contact?
a) 1.25 to 4
b) 1.2 to 1.45
c) 1.0 to 1.3
d) 1.35 to 1.45
140. What is the ratio of unit lateral deformation to unit longitudinal deformation?
a) Poisson’s ratio
b) Strain
c) Elongation
d) Modulus of elasticity
141. What is a lathe with multiple cutting stations?
a) Turret lathe
b) Lathe
c) Shaper
d) Engine lathe
142. What do you call the nominal diameter of bolts?
a) Major diameter
b) Minor diameter
c) Pitch diameter
d) Base diameter
143. Major and minor diameters are commonly used in which of the following machine elements?
a) Screw thread
b) Bolts
c) Gear
d) Annulus
144. The distance of helical gear or worm would thread along its axis in one revolution if it were free to move axially is called as:
a) Length of action
b) Line of action
c) Land
d) Lead
145. The length of contact between two mating parts in a screw and nut threads measured axially is called as:
a) Arc of contact
b) Depth of engagement
c) Length of engagement
d) Axis of contact
146. If the velocity of a mass is the same all the time during which motion takes place is called as:
a) Deceleration
b) Uniform motion
c) Acceleration
d) Variable motion
147. In involute teeth, the pressure angle is often defined as the angle between the line of action and the line of tangent to the pitch circle. It is termed as:
a) Helix angle
b) Angle of recess
c) Angle of obliquity
d) Arc of action
148. Which of the following pressure angles is most commonly used for involute gears?
o
o
o
o
b) 14.5
c) 25
d) 18
a) 20
149. What is the form of pitch surface in bevels gears?
a) Cylindrical
b) Tubeaxial
c) Conical
d) Involute
150. Which of the following is made of a line of action of the tooth with a line tangent to both the pitch circles where these come together?
a) Line of action
b) Pressure angle
c) Pressure line
d) Angle of action
151. Which of the following should be properly related in a pair of spur gears in order to prevent interference?
a) Addendum
b) Dedendum
d) Pressure angle
d) Both a, b, & c
152. Which of the following steels contains nickel?
a) SAE 1056
b) SAE 2040
c) SAE 3140
d) SAE 4140
153. Which of the following is not a classification of iron ore?
a) Hermatite
b) Magnetite
c) Sulfurite
d) Siderite
154. Of the following metals, which will respond to heat treatment?
a) Cast iron
b) Wrought iron
c) Medium carbon steel
d) Low carbon steel
155. What is the ability of metal to withstand loads without breaking down?
a) Stress
b) Strength
c) Strain
d) Elasticity
156. Which of the following metals is non-magnetic?
a) Cast iron
b) Alloy steel
c) Cast steel
d) Manganese steel
157. A machine operation whereby the tool reciprocates and the feed is stationary, is called:
a) shaping
b) reaming
c) planning
d) turning
158. A 48 inches diameter saw blade is mounted on a pulley driven steel shaft, requiring a blade peripheral linear speed of 150 ft/sec. Motor drive is 125 HP
at 1200 rpm, with 6 inches diameter pulley. Determine the shaft pulley diameter.
a) 8 inches
b) 10 inches
c) 12 inches
d) 15 inches
159. The area of a machine shop where metal is being melted to form a new shape is:
a) welding
b) mass production area
c) foundry area
d) tool and die area
160. A machine used in shaping metal by means of abrasive wheel or the removal of metals with an abrasive is called:
a) shaping
b) power saw
c) shaper
d) grinding machine
161. A machining operation whereby the tools rotates while the feed is stationary is called:
a) shaping
b) milling
c) turning
d) reaming
162. Which of the following metals is easy to chisel?
a) alloy steel
b) stainless steel
c) manganese steel
d) cast iron
163. Ferrous metals contain a relatively large amount of:
a) carbon
b) manganese
c) phosphorous
d) sulfur
164. Which of the following is not a strength property of metals?
a) tensile strength
b) rocking strength
c) fatigue strength d) torsional strength
165. Which of the following is not a kind of mandrel?
a) expansion mandrel
b) contraction mandrel
c) taper mandrel
d) gang mandrel
166. A machine which is used to finish internal and external surfaces by the uses of s cutter, which has a series of cutting edges or teeth.
a) broaching machine
b) lathe machine
c) milling machine d) planer
167. Which of the following is not a kind of a cast iron?
a) malleable iron
b) head iron
c) gray iron
d) white iron
168. The kind of center which is being attached and meshed to the tailstock spindle which is also static while the work is rotating is:
a) dead center
b) live center
c) focal center
d) work center
169. Which process does not belong to the group?
a) resistance welding
b) soldering
c) hardening
d) brazing
170. In general, the design stress and factor of safety re related as follows:
a) design stress = ultimate stress times factor of safety
b) design stress = ultimate stress divided by factor of safety
c) factor of safety = design stress divided by ultimate stress
d) Ultimate stress = factor of safety divided by design stress
9
MACHINE DESIGN/SHOP PRACTICE
171. In the usual spur gearing, the:
a) the pitch circle and base circle are the same
b) working depth includes the clearance.
c) tooth outline are usually involute circle.
d) tooth outline are always cycliodal curves.
172. One of the following is not a common term relating to the classification of fits:
a) tunking
b) snug
c) medium force fit
d) bound
173. Galvanized iron is a term referring to iron coated with:
a) tin
b) zinc
c) magnesium
d) aluminum
174. Stainless steel is obtained principally by the use of which alloying elements:
a) chromium
b) nickel
c) carbon
d) tungsten
175. The internal stresses existing in a wield connection are:
a) not relieved by heat treatment
b) not relieved when the welded is peened
c) may be relieved when the weld is peened
d) relieved by x-rays analysis
176. Herringbone gears are gears which:
a) do not operate on parallel shafts
b) have a line contact between teeth
c) consist of two left handed helical gears
d) tend to produce and thrust on the shafts
177. Arc of the pitch circle through which a tooth travels from the point of contact with the mating tooth to the pitch point of a gear.
a) Arc of recess
b) Arc of action
c) Arc of approach d) Arc of relief
178. Molybdenum-chromium-nickel steel designation:
a) SAE 48xx
b) SAE 43xx
c) SAE 56xx
d) SAE46xx
179. The function of the clutch in the machine tools is:
a) Lowering the drive speed
b) To disconnect or connect the shaft at will the drive
c) Alignment of drive shaft
d) To insure that two shafts line up at high speed
180. Should two equal and opposite collinear forces is added to the forces already in equilibrium, which of the following statements is true?
a) Unbalanced moment is maintained
b) Equilibrium is maintained
c) Equilibrium is distributed
c) It creates an unbalanced situation
181. Also called as eccentricity loaded bearing:
a) Full bearing
b) Offset bearing
c) Partial bearing
d) Fitted bearing
182. Which of the following is not a heat treatment process?
a) Sintering
b) Annealing
c) Hardening
d) Tempering
183. An instrument used to analyse the compositions of metals:
a) Spectrometer
b) Radiometer
c) Profilometer
d) Ultimate analyser
184. Creep is the term used in referring to the:
a) Elongation before yield point
b) Maximum stress of brittle materials
c) Fatigue limit of ductile materials
d) Continuous increase in the strain, or deformation, of any material subjected to stress
185. Splines are used when:
a) The power to be transmitted is high b) The torque is high
c) The speed is high
d) Axial relative motion between shaft and hub is necessary
186. Which of the following contains chromium?
a) SAE 2340
b) SAE 4230
c) SAE 5240
d) SAE 1230
187. The lack of backlash in a spur gear design/operation may result to:
a) Overloading
b) Jamming
c) Overheating
d) All of these
188. The strength of non-ferrous alloys is maximum at room temperature while that of ferrous metal has a maximum strength at:
o
o
o
o
b) 450 F
c) 1200 F
d) 350 F
a) 400 F
189. One of the typical types of steel used as spring material.
a) Song wire
b) Guitar wire
c) Piano wire
d) Rope wire
190. A high-quality high-carbon wire that is widely used as spring material in the smaller diameters.
a) Silicon bronze
b) Music wire
c) Beryllium copper d) Stainless Steel 302
191. A hydrostatic bearing is one which:
a) Lube oil is supplied under pressure
c) Lube oil is not pressurized
192. The corrosion of iron-base-alloys:
a) Rusting
b) Crazing
b) There is no lube
d) Bearing is slightly loaded
c) Chalking
d) Fritting
193. The property of a material that measures the degree of plastic deformation sustained at fracture.
a) Toughness
b) Stiffness
c) Ductility
d) Brittleness
194. The combination of applied normal and shear stresses that produces maximum principal normal stress or minimum principal normal stress, with a third
principal stress between or equivalent to the extremes.
a) Principal shear stress
b) Principal normal stress
c) Maximum shear stress
d) Bending and shear stresses
195. In a straight bevel gear the angle between an element on the pitch cone and an element on the face cone is called:
a) Face angle
b) Pitch angle
c) Addendum angle
d) Dedendum angle
196. A Grashof four-bar mechanism in which the shortest link is the frame or fixed link and the other two cranks completely rotate with their axes.
a) Drag-link mechanism
b) Crank-rocker mechanism
c) Double-rocker mechanism
d) Triple-rocker mechanism
10
MACHINE DESIGN/SHOP PRACTICE
JCSF ENGINEERING REVIEW CENTER
2nd Floor Santos‐Causing Building, National Highway
Halang, City of Calamba, Laguna
MACHINE DESIGN AND SHOP PRACTICE (Refreshers Trivia # 4)
Prepared by: Jose R. Francisco, PME
September 2012
MULTIPLE CHOICE QUESTIONS
Select the best answer from each of the following questions. On the answer sheet provided, shade the box that corresponds to your choice. Strictly no
erasures allowed.
1.
A 30-inch-diameter wheel with a frictionless axle is embedded 1 inch deep in the ground. It supports a load of 100 lb. What horizontal force applies at
the axle, in lb, is needed to start the wheel rolling?
a) 38.5 lb
b) 83.5 lb
c) 53.8 lb
d) 35.8 lb
W = 100 lb
Solution:
⎛ 15 − 1 ⎞
a = 14 tan 21.04 = 5.385 inches
θ = arccos ⎜
= 21.04o
⎟
⎝ 15 ⎠
Wa 100 ( 5.385 )
F=
=
= 38.5 lb
14
14
2.
L=
( 4000 N )(1000 )
F
=
= 87.47 mm
pD 1300000 N / m 2 ( 0.036 m )
(
L 85.47
=
= 2.374 ≈ 2.4
D
36
)
(
⎡ π Do4 − Di4
⎛ πD3 ⎞
ss ⎜
⎟ = ss ⎢
⎢⎣ 16Do
⎝ 16 ⎠
) ⎤⎥ →
D3 Do = D o4 − Di4
(
) = [(50)
⎥⎦
D i = D o4 − D 3 D o
1
4
]
1
4
− (25)3 (50 ) 4 = 48.358 mm
A 4 inches shaft using a flat key, whose width is 1 inch, is transmitting a torque of 63000 in-lb. If the design shearing stress is 5000 psi, determine the
safe length of key, in inches.
a) 5.3 inches
b) 4.3 inches
c) 6.3 inches
d) 7.3 inches
Solution:
5.
a
A 25-mm solid shaft is to be replaced with a hollow shaft of equal torsional strength having an outside diameter of 50 mm. Determine the inside
diameter, in mm, of the hollow shaft.
a) 48.358 mm
b) 38.458 mm
c) 58.438 mm
d) 35.483 mm
Solution:
4.
θ
A 36-mm shaft uses a sleeve bearing that sustains a load of 4000 N. If the allowable bearing pressure of 1.3 MPa, find the bearing length to the
diameter ratio.
a) 4.2
b) 2.4
c) 3.2
d) 2.3
Solution:
3.
F
L=
2 ( 63000 )
2T
=
= 6.3 inches
bss D 1( 5000 )( 4 )
Determine the power capacity, in kW, of a cone clutch under uniform pressure and assuming the following conditions: Major diameter = 250 mm; minor
diameter = 200 mm; length of conical elements in contact = 125 mm; rotational speed = 870 rpm; coefficient of friction = 0.30; and allowable pressure =
70 kPa.
a) 19.2 kW
b) 29.1 kW
c) 21.9 kW
d) 12.9 kW
Solution:
3
3
⎞ 2 ⎡ (125 ) − (100 ) ⎤
⎢
⎥ = 112.96 mm ≈ 113 mm
=
⎟
2
2
⎠ 3 ⎢⎣ (125 ) − (100 ) ⎥⎦
Fn = pA f = p ( 2πrf ) b = 70 ( 2π )( 0.113)( 0.125 ) = 6.212 kN
2 ⎛ r3 − r3
rf = ⎜ o2 i2
3 ⎝ ro − ri
θ
Fa
Tf = f Fn rf = 0.30 ( 6.212 )( 0.113) = 0.2106 kN ⋅ m
P=
πnTf π ( 870 )( 0.2106 )
=
= 19.2 kW
30
30
1
p
MACHINE DESIGN/SHOP PRACTICE
6. A cantilever beam of uniform rectangular cross-section carries an electric motor weighing 40 kg at a distance of 30 cm from the fixed end. The
2
allowable design bending stress in the beam is 400 kg/cm . Determine the depth of the beam, in cm, if depth is twice the width.
a) 3.30 cm
b) 3.30 mm
c) 2.20 cm
d) 2.20 mm
40 kg
Solution:
h
30 cm
sf =
Mc
=
I
( 40 kg )( 30 cm ) ⎛⎜
h⎞
⎟
⎝2⎠
3
bh
12
=
12 ( 40 )( 30 )
2bh
2
b
=
6 ( 40 )( 30 )
b ( 2b )
2
=
1800
= 400
b3
1
⎛ 1800 ⎞ 3
b=⎜
⎟ = 1.65 cm
⎝ 400 ⎠
7.
o
A 20 straight-tooth bevel pinion having 14 teeth and a diametral pitch of 6 teeth/inch drives a 32-tooth gear. The two shafts are at right angles and in
the same plane. The pinion is to transmit 1800 rpm and transmitting 50 hp. Determine the pitch diameters of the gears.
a) 5.92 cm and 13.61 cm
b) 2.59 cm and 11.36 cm
c) 9.52 cm and 16.31cm
d) 2.33 cm and 2.33 cm
Solution:
8.
h = 2b = 2(1.65) = 3.30 cm
D1 =
⎛T ⎞
⎛ 32 ⎞
D 2 = D1 ⎜ 2 ⎟ = ( 2.33) ⎜ ⎟ = 5.36 inches
⎝ 14 ⎠
⎝ T1 ⎠
T1 14
=
= 2.33 inches
Pd
6
A single square thread power screw is to raise a load of 70 kN. The screw has a major diameter of 36 mm and a pitch of 6 mm. The coefficient of
thread friction and collar friction are 0.13 and 0.10 respectively. If the collar mean diameter is 90 mm and the screw turns at 60 rpm, find the axial linear
speed of the screw.
a) 0.24 ips
b) 0.14 ips
c) 0.42 ips
d) 0.34 ips
Solution: For the linear speed of the screw, Vn = n (L) = (60 rpm)(6 mm/rev) = 360 mm/min = 6 mm/s = 0.24 ips
9.
With the arc welding rate of 18 inches per minute, how long will it take to weld ½ inch thick plate by 3 ft long seam.
a) 3 minutes
b) 2 minutes
c) 1.5 minutes
d) 4 minutes
Solution:
t=
(3 ft )(12 inches / ft ) = 2 min utes
18 inches / min
10. How long will it take to mill a ¾ inch by 2 inches long keyway in a 3 inches diameter shafting with a 24-tooth cutter turning at 100 rpm and 0.005 inch
feed per tooth?
a) 0.136 min
b) 0.196 min
c) 0.167 min
d) 0.106 min
Solution:
time =
Length of cut
2 inches
=
= 0.167 min
(24 teeth / rev)(100 rev / min )(0.005 inch / tooth )
Cutting rate
11. The tooth thickness of a gear is 0.5 inch and its circular pitch is 1.0 inch. Calculate the dedendum of the gear.
a) 0.3183 inch
b) 1.250 inches
c) 0.3979 inch
d) 0.1114 inch
Solution:
pd =
π
π
= =π
pc 1
Ded =
1.25 1.25
=
= 0.3979 inch
pd
π
12. What is the pitch of an American Standard Screw Threads with designation 12-28 UNF?
a) 0.083 inch
b) 0.0357 inch
c) 0.5 inch
Solution: p =
d) 0.75 inch
1
1
1
=
=
= 0.0357 inch
n No. of threads per inch 28
13. A helical coil spring has mean coil diameter of 24 mm and a wire diameter of 3 mm. If the shearing stress is 413.6 MPa, how much load can it support?
a) 195.33 N
b) 145.33 N
c) 154.33 N
d) 165.33 N
Solution:
C=
D m 24
=
=8
d
3
Kw =
4C − 1 0.615 4(8) − 1 0.615
+
=
+
= 1.184
4C − 4
C
4(8) − 8
8
2
MACHINE DESIGN/SHOP PRACTICE
F=
(
)
πd 3 s s
π(3 mm )3 413.6 N / mm 2
=
= 154.33 N
8K w D m
8(1.184 )(24 mm )
14. What is the number of threads per mm of a standard Metric screw Thread designated by M10 x 1.5?
a) 0.555
b) 0.667
c) 1.5
d) 1.75
Solution:
n=
1
1
=
= 0.667 threads per mm
p 1.5
For Standard Metric Screw Threads,
A t = 0.7854(D − 0.9383p )2 = 0.7854[10 − 0.9383(2.5)]2 = 57.99 mm 2
2
Where At = tensile stress Area, mm ; D = basic major diameter, mm; p = pitch, mm
Note: M stands for standard metric screw threads; 10 stands for the basic major diameter, which is 10 mm;
1.5 stands for pitch that is 1.5 mm.
15. Compute the speed of the gear mounted on a 52.5 mm diameter shaft receiving power from a driving motor with 250 Hp.
a) 2 182 rpm
b) 2 071 rpm
c) 2 265 rpm
d) 2 341 rpm
Solution: From PSME Code:
N=
80 P
D
3
=
80 (250 )
⎛ 52.5 ⎞
⎜
⎟
⎝ 25.4 ⎠
3
= 2 264.92 rpm
16. It is a typical of material used for cylinder block.
a) Forged steel
c) Cast iron and coated with chrome or molybdenum
17. Which of the following is a material used for a piston ring?
a) Forged steel
c) Cast iron and coated with chrome or molybdenum
b) Drop-forged, heat-treated steel\
d) Cast iron
b) Drop-forged, heat-treated steel\
d) Cast iron
18. Which of the following is the typical material used for an engine crank shaft?
a) Forged steel
b) Heat-treated steel
c) Cast iron
19. In flange coupling, which of the following is the weakest element?
a) Flange
b) Shaft
20. What is the function of a governor?
a) Store energy and give up whatever needed
c) Increase variation of speed
21. A cam with a roller follower would constitute which type of pair?
a) Lower pair
b) Open pair
22. Which of the following is not a strength property of metals?
a) Tensile
b) Fatigue
23. Which of the following is not the work of a Machinist?
a) Reboring
b) Overhauling
c) Bolt brush
d) Wrought iron
d) Key
b) Regulate the speed during one cycle of a prime mover
d) Adjust variation of speed by varying the input to the engine
c) Higher pair
d) Closed pair
c) Rocking strength
d) Torsional strenght
c) Grinding
d) Boring
24. What is a machine used in testing steel generally strike the specimen with energy from 220 to 265 ft-lb?
a) Izod test
b) Charpy test
c) Rockwell test
d) Test blockd
25. What is the use of gear tooth vernier?
a) Use for measuring gear tooth profile
b) Use for measuring module
c) Used for measuring pitch line thickness of gear tooth
d) Used for measuring gear tooth thickness
26. What is the use of gagger?
a) A tool used in cleaning welds
b) A tool used in cleaning material before welding
c) A tool used in foundry for cleaning of castings
d) A shaped metal accessory
27. Almost always the soldering materials are a combination of which of the following alloys?
a) Lead and tin
b) Tin and antimony c) Lead and antimony
d) Both a, b & c
28. Concentricity of an outside diameter of the shaft can be checked by using:
a) Bench center and dial test indicator
b) Bench bottom and calliper
c) Bench vise and planar
d) Center post meter
29. Why ball bearings are provided with a cage?
a) To maintain the balls at fixed distance apart
b) To reduce friction
c) To facilitate slipping of balls
d) To prevent the lubricant from flowing out
30. Tin base white metals are used where the bearings are subjected to:
a) Larger surface wear
b) Elevated temperature
c) Light load and pressure
d) High pressure and load
31. One of the following materials is unsuitable as bearing material.
a) Teflon
b) Cast iron
32. What is a Babbitt?
a) A eutectic of iron and iron phosphide
c) Antimony bearing lead or tin alloy
c) Low carbon steel
d) Nylon
b) A gadget for measuring volume
d) A measure of magnetic induction produced in a material
3
MACHINE DESIGN/SHOP PRACTICE
33. The algebraic difference between the maximum limit and the corresponding basic size.
a) Fundamental deviation
b) Upper deviation c) Lower deviation
d) Tolerance
34. In small quantity of this alloy is effective for improving strength at high temperature. How do you call this alloy?
a) Manganese
b) Molybdenum
c) Chromium
d) Selenium
35. Which of the following is not a structural class of steel?
a) Low carbon steel
b) Tool and die steel
c) High chrome alloy steel
36. Ordinary steel begins to loose strength and elasticity significantly at about:
o
o
o
b) 800 to 900 F
c) 750 to 850 F
a) 900 to 1000 F
d) High strength low allow steel
o
d) 600 to 700 F
37. Clearance to a new boiler installation to the existing or old plant building should follow a minimum clearance of ________ between top of the boiler
proper and the ceiling as stated in the PSME Code.
a) 2000 mm (max)
b) 1000 mm (max)
c) 2130 mm (max)
d) 2150 mm (max)
38. For a high corrosion resistant stainless steel, what minimum chromium content is required?
a) 8 %
b) 4.3 %
c) 1.1 %
d) 5.8 %
39. V-belt operate efficiently at speed of about:
a) 4500 fpm
b) 4400 fpm
c) 4200 fpm
40. The usual ratio of water to soluble oil used as cutting fluid.
a) 50 % water to 50 % oil b) 2 water to 1 oil
c) 3 water to 1 oil
d) 3600 fpm
d) 4 to 80 water to 1 oil
th
41. Which of the following is the 4 most commonly used metal in the world?
a) Zinc
b) Steel
c) Aluminum
42. In a pressure vessel, the usual factor of safety may be taken as:
a) 2
b) 4
c) 3
d) Copper
d) 5
43. For thrust bearings, the speed at the moderate operating condition is
b) 50 < Vm < 220 fpm
c) 50 < Vm< 250 fpm
d) 50 < Vm < 290 fpm
a) 50 < Vm < 200 fpm
44. Experience suggests that the most economical designs are obtained for a belt speed of
a) 4000 to 4500 fpm
b) 2000 to 3000 fpm c) 3000 to 4000 fpm d) 4000 to 5000 fpm
45. For leather belts, recommended speed is
a) 6000 to 7500 fpm
b) 2000 to 3000 fpm c) 7000 to 8000 fpm
d) 4000 to 5000 fpm
46. Which of the following is the benefit in using nitriding as a surface-hardening process for alloy steels?
a) Improvement of endurance strength, 50 % or more
b) Improvement of endurance strength, less than 50 %
c) Improvement of endurance strength, more than 50 % d) 80 % improvement on the endurance strenght
47. In estimating the actual endurance strength of steel parts, one of the factors to be considered is the material factor, which of the following is the
recommended material factor for cast steel?
a) 0.70
b) 0.80
c) 0.75
d) 1.0
48. If stiffness is the main criterion in selecting a material, which of the following is the most economical choice?
a) SAE 3130
b) SAE 1020
c) SAE 6150
d) AISI 301, ¼ hard stainless steel
o
Ans. B. SAE 1020- plain carbon steel. All of the above materials are steel with practically equal modulus of elasticity. The three other materials are
alloy steels that are relatively more expensive.
49. Which of the following materials can easily be machined?
a) AISI C1020
b) AISI C1112
o
c) AISI C1030
d) AISI C1010
Ans. B. C1112. This is a free-cutting steel with a higher sulfur content for ease in machining
50. To ensure an adequate factor of safety in the design of a shaft with standard keyway, the key width should be about:
a) One half of the shaft diameter
b) One fourth of the shaft diameter
c) One eighth of the shaft diameter
d) One third of the shaft diameter
51. In die casting accurate parts made of steel, what shrinkage allowance in inches per inch is recommended?
a) 0.011
b) 0.022
c) 0.033
d) 0.044
Ans. 0.022. (Source: Machinery’s Handbook)
52. Which of the following steels does not readily respond to heat treatment?
a) SAE 1045
b) AISI 6150
c) SAE 1020
o
d) SAE 1095
Low carbon steels (0.3% C and lower) do not readily respond to heat treatment.
53. Rivet holes are made usually ____ inch larger in diameter than the nominal diameter of the rivet.
a) 1/8
b) 1/16
c) ¼
d) 1/32
o
Generally 1/16” from MD books (e.g. Black) and from the Machinery’s Handbook.
54. In the design of key, the typical hub lengths are in accordance with the following relation where D is shaft diameter.
a) 1.25D to 2.4D
b) 0.5D to 1.25D
c) 2.4D to 3.5D
d) Depends on shaft diameter
55. As one example, the ASME for riveted joints permits the design surface compressive stress to be about __________ higher than the design stress.
a) 50 %
b) 40 %
c) 60 %
d) 70 %
56. When tested in compression, ductile materials usually exhibit ________ characteristics up to the yield strength as they do when tested in tension.
4
MACHINE DESIGN/SHOP PRACTICE
a) The same
b) Less than
c) More than
d) Approximately the same
57. The hardness of helical and herring bone teeth cut after heat treatment eill generally fall between the limits of
a) 210 and 300 Brinell
b) 147 to 300 Brinell c) 230 and 320 Brinell
d) 220 and 320 Brinell
58. The typical helix angle ranges form ____ to _____.
o
o
o
o
o
o
o
o
b) 10 to 12
c) 14 to 20
d) 15 to 25
a) 12 to 15
59. The hardness of helical and herring bone teeth cut after heat treatment eill generally fall between the limits of
a) 210 and 300 Brinell
b) 147 to 300 Brinell c) 230 and 320 Brinell
d) 220 and 320 Brinell
60. The typical helix angle ranges form ____ to _____.
o
o
o
o
b) 10 to 12
a) 12 to 15
61. Molybdenum-chromium-nickel steel designation:
a) SAE 48xx
b) SAE 43xx
o
o
d) 15 to 25
c) SAE 56xx
d) SAE46xx
c) 14 to 20
o
o
62. One of the causes of spur gear tooth breakage is the unbalanced load on one end of the tooth that results in higher stresses than when the load is
evenly distributed. To minimize this problem, the face width “b” should not be greater than the thickness (or pitch) of the tooth. In the absence of test
values, the following can be a guide:
b) 2pd < b < 4 pd
c) 2.5pd < b < 4pd
d) 2pc < b < 4 pc
a) 2.5pc < b < 4pc
63. It is advised that in rubber belts applications/mountings, it should have an initial tension of:
a) 18 to 24 lb/inch-ply
b) 15 to 20 lb/inch-ply
c) 12 to 15 lb/inch-ply
d) 10 lb/inch-ply
64. Recommended best cutting angle of drill for work on steel or cast iron is:
a) 48 degree
b) 63 degrees
c) 59 degrees
d) 50 degrees
65. The use of hardened steel for the mating metal gear appears to give the best results and longer operational life. The usual hardness is in the range of
which of the following?
a) Below 400 BHN
b) Below 350 BHN
c) 300 to 400 BHN
d) Over 600 BHN
o
66. What do you call a bevel gear having pitch cone angle of 45 ?
a) helical gear
b) Spur gear
c) Crown gear
d) Miter gear
67. Which of the following is an alloy of nickel, iron, chromium and cobalt?
a) Elgiloys
b) Ni-span C
c) Austenite
d) Babbitt
68. Which of the following is the SAE specification number of molybdenum?
a) SAE 2xxx
b) SAE 3xxx
c) SAE 4xxx
69. Which of the following does not belong the group?
a) SAE
b) SEAII
c) AISI
d) SAE 5xxx
d) ASTM
Note: SAE – Society of Automotive Engineers
AISI – American Iron and Steel Institute
ASTM – American Society of Testing and Materials
70. It is the ratio of heat stored per mass to change in temperature of material.
a) Thermal Capacity
b) Specific heat capacity
c) Strain capacity
d) Poisson’s ratio
71. It is the increase in hardness and strength of ductile material as it is plastically performed.
a) Strain hardening
b) Surface hardening
c) Cold hardening d) Hot hardening
72. It is the ability of material to transmit heat.
a) Specific heat capacity
b) Thermal capacity c) Thermal conductivity
73. The ratio of material elongation to temperature rise is called as:
a) Specific heat ratio
b) Thermal expansion coefficient
c) Poisson’s ratio
d) British thermal unit
d) Thermal conductivity ratio
74. The polymers without cross-link is said to be:
a) Thermoplastics
b) Ceramics
b) Glasses
d) Thermosets
75. A process where parts produced quickly from computer geometry description files is known as:
a) Rapid prototyping
b) Machine Synthesis
c) AutoCAD
d) Computer-Aided Design
76. An additional capacity or incorporation of back up systems so that a component failure does not lead to catastrophic loss.
a) Redundancy
b) Expert system
c) Fault free analysis
d) Prototyping
77. The ratio of allowable stress to a design stress.
a) Stress concentration Factor
b) Safety Factor
c) Wahl Factor
d) Failure Factor
78. The measure of angular distortion in which shear stress is applied is said to be:
a) Shear load
b) Shear strain
c) Shear stress
d) Bending load
79. Positive if elongation is in direction of positive axes.
a) Sign convention for normal strain
b) Sign convention for normal stress
c) Sign convention for linear deflection
d) Sign convention for stress
80. Vickers, Knoop and Brinell are all names of which of the following?
a) Hardness tests
b) Thermodynamics constants
c) Magnetic constants
d) Nobel prize in winners in metallurgy
81. What is a killed steel?
a) More oxygen steel
b) Oxidized steel
c) More carbon steel
d) Deoxidized steel
82. In a chain drive design for large speed reduction, it is preferable to use a double reduction of compound type of transmission instead of single two
sprockets transmission. Drives should be so designed that the angle between two tight chain strand does not exceed:
o
o
o
o
b) 55
c) 60
d) 90
a) 45
83. The product of the mass and the linear velocity of a body is called as:
a) Linear impulse
b) Linear momentum
c) Couple
d) Vector
5
MACHINE DESIGN/SHOP PRACTICE
84. How do you call a fixed crane consisting of a supported vertical member from which extends a horizontal swinging arm carrying a trolley hoist or other
hoisting mechanism?
a) Jib crane
b) Gantry crane
c) Overhead crane d) Tower crane
Ans. a) Jib crane (source: PME Code)
85. This iron is also known as a ductile cast iron. How do you call this iron?
a) Malleable iron
b) Nodular cast iron
c) White cast iron
Ans. b) Nodular cast iron is a ductile cast iron.
d) Gray cast iron
86. It is the ability to deform plastically to compensate for irregularities in bearing assembly. How do you call this?
a) Plasticity
b) Conformability
c) Embeddability
d) Elasticity
87. A material of construction (only developed commercially in the late 1940’s concurrently with zirconium) offers the unique combination of wide ranging
corrosion resistance, low density, and high strength.
a) Titanium
b) Tungsten
c) Vanadium
d) Molybdenum
88. Newton’s law of motion that describes that if a force acts to change the state of motion of the body, the body offers a resistance equal and directly
opposite to the force.
a) Second law
b) Third law
c) First law
d) Universal gravitation
89. What is the general description for mild steel?
a) Medium carbon steel
b) Low carbon steel
c) High carbon steel d) Cold rolled steel
90. An old rule of thumb for transmission shafting is that the deflection should not exceed _______ of length between supports.
a) 0.01 inch per foot
b) 0.03 inch per foot
c) 0.02 inch per foot d) 0.04 inch per foot
91. In general, for machinery shafts, the permissible deflection may be closer to:
a) 0.02 inch per foot
b) 0.01 inch per foot
c) 0.002 inch per foot
d) 0.03 inch per foot
92. It is the dominant casting material, primarily because of its low cost, good fluidity, low shrinkage, ease of control, and wide range of properties, including
useful strength and rigidity. What do you call this material?
a) Rubber
b) Cast iron
c) Chromium
d) Carbon
2
93. An air cylinder has a bore of 25 mm and is operated with shop air at a pressure of 6.327 kg/cm . Find the push force exerted by the piston rod, in N.
a) 127.57
b) 70.42
c) 402.75
d) 304.57
Solution:
(
)
⎛π⎞
⎛π⎞
F = pA = p⎜ ⎟ D 2 = 6.327 kg / cm 2 (9.8066 N / kg )⎜ ⎟(2.5 cm )2 = 304.57 N
⎝4⎠
⎝4⎠
94. A double-thread worm has a pitch diameter of 3 inches. The wheel has 20 teeth and a pitch diameter of 5 inches. Find the gear helix angle.
o
o
o
o
b) 9.46
c) 6.49
d) 6.94
a) 4.69
Solution:
⎡⎛ T
λ = tan −1 ⎢⎜⎜ w
⎢⎣⎝ Tg
⎞⎛ D g
⎟⎟⎜
⎜
⎠⎝ D w
⎞⎤
⎡
⎤
⎟⎥ = tan −1 ⎢ 2 ⎛⎜ 5 ⎞⎟⎥ = 9.46 o
⎟⎥
⎣ 20 ⎝ 3 ⎠⎦
⎠⎦
95. If two parallel shafts are connected by cylinders in pure rolling contact and turning in the same direction, and having a speed ratio of 2.75, what is the
Center distance of the two shafts assuming that the diameter of the smaller cylinder is 22 cm?
a) 18.25 cm
b) 19.25 cm
c) 20.25 cm
d) 17.25 cm
Solution:
Diameter of the bigger cylinder, D 2 = SR (D1 ) = 2.75(22 ) = 60.5 cm
Center distance, C =
D 2 − D1 60.5 − 22
=
= 19.25 cm
2
2
96. Three extension springs are hooked in series that support a single weight of 100 kg. The first spring is rated at 4 kN/m and the other two springs are
rated 6 kN/m each. Determine the equivalent stiffness of the three springs.
a) 1.71 kN/m
b) 5 kN/m
c) 2.71 kN/m
d) 3.71 kN/m
Solution:
1
1
1
1
1 1 1 1 1 3+ 4 7
=
+
+
= + + = + =
=
k e k1 k 2 k 3 4 6 6 4 3
12
12
ke =
12
= 1.71 kN / m
7
97. Three extension springs are hooked in parallel that support a single weight of 100 kg. The springs are rated 4 kN/m, 5 kN/m, and 6 kN/m, respectively.
Determine the equivalent spring constant of the three springs.
a) 10 kN/m
b) 15 kN/m
c) 9 kN/m
d) 11 kN/m
Solution: k e = k 1 + k 2 + k 3 = 4 + 5 + 6 = 15 kN / m
98. A single square thread power screw is to raise a load of 70 kN. The screw has a major diameter of 36 mm and a pitch of 6 mm. The coefficient of
thread friction and collar friction are 0.13 and 0.10 respectively. If the collar mean diameter is 90 mm and the screw turns at 60 rpm, find the axial linear
speed of the screw.
a) 5 mm/s
b) 6 mm/s
c) 7 mm/s
d) 5.5 mm/s
Solution: For the linear speed of the screw,
Vn = n (L) = (60 rpm)(6 mm/rev) = 360 mm/min = 6 mm/s
99. Which of the following are the compositions of stainless steel 302?
a) 18 % chromium and 8 % nickel
b) 18 % nickel and 8 % chromium
c) 18 % chromium and 8 % phosphor bronze
d) 18 % bronze and 8 % vanadium
100. These springs are made from one or more flat strips of brass, bronze, steel or other materials loaded as cantilevers or simple beam.
a) Torsion springs
b) Leaf springs
c) Garter springs
d) Drawbar springs
6
MACHINE DESIGN/SHOP PRACTICE
Note: The following questions are for your reading and Familiarization
SET A
101. This refers to the space between adjacent coils when the spring is compressed to its operating length.
a) Coil clearance
b) Pitch
c) Lead
d) Deflection
102. This material is the most popular alloy spring steel for conditions involving higher stresses than can be used with the high-carbon steels and for use
where fatigue resistance and long endurance are needed; this is also good for shock and impact loads.
a) Chrome silicon
b) Chrome vanadium
c) hard-drawn wire
d) Oil-tempered wire
103. For an American Standard Screw Threads, what does 6-32 UNC designate?
a) Size 6, 32 threads per inch, coarse thread
b) 6 inches basic diameter, 32 threads per inch, coarse thread
c) Size 6, 32 threads per inch, fine thread
d) 32 inches basic diameter, 6 threads per inch, coarse thread
Note: 6 stands for the designated size, 32 stands for the number of threads per inch, UNC stands for Coarse threads
104. In a straight bevel gear, how do you call the angle between an element on the pitch cone and an element on the face cone?
a) Face angle
b) Pitch angle
c) Addendum angle
d) Dedendum angle
105. It is a Grashof four-bar mechanism in which the shortest link is the frame or fixed link and the other two cranks completely rotate with their axes.
How do you call this Grashof four-bar mechanism?
a) Drag-link mechanism
b) Crank-rocker mechanism
c) Double-rocker mechanism
d) Triple-rocker mechanism
106. “For a planar four-bar linkage, the sum of the shortest and longest lengths cannot be greater than the sum of the remaining two link lengths if there
is to be a continuous relative rotation between two members.” How do you call the preceding statement?
a) Grubler’s Law
b) Coriolli’s Law
c) Grashof’s Law d) Freudentein’s Law
107. Which of the following is not true for an instant center or centro of planar linkages?
a) Centro is a point common to two bodies having the same velocity in each.
b) Centro is a point in one body about which another body does not rotate.
c) Centro is a point in one body about which another body actually turns.
d) Centro is a point in one body about which another body tends to turn.
108. This is the most common work holding device of a shaper machine with the base graduated in degrees that make it possible to swivel any angle.
What is this working device?
a) Shaper vise
b) Parallel bars and hold down bars
c) Lathe holder
d) Swivel head
109. This is a shaper operation, which is shaping the given stock and having the excess material remain with a tolerable allowance for finishing. How do
you call this operation?
a) Roughing
b) Finishing
c) Angular cutting d) Contouring
110. How do you call a cutting tool that has two or more cutting edges as in drill presses and milling machine cutters?
a) Grinder
b) Single-point cutting tool
c) Multi-point cutting tool
d) Two point cutting tool
111. This is the trade name for a patented alloy made up chiefly of cobalt, chromium, and tungsten in varying proportions. What is this trade name?
a) Stellite
b) Carboloy
c) Stainless steel
d) Copper
112. It is called as the transformation of concepts and ideas into useful machinery. What is this?
a) Design
b) Synthesis
c) Analysis
d) Theorem
113. This is a combination of mechanisms and other components that transforms, transmits, or uses energy, load, or motion for a specific purpose. How
do yopu call this?
a) Mechanism
b) Engine
c) Machine
d) Linkage
114. It is defined as synergistic collection of machine elements; synergistic because as a design it represents an idea or concept greater than the sum of
the individual pats. What is this system?
a) System of mechanisms
b) Mechanical system
c) Design system d) Expert system
115. It may be defined as the displacement per length produced in a solid and as the result of stress. How do you call this?
c) Strain
d) Stress
a) Deformation
b) Elongation
116. What is the combination of applied normal and shear stresses that produces maximum principal normal stress or minimum principal normal stress,
with a third principal stress between or equivalent to the extremes?
a) Principal shear stress
b) Principal normal stress
c) Maximum shear stress
d) Bending and shear stresses
117. How do you call a load that is applied transversely to longitudinal axis of member?
a) Combined loads
b) Concentrated load
c) Bending load
d) Distributed load
118. It is the capacity of a material to absorb energy when it is deformed elastically and then, upon unloading, to increase this energy. What is this
capacity of a material?
a) Resilience
b) Toughness
c) Rigidity
d) Ductility
119. How do you call the strain energy per unit volume required to stress a material from an unloaded state to the point of yielding?
a) Modulus of roughness b) Modulus of elasticity
c) Modulus of rigidity
d) Modulus of resilience
7
MACHINE DESIGN/SHOP PRACTICE
120. What is the ability of the material to absorb energy up to fracture?
a) Toughness
b) Rigidity
c) Resilience
d) Stiffness
121. What is the other term for the Maximum-Shear-Stress Theory, as a failure prediction theory?
b) Tresca yield criterion
a) von Mises criterion
c) Coulomb-Mohr theory
d) Modified Mohr theory
122. It is a failure prediction theory, which states that a part subjected to any combination of loads will fail (by yielding or fracturing) whenever the
maximum shear stress exceeds a critical value. How do you call this failure prediction theory?
a) Distortion-energy theory
b) Maximum-shear-stress theory
c) Internal friction theory
d) Modified Mohr theory
123. This is a theory in cyclic and impact loading, which states that damage at any stress level, is proportional to number of cycles. What is this theory
commonly called?
a) Miner’s Rule
b) Paris Power Law c) Goodman Rule d) Manson-Coffin Relationship
124. This is a lubrication where the load-carrying surfaces of the bearing are separated by a relatively thick film of lubricant, so as to prevent metal-tometal contact; and where the stability of the film can be explained by the laws of fluid mechanics. How do you call this type of lubrication?
a) Hydrostatic lubrication
b) Hydrodynamic lubrication
c) Elastohydrodynamic lubrication
d) Boundary lubrication
125. How do call the speed at which a rotating shaft becomes dynamically unstable?
a) Normal speed
b) Variable speed
c) Critical speed
d) Average speed
126. How do you call a ball bearing with race containing pronounced groove for rolling elements?
b) Conrad bearing c) Angular-contact bearing d) Cylindrical bearing
a) Crown bearing
127. This is a machining process for producing internal straight cylindrical surface or profiles, with process characteristics and tooling similar to those for
turning operations. What is this machining process?
a) Boring
b) Drilling
c) Reaming
d) Milling
128. What is a set of specification for parts, materials, or processes intended to achieve uniformity, efficiency, and a specified quality?
a) Code
b) Standard
c) Law
d) Theorem
129. This is a set of specifications for the analysis, design, manufacture, and construction of something; the purpose of which is to achieve a specified
degree of safety, efficiency, and performance or quality. How do you call this set of specifications?
a) Code
b) Standard
c) Law
d) Theorem
130. How do call the size to which limits or deviations is assigned and is the same for both members of the fit; it is the exact theoretical size?
a) Nominal size
b) Basic size
c) Maximum size
d) Minimum size
131. What is the algebraic difference between a size and the corresponding basic size?
a) Tolerance
b) Allowance
c) Deviation
d) Limit
132. What is the difference between the maximum and minimum size limits of a part?
a) Allowance
b) Tolerance
c) Deviation
d) Basic size
133. What are the stated maximum and minimum dimensions?
b) Limits
c) Nominal sizes
d) Basic sizes
a) Tolerances
134. This is a general term that refers to the mating of cylindrical parts such as bolt or a hole; it is used only when the internal member is smaller that the
external member. How do you call this?
a) Clearance
b) Interference
c) Allowance
d) Tolerance
135. What is the opposite of clearance, for mating cylindrical parts in which the internal member is larger than the external member?
d) Interference
a) Clearance
b) Allowance
c) Tolerance
136. These are compounds of metallic elements, most frequently oxides, nitrides, and carbides.
c) Ceramics
d) Alloy
a) Plastics
b) Polymers
137. What do you call a material having different properties in all directions at point in solid?
a) Isotropic material
b) Anisotropic material
c) Orthotropic material
d) Ceramic material
138. This is a principle or method that a deflection at any point in bar is equal to sum of deflections caused by each load acting separately. How do you
call this method or principle?
a) Summation Method
b) Method of balancing
c) Method of superposition
d) Shear and Moment diagram method
139. This is the accepted standard wire rope with the wires twisted in one direction to from strands and the strands twisted in opposite direction to form a
rope. How do you call this wire rope?
a) Improved plow steel wire rope
b) Regular lang lay wire rope
c) Mild plow steel wire rope
d) Long lay wire rope
140. What is a form of correction that develops on highly localized areas on a metal surface?
a) Crevice
b) Erosion
c) Galvanic
d) Apitting
141. How do you call the corrosion of iron-base-alloys?
a) Rusting
b) Crazing
c) Chalking
d) Fritting
142. Which of the following is the allowable stress that is generally used in practice for main transmitting shafts?
8
MACHINE DESIGN/SHOP PRACTICE
b) 4 000 psi
c) 6 000 psi
d) 6 500 psi
a) 8 500 psi
143. What is an equation used to determine the first critical speed of the shaft that overestimates frequency?
b) Rayleigh Equation
c) Dunkerly Equation
d) Euler Equation
a) Soderberg Equation
144. This key allows the hub to move along the shaft but prevents the rotation of the shaft. How do you call this key?
b) Feather key
c) Gibs key
d) Square key
a) Woodruff key
145. How do you call the ratio of mean diameter of coil and the coil diameter of a spring?
a) Wahl number
b) Diameter ratio
c) Spring index
d) Lead angle
146. It is a low cost spring material, suitable where service is not severe and dimensional precision is not needed. How do you call this spring material?
a) Hard drawn wire
b) helical spring wire
c) Stainless steel
d) helical tension spring wire
147. How do you call a spring material that is hard drawn (80 % reduction) but made up of high-grade steel?
b) Oil tempered wire
c) Song wire
d) Chromium-silicon wire
a) Music wire
148. It is a design approach where no catastrophic loss can occur as a result of a component failure. What is this design approach?
a) Fail-safe design approach
b) Fault free analysis approach
c) Manifest danger approach
d) Redundancy approach
149. In a lathe machine, how do you call the diameter of the largest workpiece that can be rotated in a chuck or between centers without hitting the bed?
a) Chuck diameter
b) Swing c) Distance between centers d) Spindle diameter
150. How do you call a phenomenon when two touching surfaces have a high contact pressure and when these surfaces have minute relative motion?
a) Pre-stressing
b) Friction
c) Carving
d) Fretting
151. What is this part of headstock of a lathe machine used to transmit power from the spindle?
c) Headstock spindle
d) Switch
a) Motor
b) Back gear
152. When a hot part is cooled suddenly by quenching, there is momentarily a high temperature gradient that induces a stress gradient. Some metal parts
under certain conditions crack as a result. What is this phenomenon?
a) Thermal-shock failure
b) Thermal fatigue c) Honing
d) Quenching
153. When a hot part is cooled suddenly by quenching, there is momentarily a high temperature gradient that induces a stress gradient. Some metal parts
under certain conditions crack as a result. How do you call this phenomenon?
a) Thermal-shock failure
b) Thermal fatigue c) Honing
d) Quenching
154. It is the condition of a machine element when it is completely inoperable, cannot perform its intended function adequately, or is unreliable for
continued safe use. What do you call this condition?
a) Fail-safe condition
b) Failure condition
c) Critical condition
d) Salvage condition
155. How do you call a statistical data used to identify the most likely failure modes?
b) Fault free analysis
c) Failure analysis
d) Random analysis
a) Finite element analysis
156. It is a computational method used for solving complex shapes, such as those found in machinery; replaces the complex shape with a set of simple
elements interconnected at a finite set of a specific purpose. What is this computational method?
a) Finite element analysis
b) Numerical method of analysis
c) Fault free analysis
d) Synthesis
157. It is a design approach where needed service is made apparent before catastrophic failure. How do you call this?
a) Manifest danger design approach
b) Machine element function approach
c) Failure analysis
d) Random analysis
158. It is a beam where one end is fixed and other end is free. How do you call this beam?
a) Cantilever beam
b) Continues beam c) Overhanging beam
d) Long beam
159. It is a method used to graphically visualize state of stress acting in different planes passing through a given point. What is this?
a) Mohr’s circle
b) Soderberg Criterion
c) Goodmann’s method
d) Gerber’s line criterion
160. This minimum distance is measured between the non-driving side of a tooth and the adjacent side of the mating tooth. It is the amount by which the
width of a tooth space exceeds the thickness of the engaging tooth measured on the pitch circle. What is this distance?
a) Circular pitch
b) Whole depth
c) Backlash
d) Space width
161. It is an arc of the pitch circle of a spur gear through which a tooth travels from the point of contact with the mating tooth to the pitch point. What is
this arc?
a) Arc of action
b) Arc of approach
c) Arc of recess
d) Involute curve
162. What is the intersection of the elements making up the pitch cone?
c) Apex of pitch cone
d) Root cone
a) Pitch cone
b) Cone distance
163. What do you call a type of bolt threaded on both ends and can be used where a through bolt is impossible?
c) Stud bolt
d) Carriage bolt
a) Coupling bolt
b) Machine bolt
164. To avoid excessive wear rate, what is the recommended limiting pressure for 6 x 19 rope for cast iron?
d) 500 psi
a) 200 psi
b) 400 psi
c) 300 psi
165. How do you call a type of welding where the arc is covered with a welding composition and a bare electrode wire is fed automatically?
a) Resistance welding
b) Submerged arc welding c) Induction welding
d) Spot welding
166. It is a kind of wear that occurs because of fatigue failure of the surface materials as a result of high contact stresses. What do you call this?
a) Slotting
b) Pitting
c) Involuting
d) Curving
9
MACHINE DESIGN/SHOP PRACTICE
167. It is caused by foreign matters, such as grit or metal particles, or by a failure of the oil film at low speed. How do yopu call this?
a) Auction
b) Scoring
c) Abrasion
d) Corrosion
168. It occurs when the oil films fails, but in this case, the load and speed are so high that the metal is melted and the metal is smeared down the profile.
What is this?
a) Abrasion
b) Corrosion
c) Spalling
d) Scoring
169. In gearing system, it is the advance of the tooth in the face width divided by circular pitch. What do you call this?
a) Face contact ratio
b) Speed ratio
c) Profile ratio
d) Advance ratio
170. When the pitch line speed is above 8000 fpm, the teeth should be _____.
a) Ground after hardening
b) Should be cooled in air
c) Should not be quenched after hardening`
d) none of these
171. How do you call a spring material that is hard drawn (80 % reduction) but made up of high-grade steel?
a) Music wire
b) Oil tempered wire
c) Song wire
d) Chromium-silicon wire
172. It is a spring wire with good quality for impact loads and moderately high temperatures. What is this spring material?
a) Hard drawn spring wire
b) helical spring wire
c) Chromium-silicon
d) Helical tension wire
173. It is a type of coil spring where the helical coil is wrapped into a circle forming an annular ring. How do you call this spring?
a) Volute spring
b) Motor spring
c) Hair spring
d) Garter spring
174. It is a type of spring where thin flat strip wound up on itself as a plane spiral, usually anchored at the inside end. What do you call this spring?
a) Volute spring
b) Motor spring
c) Hair spring
d) Garter spring
175. What do you call a ratio of the length of the column and the radius of gyration of the cross-sectional area about the centroidal axis?
a) Power factor
b) Contact ratio
d) Constant ratio
d) Slenderness ratio
176. A screw that requires a positive torque to lower the load, or to loosen the screw if it has been turned tight against a resistance. How do you call this
screw?
a) Power screw
b) Self screw
c) Lock screw
d) Self-locking screw
177. What is the other term used for Kennedy key?
a) Tangential key b) Normal key
c) Saddle key
d) Rollpin key
178. Which of the following device used to measure the speed accurately?
a) Dial gage
b) Dial indicator c) Speedometer
d) Tachometer
179. When the hole is smaller than the shaft, it will take pressure to put the parts together. The allowance is said to be negative and is termed as:
a) Interference of metal
b) Negative allowance
c) Negative tolerance
d) Negative fits
180. When two elastic bodies collide, which of the following laws can be used to solve for the resulting velocity?
a) Avogadro’s law
b) Conservation of momentum and conservation of energy
c) Dalton’s law of partial pressure
c) Conservation of energy
181. It is a science of motion that can be solved in terms of scalar or vector algebra. How do you cal this science?
a) Kinematics
b) Dynamics of machine
c) Engineering mechanics
d) Strength of materials
182. What is a screw fastener with a nut on it?
a) Bolt
b) Rivet
c) Fastener
d) Square screw
183. It is a type of bolt distinguished by a short portion of shank underneath the head, being square or finned or ribbed. What is this bolt?
c) Stud bolt
d) Carriage bolt
a) Coupling bolt
b) Machine bolt
184. How do you call the ratio of mean diameter of coil and the coil diameter of a spring?
c) Spring index
d) Lead angle
a) Wahl number
b) Diameter ratio
SET B
185. The combination of applied normal and shear stresses that produces maximum principal normal stress or minimum principal normal stress, with a
third principal stress between or equivalent to the extremes.
c) Maximum shear stress
d) Bending and shear stresses
a) Principal shear stress b) Principal normal stress
186. It is a load applied transversely to longitudinal axis of member.
c) Bending load
d) Distributed load
a) Combined loads
b) Concentrated load
187. It is the intensity and direction of internal force acting at given point on particular plane.
a) Load
b) Strain
c) Stress
d) Sustained load
188. It is the capacity of a material to absorb energy when it is deformed elastically and then, upon unloading, to increase this energy.
a) Resilience
b) Toughness
c) Rigidity
d) Ductility
189. It is the strain energy per unit volume required to stress a material from an unloaded state to the point of yielding.
d) Modulus of resilience
a) Modulus of roughness b) Modulus of elasticity
c) Modulus of rigidity
190. The ability of the material to absorb energy up to fracture.
a) Toughness
b) Rigidity
c) Resilience
d) Stiffness
191. The Maximum-Shear-Stress Theory, as a failure prediction theory, is also known as:
a) von Mises criterion
b) Tresca yield criterion
c) Coulomb-Mohr theory d) Modified Mohr theory
192. A failure prediction theory, which states that a part subjected to any combination of loads will fail (by yielding or fracturing) whenever the
maximum shear stress exceeds a critical value.
a) Distortion-energy theory
b) Maximum-shear-stress theory
c) Internal friction theory
d) Modified Mohr theory
10
MACHINE DESIGN/SHOP PRACTICE
193. A theory in cyclic and impact loading, which states that damage at any stress level is proportional to number of cycles.
a) Miner’s Rule
b) Paris Power Law
c) Goodman Rule
d) Manson-Coffin Relationship
194. A journal bearing where the radius of the journal is less than the radius of the bushing or bearing.
a) Fitted journal bearing
b) Clearance journal bearing
c) Partial journal bearing
d) Full journal bearing
195. A lubrication where the load-carrying surfaces of the bearing are separated by a relatively thick film of lubricant, so as to prevent metal-to-metal
contact; and where the stability of the film can be explained by the laws of fluid mechanics.
a) Hydrostatic lubrication
b) Hydrodynamic lubrication
c) Elastohydrodynamic lubrication
d) Boundary lubrication
196. A lubrication condition where non-conformal surfaces are completely separated by lubricant film and no asperities are in contact.
a) Elastohydrodynamic lubrication
b) Boundary lubrication
c) Hydrodynamic lubrication
d) Hydrostatic lubrication
197. A speed at which rotating shaft becomes dynamically unstable.
a) Normal speed
b) Variable speed
c) Critical speed
198. A ball bearing with race containing pronounced groove for rolling elements.
a) Crown bearing
b) Conrad bearing
c) Angular-contact bearing
d) Average speed
d) Cylindrical bearing
199. A machining process for producing internal straight cylindrical surface or profiles, with process characteristics and tooling similar to those for
turning operations.
a) Boring
b) Drilling
c) Reaming
d) Milling
200. A machining operation for all types of metallic and nonmetallic materials and is capable of producing circular parts with straight or various profiles.
b) Turning
c) Drilling
d) Milling
a) Boring
201. A set of specification for parts, materials, or processes intended to achieve uniformity, efficiency, and a specified quality.
a) Code
b) Standard
c) Law
d) Theorem
202. A set of specifications for the analysis, design, manufacture, and construction of something; the purpose of which is to achieve a specified degree of
safety, efficiency, and performance or quality.
a) Code
b) Standard
c) Law
d) Theorem
203. The algebraic difference between the maximum limit and the corresponding basic size.
a) Fundamental deviation
b) Upper deviation
c) Lower deviation d) Tolerance
204. A material having different properties in all directions at point in solid.
a) Isotropic material
b) Anisotropic material
c) Orthotropic material
d) Ceramic material
205. A principle or method that a deflection at any point in bar is equal to sum of deflections caused by each load acting separately.
a) Summation Method
b) Method of balancing
c) Method of superposition
d) Shear and Moment diagram method
206. A failure prediction theory in which failure is caused by the elastic energy associated with shear deformation.
a) Maximum-shear-stress theory
b) Distortion-energy theory
c) Maximum-normal-stress theory
d) Internal friction theory
207. When a lathe tool bit is burns, it means that the:
a) Speed is too low
b) Material is too hard
208. What does the designation AISI 4130 for a steel mean?
a) Molybdenum-Chromium, 0.3 % carbon
c) Molybdenum-nickel, 0.0 % carbon
c) Speed is too fast
d) Material cannot be cut
b) Plain carbon, 0.41 % carbon
d) Manganese, 0.13 % carbon
209. Which of the following is not a method of non-destructive testing of steel, casting and forging?
a) Radiography
b) Ultra sound
c) Magnetic particles
d) Chemical analysis
210. It is a spring wire with good quality for impact loads and moderately high temperatures. What is this spring material?
a) Hard drawn spring wire
b) helical spring wire
c) Chromium-silicon
d) Helical tension wire
211. What do you call a ratio of the length of the column and the radius of gyration of the cross-sectional area about the centroidal axis?
d) Slenderness ratio
a) Power factor
b) Contact ratio
d) Constant ratio
212. A screw that requires a positive torque to lower the load, or to loosen the screw if it has been turned tight against a resistance. How do you call this
screw.
d) Self-locking screw
a) Power screw
b) Self screw
c) Lock screw
213. How do you call the product of the length and diameter of the bearing?
a) Projected area
b) Shearing area
c) Compressive area
214. Devise used to measure an accurate speed:
a) Speedometer
b) Dial Indicator
c) Tachometer
d) Cross-sectional area
d) Dial Gauge
215. When the hole is smaller than shaft, it will take pressure to put the parts together. The allowance is said to be negative and is termed as:
a) Negative tolerance
b) Negative allowance
c) Negative fits
d) Interference of metal
11
MACHINE DESIGN/SHOP PRACTICE
216. When two elastic bodies collide, which of the following laws can be used to solve for the resulting velocity?
a) Dalton’s law
b) Avogadro’s law
c) Conservation of energy
d) Conservation of momentum and conservation of energy
217. The ability of a metal to be deformed considerably without rapture is called as:
a) Plasticity
b) Ductility
c) Malleability
d) All of these
218. Permanent deformation or strain may occur without fracture:
a) Malleability
b) Elasticity
219. A mechanism that usually do the indexing in a machine tool:
a) Universal chuck
b) Slotter
c) Ductility
d) Plasticity
c) Dividing head
d) Indexing
220. The product of the resultant of all forces acting on a body and the time that the resultant acts:
a) Angular impulse
b) Angular momentum
c) Linear Impulse d) Linear momentum
221. Which of the following is not a structural class of steel?
a) Low carbon steel
b) Tool and die steel
c) High chrome alloy steel d) High strength low allow steel
222. Poisson’s ratio is the ratio of which of the following?
a) Shear strain to compressive strain
c) Lateral strain to longitudinal strain
223. All are associated with the grade of steel except:
a) SAE 43xx
b) SAE 13xx
b) Elastic limit to compressive strain
d) Elastic limit to proportional limit
c) SAE 10xx
224. A property of material that relates the lateral strain to the longitudinal strain:
a) Stress
b) Strain
c) Poisson’s ratio d) Strength
225. The maximum stress to which a material may be subjected before failure occurs.
c) Endurance limit
a) Ultimate strength
b) Ultimate stress
226. Hypoid gear is a special type of gear like:
a) Worm gear
b) Spur gear
c) Herringbone gear
d) SAE 74xx
d) Tensile stress
d) Bevel gear
227. The considered maximum safe center distance of sprockets because very long center distance causes catenary tension in the chain.
a) 70 pitches
b) 80 pitches
c) 60 pitches
d) 50 pitches
228. Cold working of steel plates make the metal:
a) Tougher
b) More ductile
c) Harder
d) More malleable
229. Recommended best cutting angle of drill for work on steel or cast iron is:
a) 48 degree
b) 63 degrees
c) 59 degrees
d) 50 degrees
230. One of the causes of spur gear tooth breakage is the unbalanced load on one end of the tooth that results in higher stresses than when the load is
evenly distributed. To minimize this problem, the face width “b” should not be greater than the thickness (or pitch) of the tooth. In the absence of
test values, the following can be a guide:
a) 2.5pc < b 4pc
b) 2pd < b < 4 pd
c) 2.5pd < b < 4pd
d) 2pc < b < 4 pc
231. The three moment equation may be used to analyse:
b) Continuous beam
c) Composite beam
a) Tapered column
232. Ordinary steel begins to loose strength and elasticity significantly at about:
b) 800 to 900 oF
c) 750 to 850 oF
a) 900 to 1000 oF
d) Axially end loaded beam
d) 600 to 700 oF
233. Clearance to a new boiler installation to the existing or old plant building should follow a minimum clearance of ________ between top of the boiler
proper and the ceiling as stated in the PSME Code.
a) 2000 mm (max)
b) 1000 mm (max)
c) 2130 mm (max)
d) 2150 mm (max)
234. For a high corrosion resistant stainless steel, what minimum chromium content is required?
a) 8 %
b) 4.3 %
c) 1.1 %
d) 5.8 %
235. Name the type of chuck commonly used for holding workpiece in a lathe operation. Example: 3-jaw universal chuck, 4-jaw independent chuck.
a) Magnetic jaw chuck b) 2-jaw independent chuck
c) 8-jaw universal
d) Combination
236. V-belt operate efficiently at speed of about:
a) 4500 fpm
b) 4400 fpm
c) 4200 fpm
d) 3600 fpm
237. What type of gear is used for high speed operation?
b) Spur
c) Bevel
d) Worm
a) Helical
238. In a pair of gears, it is the plane perpendicular to the axial plane and tangent to the pitch surface.
c) Pitch circle
d) Pitch point
a) Pitch
b) Pitch plane
239. Killed steel is always associated with:
a) Silicon
b) Manganese
240. The usual ratio of water to soluble oil used as cutting fluid.
a) 50 % water to 50 % oil
b) 2 water to 1 oil
c) Phosphorous
d) Sulfur
c) 3 water to 1 oil
d) 4 to 80 water to 1 oil
12
MACHINE DESIGN/SHOP PRACTICE
241. How do you call a type of welding whereby a wire or powder from the nozzle of a spray gun is fused by a gas flame, arc or plasma jet and the
molden particles are projected in form of a spray by means of compressed air or gas?
a) Electro-slug building
b) Electro-beam welding
c) Plasma arc welding
d) Metal spray welding
242. Which of the following does not belong to foundry or metal casting shop?
a) Shake-out machine
b) Molding machine
c) Core making
d) Forging machine
243. Which of the following is an unsafe act or condition in operating a lathe machine?
b) Wearing a canvas apron
a) Wearing demin pants and safety shoes
c) Operating with safety gloves
d) Wearing safety goggles and hearing aid
244. It is a type of welding in which the weld metal is a mixture of aluminum powder and a metal oxide powder which is ignited in a crucible.
a) Thermit welding
b) Gas welding
c) Electric arc welding
d) Metal spray welding
245. These are polymers which, at room temperature, can undergo large deformation under a load and return back to their original shape upon release of
load.
a) Elastomers
b) Thermosetting polymers
c) Thermoplastics
d) Meso-polymers
246. Which of the following is the 4th most commonly used metal in the world?
a) Zinc
b) Steel
c) Aluminum
d) Copper
247. The most widely used material for machine elements because of its properties of high strength, high stiffness, durability, and relative ease of
fabrication.
a) Zinc
b) Steel
c) Aluminum
d) Copper
248. In a pressure vessel, the ratio of minimum strength of joint to the strength of solid joint is known as:
a) Efficiency
b) Performance Factor
c) Joint Efficiency d) Relative Strength
249. In a pressure vessel, the usual factor of safety may be taken as:
a) 2
b) 4
c) 3
d) 5
250. It is the permissible variation of the size of a dimension.
a) Tolerance
b) Fits
c) Limits
d) None of above
251. If there is no fit, a liberal tolerance of the order of ______ in machining work could be permitted.
b) ± 0.010
c) ± 0.09
d) ± 0.05
a) ± 0.020
252. A tolerance where the size of a part is permitted to be either larger or smaller than the given dimension.
a) Bilateral
b) Unilateral
c) lateral
d) None of these
253. A tolerance where the size of a part may be larger only, or smaller only, than the given dimension.
b) Unilateral
c) Lateral
d) None of these
a) Bilateral
254. If two principal stresses are zero, the state of stress is:
b) Uni-axial
c) Mono-axial
d) Triaxial
a) Biaxial
255. If one principal stress is zero, the state of stress is:
a) Biaxial
b) Uni-axial
c) Mono-axial
d) Triaxial
256. If all the principal stresses have finite values, the system is:
d) Triaxial
a) Biaxial
b) Uni-axial
c) Mono-axial
257. Under theories of failure, for static loading of ductile material, the design stress is equal to:
a) Yield stress/Factor of safety
b) Ultimate stress/Factor of safety
c) Factor of safety/Yield stress
d) Endurance strength/Factor of safety
258. An old rule of thumb for transmission shafting is that the deflection should not exceed _______ of length between supports.
b) 0.03 inch per foot
c) 0.02 inch per foot
d) 0.04 inch per foot
a) 0.01 inch per foot
259. In general, for machinery shafts, the permissible deflection may be closer to:
c) 0.002 inch per foot
d) 0.03 inch per foot
a) 0.02 inch per foot
b) 0.01 inch per foot
260. A helical gear of 10 inches pitch diameter has a helix angle of 30o, and there are 30 teeth. Find the value of the normal circular pitch.
a) 0.9069 inch/tooth
b) 0.6909 inch/tooth
c) 0.6096 inch/tooth
d) 0.9906 inch/tooth
Solution: Pc =
πD π (10 )
=
= 1.0472 inches / tooth
T
30
(
)
Pcn = Pc cos ψ = 1.0472 cos 30o = 0.9069 inch / tooth
261. A parallel helical gear set was a 17-tooth pinion driving a 34-tooth gear. The pinion has a right-hand helix angle of 30o, a normal pressure angle of
20o, and a normal diametral pitch of 5 teeth/in. Find the axial circular pitches.
a) 1.2566 inches/tooth
b) 1.6625 inches/tooth
c) 1.6526 inches/tooth
d) 1.6256 inches/tooth
Solution: Pc =
Pcn
0.62832
=
= 0.72552 inch / tooth
cos ψ cos 30o
Pa =
13
Pc
0.72552
=
= 1.2566 inches / tooth
tan ψ tan 30o
MACHINE DESIGN/SHOP PRACTICE
262. What is this part of headstock of a lathe machine used to transmit power from the spindle?
c) Headstock spindle
d) Switch
a) Motor
b) Back gear
263. When a hot part is cooled suddenly by quenching, there is momentarily a high temperature gradient that induces a stress gradient. Some metal parts
under certain conditions crack as a result. What is this phenomenon?
a) Thermal-shock failure
b) Thermal fatigue c) Honing
d) Quenching
264. How do you call an axial distance that a screw advances in one turn or revolution?
b) Circular pitch
c) Pitch
a) Lead
265. What is a screw fastener with a nut on it?
a) Bolt
b) Rivet
c) Fastener
d) Axial pitch
d) Square screw
266. It is a type of bolt distinguished by a short portion of shank underneath the head, being square or finned or ribbed. What is this bolt?
a) Coupling bolt
b) Machine bolt
c) Stud bolt
d) Carriage bolt
267. How do you call a large wood screw that is used to fasten machinery and equipment to a wooden base?
a) Lag screw
b) Wood screw
c) Log screw
d) Square screw
268. It is a low cost spring material, suitable where service is not severe and dimensional precision is not needed. How do you call this spring material?
a) Hard drawn wire
b) helical spring wire
c) Stainless steel
d) helical tension spring wire
269. Used for permanent fits, are similar to involute splines except that the pressure angles 14.5o
a) Separation load
b) Stub serrations
c) Spline shaft
d) Involute serrations
270. Are used as couplings or in additions to other couplings where, in case of overload, there is a danger of injury to machines o to materials in process.
b) Shear pin
c) Flange coupling
d) King pin
a) Involute serrations
271. A coupling that transmits power via the frictional forces induced by pulling the flanges each over slotted tapered sleeves.
a) Flange coupling
b) Ribbed compression coupling
c) Rigid Coupling
d) Flanged compression coupling
272. A coupling used for absorbing some shock and vibration that may appear on one shaft and preventing the occurrence of reversed stresses
caused of the shaft deflecting at the coupling.
b) Flexible Coupling
c) Flange Coupling
d) None of these
a) Rigid Coupling
273. For thrust bearings, the speed at the moderate operating condition is
a) 50 < Vm < 200 fpm
b) 50 < Vm < 220 fpm
c) 50 < Vm< 250 fpm
274. Experience suggests that the most economical designs are obtained for a belt speed of
a) 4000 to 4500 fpm
b) 2000 to 3000 fpm
c) 3000 to 4000 fpm
275. For leather belts, recommended speed is
a) 6000 to 7500 fpm
b) 2000 to 3000 fpm
276. The ability of the material to absorb energy up to fracture.
a) Toughness
b) Rigidity
d) 50 < Vm < 290 fpm
d) 4000 to 5000 fpm
c) 7000 to 8000 fpm
d) 4000 to 5000 fpm
c) Resilience
d) Stiffness
277. The combinations of two or more materials, usually consisting of fiber and thermosetting polymer.
a) Brittle materials
b) Composite materials
c) Polymers
d) Ceramics
278. The product of the length and diameter of the bearing is called:
a) Projected area
b) Shearing area
c) Compressive area
d) Cross-sectional area
279. In motor vehicles, it is a very common practice to use:
c) Cone clutch
a) Multiple clutch
b) Hydraulic clutch
280. Which gauge is used to check internal threads?
a) Plug gauge
b) Ring gauge
c) Thread plug gauge
d) Single plate clutch
d) Thread ring gauge
281. When outside diameter of a job is turned in relation to the internal hole, the job should be held:
a) In three-jaw chuck
b) On the lathe mandrel
c) On face plate
d) Between centers
282. Shaper operation which is shaping the given stock and having the excess material remain with a tolerable allowance for finishing.
a) Roughing
b) Finishing
c) Angular cutting
d) Contouring
283. The property of a material that measures the degree of plastic deformation sustained at fracture.
c) Ductility
d) Brittleness
a) Toughness
b) Stiffness
284. The product of the resultant of all forces acting on a body and the time that the resultant acts:
a) Angular impulse
b) Angular momentum
c) Linear Impulse
285. Which of the following is not a structural class of steel?
a) Low carbon steel
b) Tool and die steel
286. Poisson’s ratio is the ratio of which of the following?
a) Shear strain to compressive strain
c) Lateral strain to longitudinal strain
287. All are associated with the grade of steel except:
c) High chrome alloy steel
d) Linear momentum
d) High strength low allow steel
b) Elastic limit to compressive strain
d) Elastic limit to proportional limit
14
MACHINE DESIGN/SHOP PRACTICE
d) SAE 74xx
a) SAE 43xx
b) SAE 13xx
c) SAE 10xx
288. A property of material that relates the lateral strain to the longitudinal strain:
d) Strength
a) Stress
b) Strain
c) Poisson’s ratio
289. The phenomenon of continuous stretching under load even if the stress is less than the yield point.
a) Elasticity
b) Ductility
c) Plasticity
d) Creep
290. A machinery operation whereby done with the accurately fastened has a reciprocating (forward and backward) motion and tool head is stationary.
c) Turning
d) Reaming
a) Shaping
b) Planing
291. The maximum stress to which a material may be subjected before failure occurs.
c) Endurance limit
d) Tensile stress
a) Ultimate strength
b) Ultimate stress
292. Hypoid gear is a special type of gear like:
a) Worm gear
b) Spur gear
c) Herringbone gear
d) Bevel gear
293. The usual ratio of water to soluble oil used as cutting fluid.
a) 50 % water to 50 % oil
b) 2 water to 1 oil
c) 3 water to 1 oil
d) 4 to 80 water to 1 oil
294. The considered maximum safe center distance of sprockets because very long center distance causes catenary tension in the chain.
a) 70 pitches
b) 80 pitches
c) 60 pitches
d) 50 pitches
15
JCSF ENGINEERING REVIEW CENTER
# 2 Alvaran’s Apartment, Purok 7, Halang
City of Calamba, Laguna
MACHINE DESIGN AND SHOP PRACTICE (Refreshers Trivia # 5A)
Prepared by: Jose R. Francisco, PME
September 2012
MULTIPLE CHOICE QUESTIONS
Select the best answer from each of the following questions. On the answer sheet provided, shade the box that corresponds to your choice. Strictly no
erasures allowed
1. Hacksaw blades are made of what materials?
a) tool steel
b) tungsten alloy steel
c) high speed steel
d) any of the above
2. A hacksaw blade with 24 TPI is best suitable for cutting which of the following materials?
a) tubing
b) brass and copper
c) sheet metal over 18 gage
d) any of the above
3. Which of the following is a “must” for all hard hacksaw blades?
a) it has a hard back and flexible teeth
b)it has a flexible back and hard teeth
c) it has the entire blade hardened
d) it will only fit a solid frame hacksaw
4. In how many positions can a hacksaw blade be placed in a frame?
a) two positions
b) one position
c) four positions
d) three positions
5. Files are divided into two general classes. How are these classified?
a) rough and smooth
b) single-cut and double-cut
c) large and small
d) flat shapes and round shapes
6. The term “set” of a saw best defines what?
a) to set properly in the frame
b) alternate teeth are turned slightly to left and right o make cutting slot slightly wider than the thickness of the blade
c) the teeth have been case-hardened for better cutting
d) the teeth are set evenly apart
7. All hard hacksaw blades are best suited for work on which of the following?
a) brass
b) cast iron
c) tool steel
d) any of the above
8. Which of the following is the best instrument for measuring thousandths of an inch?
a) caliper
b) micrometer
c) tachometer
d) pyrometer
9. A hacksaw blade with 34 teeth per inch should be used for cutting which of the following materials?
a) brass
b) heavy stick
c) cast iron
d) thin wall building
10. How is the hacksaw blade should be placed in the frame?
a) the teeth pointing forward
b) the teeth pointing backward
c) one end looser than the other end
d) the teeth facing in any
direction
11. Which of the following is the usual procedure when cutting a long thin piece of metal?
a) turn the blade upside down in the frame
b) turn the blade at right angles to the frame
c) use a blade with fewer teeth per inch
d) set the blade in the frame with the teeth facing toward you
12. A hacksaw blade with 18 teeth per inch is best suited for cutting material(s)?
a)solid stock
b) aluminum
c) cast iron
d) any of the above
13. What is the used of coolant in the power hacksaw when cutting materials?
a) absorb the heat of friction
b) prevent the blade from overheating
c) prevent the blade form losing its temper
d) all of the above
14. What is used for finishing a piece of work to size with a file?
a) double-cut fine-tooth file
b) mill file
c) single-cut fine-tooth file
d) crossing file
15. The process of finishing off a piece of metal with a real smooth finish,
a) draw – filling
b) mill – filling
c) side – filling
d) flat – filling
16. How do you call a small piece of metal clogged between the teeth on a file?
a) cogs
b) pins
c) flats
d) bumps
17. Which of the following described as the “safe edge” of the file?
a) the end opposite the handle
b) the edge with no teeth
c) the one with the handle
d) none of the above
18. The best procedure when filling a piece of metal in a lathe is to take:
a) short even strokes
b) long fast strokes
c) long slow strokes
d) short fast strokes
19. Which of the following information is necessary when ordering a file?
a) size(length)
b) type of teeth
c) shape
d) all of the above
20. Which of the following is the best file to be used when finishing sharp corners or slots and grooves?
a) mill file
b) knife file
c) square
d) jeweler’s file
21. How is “eleven – sixteenth” of an inch expressed in decimal?
a) 0.6785
b) 0.6875
c) 0.7685
d) 0.6578
22. What is the approximate distance of the marking in a micrometer barrel?
a) 0.025” apart
b) 0.0025” apart
c) 0.250” apart
d) 2.50” apart
23. Which of the following is the effect if the lathe is put into back gear?
a) go backwards of the same speed
b) faster
c) slower
d) at a slower speed backwards
24. The work should be head with ______ when using a drill press.
a) the hand
b) a vise or clamp
c) a pair of pliers
d) gloves on
25. What is normally used in drilling a hole in a piece of work held in a lathe chuck?
a) compound rest
b) tailstock and drill chuck c) cross-feed
d) headstock
26. Copper is annealed by heating to a cherry red color and:
a) dousing in cold water
b) dousing in oil
c) cooling slowly in air
d) dousing in hot water
27. What is the main purpose of “annealing” a metal?
a) to make the metal harder
b) to make the metal softer
c) to make the metal harder medium-hard
d) to make the metal shiny
28. The process of “tempering” is to make a metal what?
a) harder
b) less brittle
c) softer
d) more britle
29. What is the minimum diameter of a piece of round stock necessary to make a square key ¾” on a side?
a) 1.5”
b) 1.0”
c) 1.06”
d) 0.75”
30. A scriber is made from what materials?
a) carbon steel
b) tool steel
c) cold-rolled steel
d) hot-rolled steel
31. Before applying layout blue on a piece of metal, it must be:
a) roughened
b) cleaned
c) heated
d) cold
32. A drill bi has how many flutes?
a) 4 flutes
b) 2 flutes
c) 3 flutes
d) no flutes
33. The alignment of coupling faces can be checked by which process?
a) using an inside micrometer
b) inserting a thermocouple
c) inserting a feeler gage between the coupling faces at various point around the circumference
d) rotating and measuring to nearest permanent fitting
34. A piece of cast iron held against an emery wheel will give off what/
a) dull yellow sparks
b) red sparks
c) bright shiny sparks
d) no sparks
35. When cutting material in a lathe, the softer the material being cut, the tool bit should have:
a) more top rake
b) double top rake
c) less top rake
d) any of the above
36. After grinding a tool bit, the cutting edge should be:
a) case-hardened
b) stoned w/an oil stone
c) rubbed w/emery cloth
d) rubbed w/crocus cloh
37. When turning a piece of round metal in a lathe, the front clearance should be smaller for:
a) large-diameter cutting
b) cutting angles
c) small-diameter cutting
d) none of the above
38. When cutting material in a lathe, the harder the material being cut, the tool bit should have:
a) more side rake
b) more top rake
c) less side rake
d) no side rake
39. What is the primary purpose of knurling?
a) smooth material
b) roughen material
c) polish material
d) sharpen material
40. What do you call the process of removing the sharp edges from a piece of stock?
a) knurling
b) planning
c) chamfering
d) turning
41. At what speed that carbon steel drills should be operated?
a) speed greater than that when using a high-speed drill
b) speeds less than that when using a high-speed drill
c) the same speed as what when using a high-speed drill
d) none of the above
42. A specific method of zinc galvanizing in which parts are tumbled in zinc dust at high temperatures.
a) sheradizing
b) super finishing
c) polishing
d) pickling
43. Abrasion of parts against wheels or belts coated with polishing compounds.
a) sheradizing
b) super finishing
c) polishing
d) pickling
44. A super fine grinding operation used to expose nonfragment crystalline base metal.
a) sheradizing
b) super finishing
c) polishing
d) pickling
45. A process in which meta; is dipped in dilute acid solutions to remove dirt grease and oxides.
a) sheradizing
b) super finishing
c) polishing
d) pickling
46. A hot – dip or electroplate application of tin to steel.
a) tin – plating
b) metal spraying
c) organic finishes
d) lapping
47. A fine grinding operation used to obtain exact fit and dimensional accuracy.
a) tin – plating
b) metal spraying
c) organic finishes
d) lapping
48. The covering of surfaces with an organic film of painting, enamel or lacquer.
a) tin – plating
b) metal spraying
c) organic finishes
d) lapping
49. The spraying of molten metal onto a product. Methods include metallizing, metal powder spraying and plasma flame spraying..
a) tin – plating
b) metal spraying
c) organic finishes
d) lapping
50. Application of a thin phosphate coasting on steel to improve corrosion resistance.
a) parkenizing
b) honing
c) hard surfacing
d) galvanizing
51. This process is known as bonderizing when used as a primer for paints.
a) parkenizing
b) honing
c) hard surfacing
d) galvanizing
52. A grinding operation using stones moving in a reciprocating pattern. Leaves a characteristics cross – hatch pattern.
a) parkenizing
b) honing
c) hard surfacing
d) galvanizing
53. The creation (by spraying, plating, fusion wielding, or heat treatment) of a hard metal surface in a softer product.
a) parkenizing
b) honing
c) hard surfacing
d) galvanizing
54. A zinc coating applied to low carbon steel to improve corrosion resistance. The coating can be applied in a hot dip bath, by electroplating or by dry
tumbling (sheradizing).
a) parkenizing
b) honing
c) hard surfacing
d) galvanizing
55. The electro – deposition of a coating onto the workpiece. Electrical current is used to drive ions in solution to the part. The workpiece is the cathode
in the electrical circuit.
a) electroplating
b) calorizing
c) burnishing
d) buffing
56. The diffusing of aluminum into a steel surface, producing an aluminum oxide that protects the steel from high – temperature corrosion.
a) electroplating
b) calorizing
c) burnishing
d) buffing
57. How do you call the process of fine grinding or peening operation designed to leave a characteristic pattern on the surface of the workpieces?
a) electroplating
b) calorizing
c) burnishing
d) buffing
58. A fine finishing operator, similar to polishing, using a very fine polishing compound.
a) electroplating
b) calorizing
c) burnishing
d) buffing
59. Rotating parts in a barrel filed with an abrasive or non abrasive medium. Widely used to remove burrs, flash, scale and oxides.
a) abrasive cleaning
b) calorizing
c) barrel finishing
d) anodizing
60. An electroplating – acid bah oxidation for aluminum and magnesium. The workpiece is the anode in the electrical circuit.
a) abrasive cleaning
b) calorizing
c) barrel finishing
d) anodizing
61. Shooting sand(i.e. sand blasting), steel grit, or steel shot against workpieces to remove casting sand, scale and oxidation.
a) abrasive cleaning
b) calorizing
c) barrel finishing
d) anodizing
62. What is the other term of barrel finishing?
a) abrasive cleaning
b) calorizing
c) barrel finishing
d) anodizing
63. Brittle materials produce discrete fragments, known as:
a) chip breaker grooves
b) discontinuous chips
c) non-segmented chips
d) type-two chips
64. Ductile materials from long, helix – coiled string chips known as:
a) continuous chips
b) discontinuous chips
c) segmented chips
d) type – one chips
65. Often ground in the cutting tool face to cause long chips to break into shorter, more manageable pieces,
a) chip breaker grooves
b) discontinuous chips
c) non – segmented chips
d) type – two chips
66. What is the typical chip thickness ratio?
a) 0.50
b) 0.75
c) 0.25
d) 1.00
67. The angles at which the tool meets the workpiece is characterized by:
a) true rake cycle
b) clearance angle
c) relief angle
d) wedge angle
68. Which of the following is the sum of the rake, clearance and wedge angles?
a) 90 deg.
b) 180 deg
c) 45 deg
d) 75 deg
69. What is the relative velocity difference between the tool and the workpiece?
a) cutting speed
b) chip velocity
c) shear velocity
d) rake velocity
70. How do you call the velocity of the chip relative to the tool face?
a) cutting speed
b) chip velocity
c) shear velocity
d) rake velocity
71. How do you call the velocity of the chip relative to the workpiece?
a) cutting speed
b) chip velocity
c) shear velocity
d) rake velocity
72. Which of the following is the primary parameter affecting the cutting energy requirement?
a) compressive stress
b) shear stress
c) torsional stress
d) bending stress
73. The energy expended per unit volume removed is known as:
a) specific cutting energy
b) metal removal rate
c) cutting horsepower
d) absolute cutting energy
74. A plain carbon steel with approximately 0.9 to 1.3% carbon, which has been hardened and tempered
a) carbon tool steel
b) high speed steel
c) low speed steel
d) medium speed steel
75. Contains tungsten or chromium and retains its hardness up to approximately 600 C.
a) carbon tool steel
b) high speed steel
c) low speed steel
d) medium speed steel
76. Cast nonferrous tools are brittle but can be used up to approximately:
a) 1000 C
b) 925 C
c) 1500 C
d) 750 C
77. Which of the following is produced through powder metallurgy from nonferrous metals?
a) sintered carbides
b) ceramic tools
c) diamonds
d) cast nonferrous
78. Ceramic tools operate:
a) below 2000 F
b) below 2200 F
c) above 2000 F
d) above 2200 F
79. Which of the following is manufactured from aluminum oxide have the same expected life as carbide tools but can operate at speeds from two to
three times higher? They operate below 1100 C.
a) shintered carbides
b) ceramic tools
c) diamonds
d) cast nonferrous
80. Which of the following are used in specific case, usually in finishing operations.
a) shintered carbides
b) ceramic tools
c) diamonds
d) cast nonferrous
81. Used as finishing operation since very fine and dimensionally accurate surface can be produced.
a) grinding
b) snagging
c) honing
d) lapping
82. Describes very rough grinding such as that performed in foundries to remove gates, fins and risers from castings.
a) grinding
b) snagging
c) honing
d) lapping
83. Grinding in which very little material, 0001 to 0.005 in is removed.
a) grinding
b) snagging
c) honing
d) lapping
84. Which of the following is not a measuring device?
a) orsat analyzer
b) thermometer
c) micrometer caliper
d) dvider
85. A plain carbon steel with approximately 0.9 to 1.3% carbon which has been hardened and tempered
a) carbon tool steel
b) cast nonferrous
c) high-speed steel
d) diamond
86. Carbon tool steel can be given a good edge, but is restricted to use below:
a) 400 to 600 F
b) 300 to 400 F
c) 700 to 800 F
d) 800 to 1000 F
87. Which of the following contains tungsten or chromium and retains its hardness up to approximately 1100 F, a property know as red hardness:
a) ceramic tools
b) diamonds
c) high speed steel
d) carbon tool steel
88. Cast nonferrous tools are brittle but can be used up o approximately:
a) 1700 F
b) 2200 F
c) 2000 F
d)600 F
89. They are produced through powder metallurgy from nonferrous metals.
a) diamonds
b) cast nonferrous
c) ceramic tools
d) sintered carbides
90. Sintered carbide operate at cutting speeds how many times as fast as HSS tools:
a) 2 to 5
b) thrice
c) 5 to 7
d) twice
91. Which of the following is manufactured from aluminum oxide have he same expected life as carbide tools but can operate at speeds from two to
three times higher?
a) ceramic tools
b) high speed steel
c) diamonds
d) carbon tool steel
92. Soluble in the presence of high temperature iron used in specific cases, usually in finishing operations.
a) ceramic tools
b) diamonds
c) high speed steel
d) aluminum
93. Percent of the heat developed in cutting is due to friction between the tool and the workpiece is:
a) approximately 50%
b) approximately 10%
c) approximately 25%
d) approximately 75%
94. Which of the following is used o reduce friction, remove heat, remove chips and protect against corrosion.
a) water vapor
b) carbon
c) air
d) cutting fluid
95. Which of the following is a good heat remove, but it promote rust?
a) air
b) kerosene
c) carbon dioxide
d) water
96. Addition of ________ to water produces an efficient, inexpensive cutting fluid that does not promote rusting:
a) sal soda
b) kerosene lubricants
c) straight cutting oils
d) air
97. It reduces friction and do not cause rust but are less efficient of heat removal that water.
a) sal soda
b) kerosene lubricants
c) straight cutting oils
d) air
n
98. Taylor’s equation relates cutting speed v and tool life T for particular combination of tool and workpiece, VT = constant. This equation is also
known as:
a) flank wear
b) nose failure
c) crater wear
d) tool life
99. After any cutting or standard grinding operation, the surface of a workplace will consist of:
a) smear metal
b) ultrafinishing
c) superfinishing
d) centerless grinding
100. A method does not require clamping, chucking, or holding round workpieces.
a) centerless grinding b) laser machining
c) chemical milling
d) ulrafinishing
JCSF Engineering Review Center
Just Come and See your Future
ME Development Program – Machine Design: Refresher Trivia 5B
19.
INSTRUCTION: Select the correct answer for each of the following questions.
Mark only one answer for each item by shading the box corresponding to the
letter of your choice on the answer sheet provided. STRICTLY NO ERASURES
ALLOWED. Use pencil No. 1 only.
20.
21.
1. It is plane between mating teeth or the amount which a tooth space
exceed the thickness of an engaging tooth is called_____.
a. Backlash
c. Clearance
b. Pitting
d. Space
2. For ordinary turning drilling and milling on low strength steel the cutting
fluid applied have soluble oil with consistency of 1 part oil to ____ parts
water.
a. 10 to 30
c. 10 to 20
b. 10 to 15
d. 5 to 10
3. The cutting tool used the shaper are similar to turning tools of ____
machine.
a. Boring
c. Broaching
b. Lathe
d. Planer
4. Which of the following is not a mandrel?
a. Contraction
c. Expanded
b. Extended
d. Taper
5. It is axially located rectangular groove in a hub and shaft.
a. Cutter pin set
c. Flute
b. Key seat
d. Set screw point
6. Machine tool used for laying straight lines on metal surfaces made of
sharp tool steel is called____.
a. Divider
c. Plain scriber
b. Hermaphrodite caliper d. Trammel
7. In Machine Shop had forging operation of lengthening a piece of stock
while reducing the cross sectional area of work is called:
a. Bloating
c. Draining
b. Upsetting
d. Spreading
8. An act of cutting out a piece of metal at desired shape and size is
known as:
a. Blanking
c. Dinking
b. Broaching
d. Slitting
9. It is a chromium steel tape in AISI-SAE designation.
a. 10XX
c. 25XX
b. 50XX
d. 40XX
10. Stiffness is the materials ability to _____ deformation under stress.
a. Planar
c. Resist
b. Starter
d. Non – planar
11. Wood pattern in the foundry is normally constructed out of.
a. Dried sap wood
c. Hard wood
b. Kiln dried wood
d. Scrap wood
12. It is a petroleum by product used as electrodes in an electric arc
furnace melting operation.
a. Anthracite coke
c. Bituminous coke
b. Foundry coke
d. Graphite electrodes
13. In drilling soft materials use cutting angle as low as 40 degrees but for
extremely hard material up to ____ degrees is recommend.
a. 80
c. 75
b. 70
d. 65
14. Opposite directional forces equal in magnitude and parallel is called
_____.
a. Non coplanar
c. Centro
b. Couple
d. Coplanar
15. The function of the clutch in the machine tool is :
a. Lowering the drive speed
b. To disconnect or connect the shaft at will the drive
c. Alignment of drive shaft
d. To insure that two shafts line up at high speed
16. The most known lubricants being utilized in whatever category of
load and speed are oil, air, grease and dry lubricants like:
a. Bronze
c. Lead
b. Silicon
d. Graphite
17. Molybdenum chromium nickel steel designation:
a. SAE 48XX
c. SAE 43XX
b. SAE 56XX
d. SAE46XX
18. Imaginary formed by the intersection of the flanks of a thread when
extended is called ____ beyond the root.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
1
a. Sharp crest
c. Sharp root
b. Root apex
d. Root crest
Steels containing large amounts of mild nickel and chromium:
a. Carbon steel
c. Stainless steel
b. Alloy steel
d. Cast steel
Which of the following is not a strength property of materials?
a. Tensile strength
c. Rocking strength
b. Fatigue strength
d. Torsional strength
Instrument used to analyze the composition of metals:
a. Spectrometer
c. Radiometer
b. Profilometer
d. Ultimate analyzer
A machining operation whereby the tool reciprocates and the feed is
stationary is called:
a. Shaping
c. Reaming
b. Planning
d. Turning
Stainless steel is obtained principally by the use of which alloying
elements?
a. Chromium
c. Nickel
b. Carbon
d. Tungsten
Rack gears have identical term / definition as to the ____ of the spur
gear.
a. Pitch circle
c. Pitch diameter
b. Addendum
d. Clearance
Safety features that must be placed and maintained at machine black
smith welding and foundry shops called
a. Safety goggles
b. Safety notices
c. Safety notices in markers / boards
d. Walkway shops
Common defects encountered in the foundry shop steel casting
operation and also in welding practices.
a. Blow / pin holes
c. Cracks
b. Parting line
d. Cold shot
A mechanism which usually does the indexing in a machine tool is
called.
a. Dividing head
c. Indexing
b. Universal chuck
d. Slotter
Hydrodynamic brakes is the major type of
a. Air brake
c. Fluid brake
b. Electric brake
d. Spot brake
Which of the following types of brakes are also changed while
replacing brake lining?
a. Brake shoes
c. Shoe rivets
b. Shoe spring
d. Block brake
A cone formed by elements which are perpendicular to the elements
of the pitch cone at the large end.
a. Cone distance
c. Back cone
b. Root cone
d. Cone center
The product of the mass and the linear velocity of a body.
a. Angular impulse
c. Angular momentum
b. Linear impulse
d. Linear momentum
Arch of the pitch circle through which a tooth travels from the point of
contact with the mating tooth to the pitch point of gear.
a. Arc of access
c. Arch of action
d. Arc of relief
b. Arc of approach
A machine member which is used to connect shafts and to
disconnect t them at will:
a. Coupling
c. Collar
b. Clutch
d. Universal joint
In the selection of wire rope, Lang ray means the wires and strands
are twisted:
a. In same direction c. In any direction
b. In opposite direction d. In along direction
Should two equal and opposite collinear forces is added to the forces
already equilibrium, which of the following statement is true?
a. Unbalanced moment is maintained
b. Equilibrium is maintained
c. Equilibrium is distributed
d. It creates an unbalanced situation
Ferrous metals contain a relatively large amount of:
a. Carbon
c. Manganese
b. Phosphorus
d. Sulfur
Of the following metals, which will respond to heat treatment?
a. Cast iron
c. Wrought iron
b. Medium carbon steel
d. Low carbon steel
38. Creep is the term used in referring to the:
a. Elongation before yield point
b. Maximum stress of brittle materials
c. Fatigue limit of ductile materials
d. Continuous increase in the strain or deformation at any
material subjected to stress
39. Splines are used when:
a. The power to be transmitted is high
b. The torque is high
c. The speed is high
d. Axial relative motion between shaft and hub is necessary
40. Improves hardenability economically, resistance to corrosion strength
at high temperatures:
a. Manganese
c. Copper
b. Aluminum
d. Chromium
rd
th
41. In the SAE identification code of steel shafting the 3 and 4 digits
represents the content of:
a. % manganese on the steel
b. % alloy elements
c. % carbon contents
d. % chromium in the steel
42. In the usual spur gearing, the
a. Pitch circle and base circle are the same
b. Working depth includes the clearances
c. Tooth outline are usually involute curves
d. Tooth outline are always cycloidal curves
43. A relatively high temperatures and low rates of strains, structures will
perform better if material is:
a. Fine grained
b. Course grained
c. Their behavior is independent of grain
d. All of the above
44. It is Nickel steel type in AISI or SAE designation:
a. 15xx
c. 33xx
b. 40xx
d. 23xx
45. Modulus of rigidity of steel member is:
a. A function of the length and width
b. Equal to the modulus of elasticity divided by one plus Poison’s
ratio
c. Defined as the unit shear stress divided by the unit shear
deformation
d. Defined as the length divided by the moment of inertia
46. Gear tooth cut inside a cylinder or ring is called ____ gear.
a. Ninter
c. Rack
b. Ring
d. Internal
47. The progressive change in position of ____ is called motion.
a. Component
c. Couple
b. Link
d. Mass
48. Fast process of analyzing all elements and chemical components for
steel casting is
a. Carbon analyzer
c. Pyrometer
b. Spectrometer
d. Wet analyzer
49. Too much ____ in a flat belt operation tend to cause excessive wear
slippage and may burn the belt.
a. Play
c. Slack
b. Stiffness
d. Tightness
50. It is a low cost bearing used worldwide for automobile or low
horsepower motor applications. It is made of thin coating of _____
over flat metal strip.
a. Babbitt
c. Cadmium brass
b. Lead
d. Thin
51. Which of the following processes that hydraulic fluid acts as transfer
media?
a. Electron beam machining
b. Electro discharge machining
c. Iron beam machining
d. Water jet machining
0
52. Point angle of 135 on drill is used for
a. Bake like hard rubbers and fibrous plastic
b. Hard steels and nickel alloys
c. Thin sheets metals
d. B and C
53. A machine shop equipment than can flatter horizontally, vertically or
angular plane called:
a. Drill machine
c. Power saw
b.
Shaper machine
d. Welding machine
54. This particular cutting tool material could with stand cutting
0
temperature of 1800 F and higher at cutting speed beyond those
possible with other cutting tool materials called:
a. Carbide grade
c. Cubic boron nitride
b. Ceramic
d. Titanium carbide
55. A lathe machine threading mechanism is called
a. Anvil
c. Reverse gear and lever
b. Changed stud gear d. Spindle gear
56. The five principal parts of the shaper are the table, tools slide, base,
ram and ____.
a. Apron
c. Column
b. Drive motor
d. Vise
57. Web is a part of the drill and is usually thicker ______.
a. Nearing the shank c. Close to the future
b. Beside the land
d. At the tip portion.
58. An act of cutting out a piece of metal at a desired shape and size is
known as ______.
a. Blanking
c. Broaching
b. Dinking
d. Slitting
59. In a cutting tool the cutting end can also be generally called
a. Back rake
c. End cutting edge
b. Nose
d. Side rake
60. Relief angle of single point cutting mild steel cast iron and other
average work as recommended should be in the ranges of _____
degrees for high speed tools.
a. 5 to 7
c. 8 to 12
b. 10 to 5
d. 12 to 16
61. In drilling soft materials use cutting angle as low as 40 degrees but
for extremely hard material up to ____ degrees is recommend
a. 80
c. 75
b. 70
d. 65
62. What factors can modify the recommended cutting speed of known
work piece?
a. Depth of cut
b. Modify the shape of the cutting tools
c. Rough cutting of work piece
d. Use correctly shape of the cutting tools
63. A cutting tool angle between the side cutting edge and the plane
perpendicular to direction of feed travel is _______.
a. Lead
c. Side cutting edge
b. Side rake
d. Side relief
64. The tool bit made of tool blank consists of face, nose, shank and
_____.
a. Cutting edge
c. Cutting angle
b. Nose
d. Round nose
65. The effective face width of a helical gear divide by the axial pitch.
This is sometimes called face overlap.
a. Angle overlap
c. Axial overlap
b. Contact overlap
d. Helical overlap
66. The lathe carriage part that bridge across the bed to carry the cross
slide and the tool rest.
a. Apron
c. Automatic feed
b. Compound rest
d. Saddle
67. For mass production of casting it is generally cheaper to use: _____
pattern for longer life.
a. Aluminum
c. Brass
b. Metal
d. Wooden
68. Strain or _____ is a change in geometry / shape of the body due to
action of a force on it.
a. Bending stress
c. Deformation
b. Shear stress
d. Stress
69. What is the recommended cutting speed range for bronze in fpm?
a. 60/70
c. 80/60
b. 100/110
d. 200/250
70. What is the tool used in making wood pattern in the foundry shop?
a. Band saw
c. Hammer
b. Drill machine
d. Saw and chisel
71. Which of the following tools does not belong to the group?
a. Divider
c. Hermaphrodite caliper
2
b.
Double VEE block d. Trammel
88. An iron in which most of the carbon is chemically combined with the
iron.
a. Cast iron
c. Gray iron
b. White iron
d. Malleable iron
89. Which of the following material is made by reduction of iron ore in a
blast furnace?
a. Wrought
c. Cast
b. Pig
d. Ingot
90. In greater quantity this element is harmful to the ferrous metal.
a. Sulfur
c. Silicon
b. Zinc
d. Aluminum
91. Bearing surface that completely surrounds the journal is also called
____.
a. Offset bearing
c. Full bearing
b. Centrally loaded bearing
d. Abbitt bearing
72. A lathe machine threading mechanism is called_____.
a. Anvil
c. Reverse gear and lever
b. Changed stud gear d. Spindle gear
73. The impact force introduced to cause the metal to flow in a shaped
mold according to the shape to dies made.
a. Hardness
c. Swaging
b. Spinning
d. Toughness
74. Which of the following materials that improve red hardness?
a. Cobalt
c. Copper
b. Columbium
d. Boron
75. What processes of enlarging hole by means of a reamer to produce
a smooth and accurate hole?
a. Drilling
c. Boring
b. Finishing
d. Reaming
76.
92. The type of bolt commonly used in the construction that is threaded
at both ends.
a. Stud bolt
c. Acme thread bolts
b. Hex bolt
d. Square threaded bolt
Which of the following is not part of a lathe machine?
a. Carriage
c. Headstock
b. Tailstock
d. Fan
93. A machine which is used to finish internal and external surfaces by
the use of a cutter, which has a series of cutting edges or teeth.
a. Broaching machine
b. Lathe machine
c. Milling machine
d.
Planer
77. Which of the following metals is nonmagnetic?
a. Cast iron
c. Manganese steel
b. Cast iron
d. Wrought iron
78. A drill bit has how many flutes?
a. 4
c. 3
b. 2
d. 1
94. A machine used in shaping metal by means of abrasive wheel or the
removal of metals with an abrasive is called:
a. Planer
b. Power saw
c. Shaper
d. Grinding machine
79. The passage way of molten metal into the mould cavity is known as
____.
a. Piping system
c. Gating system
b. Entry system
d. Delivery system
95. Improves the machinability of alloy of steels but affects different
alloys differently:
a. All of these
b. Selenium
c. Vanadium
d. Lead
80. What device used for holding the work piece on a lathe?
a. Chucks
c. Carriage
b. Anvil
d. Catch plates
0
81. What process of heating iron base alloys to approximately 40 C
above the critical temperature range followed by cooling to below
that range in steel air at ordinary temperature?
a. Normalizing
c. Annealing
b. Tempering
d. Quenching
96. It is general practice to use the following allowable stresses, 4000 psi
for the main transmitting shaft and 8500 psi for small, short,
countershafts. For lineshaft carrying pulley it is____ psi.
a. 8500
b. 7000
c. 6000
d. 6500
97. Which process does not belong to the group?
a. Resistance welding
b. Soldering
c. Hardening
d. Brazing
82. A tool for checking the flatness of plane surfaces to tenths of
thousands of a centimeter.
a. Planimeter
c. Micrometer
b. Caliper
d. Profilometer
83. What is the most expensive metal?
a. Silver
c. Bronze
b. Platinum
d. brass
98. When the hole is smaller than the shaft, it will take force to put the
parts together, the allowance is said to be negative and is called:
a. Interference
b. Clearance
c. Allowance
d. Toughness
84. Which of the following area is considered as the heart of the machine
shop?
a. Mass production area
c. Foundry area
b. Assembly area
d. Quality control area
85. Which of the following area where metal is melted to form them into a
bloom, billet and etc?
a. Welding area
c. Tool and die area
b. Foundry area
d. Mass production area
99. The process of increasing the carbon content to the surface of steel
by exposing it to hot carbonaceous material above the transformation
o
o
temperature of 1650 F to 1750 F.
a. Carbonitriding
b. Case hardening
c. Carburizing
d. Hardening
100. The internal stresses existing in a wielded connection are:
a. Not relieved by heat treatment
b. Not relieved when the welded is peened
c. May be relieved when the weld is peened
d. Relieved by x – ray analysis
86. Most effective alloying element for reducing brittlement of steel
silicon.
a. Manganese
c. Molybdenum
b. Silicon
d. Nickel
87. Which of the following materials is known as binding element?
a. Boron
c. Cobalt
b. Lithium
d. Mercury
3
JCSF Engineering Review Center
JCSF ENGINEERING REVIEW CENTER
2nd Floor Santos-Causing Building, National Highway
Halang, City of Calamba, Laguna
MACHINE DESIGN/SHOP PRACTICE TRIVIA (Refresher Trivia 6)
Prepared by: Jose R. Francisco, PME
September 2012
MULTIPLE CHOICE QUESTIONS
Select the best answer from each of the following questions. On the answer sheet provided, shade the box that corresponds to your choice. Strictly no
erasures allowed
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
Type of gear that transmits power at an angle.
a) bevel
b) helix
c) herringbone
d) spur
Which of the following gasket material is not used for high temperature?
a) asbestos
b) plastic nylon
c) rubberized
d) wool
A plane perpendicular to the gear axis.
a) normal plane
b) pitch plane
c) plane of rotation
d) radius of gyration
Specification of molybdenum alloy.
a) SAE 3XXX
b)SAE 4XXX
c) SAE 5XXX
d) SAE 6XXX
A ______chain is an assembly of line and joint.
a) dynamic
b) kinetic
c) sprocket
d) static
The recommended means of supporting the chuck during the mounting procedure to the lathe spindle is to use:
a) Crane
b) Jack
c) Overhead
d) Ratchet
Too much _____ in a flat belt operation tend to cause excessive wear slippage and may burn the belt.
a) load
b) lack
c) usage
d) tightness
It is a chromium steel tape in AISI-SAE designation.
a) 10XX
b) 25XX
c) 50XX
d) 40XX
For large speed ratio and large sprocket utilized it is recommended cast _______material since the large sprocket teeth are having fewer engagement.
a) alloyed steel
b) heat treated steel
c) iron
d) malleable iron
Roller baring is utilized on ________ carrying capacity and is better than ball bearing in this condition.
a) heavy load
b) high temperature load
c) low load
d) reversing load
To enhance mechanical properties, fabrication characteristic or any other attributes of steel, some elements are added in melting in specific ranges or
minimum aside from carbon and generally termed:
a) alloy steel
b) AISI steel
c) Bessemer steel
d) SAE steel
Materials having thermal expansion of about 10 times higher than those of metals and has more heat generated during machining is:
a) aluminum
b) asbestos
c) plastic
d) PVC
To hold to minimum, the axial direction of deflection/movement, a separate thrust berating or preloaded bearing capable of absorbing considerable load
is required. The type of bearing to use is a _________ bearing.
a) deep grove ball
b) double row angular contract
c) tapered roller bearing
d) wide type self-aligning
Pulley made of ____ordinarily is 45 to 55% less in weight and 2.35 and 2.70% less slippage compared with ________ pulley.
a) iron/steel
b) steel/iron
c) wood/iron
d) wood/steel
To avoid in scoring in the bearing surface and the shaft due to contamination/absorption on the fine dirt in the bearing during operation/lubrication the
bearing material to apply should have good _______ properties.
a) anti-scoring
b) resistance comfortability
c) corrosion resistance
d) embeddability
What do impact test measure?
a) compactness
b) ductility
c) plasticity
d) toughness
Corresponding piping color for alkaline.
a) blue
b) green
c) red
d) violet
Prepared tool bit will now consist of face, nose and
a) cutting tool
b) shank
c) sharp tool
d) tool edge
This is an alloy in bronze casting that assists lubrication and in itself a lubricant:
a) lead
b)manganese
c) phosphorus
d) tin
For lone sprocket chain life the speed range of __________fpm is recommended,
a) 1200-1400
b) 1500-1600
c) 1800-2000
d) 2000-2100
All stainless steel type is SAE designation except:
a) 92XX
b)300XX
c)304 XX
d) 515 XX
It is white metal with good oxidation and corrosion resistance. This has also good electrical magnetic properties.
a) aluminum
b) copper
c) nickel
d) titanium
It is a molybdenum steel-tape in AISI-SAE designation.
a) 44 XX
b) 45 XX
c) 50 XX
d) 51 XX
Cutting lubricants used in drilling, reaming and tapping for hard spots in cast iron.
a) dry
b) kerosene
c) soda water
d) turpentine
In a _______ design, the lead of a single thread is equal to the pitch.
a) bevel gear
b) bolt
c) helical gear
d) hypoid gear
A type of chisel used in cutting of keyways, square corners or slots.
a) cape
b) diamond head
c) flat
d) round
The maximum recommended ideal number of teeth to use for bigger sprocket is:
a) 120
b) 127
c) 132
d) 143
The teeth on the outer ring surface is called the external gear:
a) developed
b) flank
c)gear
d)involute
For large speed ratio and large sprocket utilized it is recommended cast ___________ material since the large sprocket teeth are having fewer
engagement.
a) alloyed steel
b) heat treated steel
c) iron
d) malleable iron
Roller bearing is utilize on ___________carrying capacity and is better than ball bearing in thus condition,
1
JCSF Engineering Review Center
a) heavy load
b) high temperature load
c) low load
d) reversing load
31. To enhance mechanical properties, fabrication characteristics or any other attributes of steel, some elements are added in melting specific ranges or
minimum aside from carbon and generally termed _______..
a)alloy steel
b) AISI steel
c) Bessemer steel
d) SAE steel
32. Materials having thermal expansion of about 10 times higher than those of metals and has more heat generated during machining is:
a) aluminum
b) asbestos
c) plastic
d) PVC
33. To hold to minimum, the axial direction of deflection/movement, a separate thrust bearing or preloaded bearing capable of absorbing considerable load
is required. The type of bearing to use is a _______ bearing.
a) deep grove ball
b) double row angular contract
c) tapered roller bearing
d) wide type self-aligning
34. Pulley made of ____ordinarily is 45 to 55% less in weight and 2.35 and 2.70% less slippage compared with ________ pulley.
a) iron/steel
b) steel/iron
c) wood/iron
d) wood/steel
35. A plane perpendicular to the gear axis.
a) normal plane
b) pitch plane
c) plane of rotation
d) radius of gyration
36. The minimum value of numerical combined shock and fatigue factor to be applied in every case to be computed bending moment of the shaft is:
a) 2.0
b) 1.75
c) 1.5
d) 1.3
37. What is the other name given to short shafts on machines?
a) spindles
b) head shafts
c) core shafts
d) all of these
38. The other name given o a line shaft is:
a) countershaft
b) main shaft
c)long shaft
d) head shaft
39. The speed at which center of mass will be equal the deflecting forces on the shaft; the shaft with its attached bodies will then vibrate violently, since the
centrifugal force changes its direction as the shaft turns in:
a) nominal speed
b) critical speed
c) relative speed
d) mean speed
40. For ordinary steel, the modulus of elasticity usually falls between _______million pounds.
a) 20 to 31
b) 35 to 45
c) 20 to 35
d) 25 t 30
41. The modulus of elasticity for metals in compression is usually taken as that in:
a) tension
b) bearing
c) yield
d) ultimate
42. Which of the following is the ratio of moment and stress?
a) strain
b) section modulus
c) contraction
d) passions ratio
43. What is the flexural stress when of a symmetrical cross-section beam when the vertical shear is maximum?
a) infinity
b) zero
c) maximum
d) minimum
44. The riveted joints in ASME Code has a design surface compressive stress _____ higher than the design tensile stress.
a) 70%
b) 60%
c) 35%
d) 50%
45. What is the ratio of the minimum strength of joint to the strength of solid joint in the pressure vessel?
a) efficiency
b) relative strength
c) performance factor
d) joint efficiency
46. What is the usual factor of safety for a pressure vessel?
a) 4
b) 1.5
c) 3
d) 5
47. It is the permissible variation of the size.
a) tolerance
b) limits
c) fits
d) none of these
48. Considering that there is no fit, what is the permissible liberal tolerance in machining work?
a) ± 0.010
b) ± 0.090
c) ± 0.020
d) ± 0.050
49. Which of the following is a tolerance where the size of a part may be larger only, or smaller only, than the given dimension.
a) unilateral
b) lateral
c) bilateral
d) none of these
50. A tolerance where the size of a part is permitted to be either larger or smaller than the given dimension.
a) unilateral
b) lateral
c) bilateral
d) none of these
51. Which of the following is he basis for ASA fits?
a) basic number system
b) basic hole system
c) basic size system
d) unit system
52. When the hole is smaller than the shaft, it will take force on pressure to put the cold parts together. In such case the allowance is negative. Which of the
following terms is appropriate for such allowance?
a) negative fits of metals
b) interference of metals
c) positive fits of shafts
d) intangible fits
53. What is the direction of the predominant surface pattern?
a) smoothness
b) waviness
c) lay
d) roughness
54. Which of the following is not a type of bolt
a) stud bolt
b) steel bolt
c) machine bolt
d) coupling bolt
55. It is a locking device that is used to maintain pressure between threads of the bolt and nut.
a) gasket
b) lock washer
c) lock nuts
d) filler
56. What is the large wood screw used to fasten machinery and equipment.
a) lag screw
b) loss screw
c) wood screw
d) cross screw
57. What is the minimum length of contact in a tapped hole or cast iron?
a) 1.7 D
b) 1.5 D
c) 1.2 D
d) 2.1D
58. It is the ratio of the mean diameter of coil over the coil diameters.
a) Wahl factor
b) spring index
c) coil ratio
d) lead scale
59. What is the overall length of the spring when it is compressed until all adjacent coils touched?
a) free length
b) solid length
c) compressed length
d) expansion length
60. It is the length of a coil spring under no load.
a) compressed length
b) free length
c) solid height
d) none of these
61. In general, the steel springs are made of relatively of relative high carbon steel usually.
a) 5%
b) less than 0.5%
c) more than 0.5%
d) 7.5%
62. It is a low cost spring material suitable where service is not severe and dimensional precision is not needed.
a) helical spring wire
b) stainless steel
c) hard drawn wire spring
d) copper
63. What is the hard drawn (80 %reduction)spring wire made of high carbon steel?
a) oil tempered
b) music wire
c) tension wire
d) chromium wire
64. Which of the following wires with good quality and is used for impact loading?
a) hard drawn wire
b) song wire
c) helical spring wire
d) chromium silicon wire
65. When heat-treated wire is coiled cold, it should be stress relieved for bending stress and after cooling it is heated at some:
o
o
o
o
b) 600 F
c) 700 F
d) 500 F
a) 400 F
2
JCSF Engineering Review Center
66. Which of the following is not a function of spring?
a) absorbs energy
b) source of potential energy c) measure of weight
d) measure thickness
67. Which of the following is the type of spring made in the form of dished washer?
a) air spring
b) bellevile spring
c) volute spring
d) motor spring
68. What is the type of failure due to unstability?
a) buckling
b) slenderness ratio
c) Stability
d) Euler’s failure
69. What type of formula that is bust applied to a very slender column?
a) column formula
b) slenderness formulas
c) moment formulas
d) Euler formula
70. If two principal stresses is zero, the state of stress is:
a) biaxial
b) mono-axial
c) uniaixial
d) triaxial
71. What do you call the system that have finite values of principal stresses?
a) triaxial
b) uniaxial
c) mono-axial
d) biaxial
72. A screw that requires positive torque to lower the load, or to loosen the screw if it has been turned tight against a resistance.
a) self locking screw
b) lock screw
c) self screw
d) power screw
73. What is the rotating member used in transmitting power?
a) shaft
b) counter shaft
c) axle
d) washer
74. Which of the following is the approximate density of a fat rubber belt?
3
3
3
3
b) 0.0135 lb/in
c) 0.045 lb/in
d) 0.0465 lb/in
a) 0.055 lb/in
75. A toothed wheel whose tooth elements are straight and parallel to the shaft axis or used to transmit motion and power between parallel shafts.
a) helical gear
b) spur gear
c) worm gear
d) bevel gear
76. The breaking strength of oak-tanned beltings varies from 3 to more than:
a) 5 ksi
b) 6 ksi
c) 7 ksi
d) 9 ksi
77. Experience suggests that the most economical designs are obtained for a belt speed of:
a) 6000 to 7500 fpm
b) 3000 to 5000 fpm
c) 3500 to 4700 fpm
d) 5000 to 1000 fpm
78. The tension in the belt due to centrifugal force increasing rapidly above:
a) 2500 fpm
b) 3000 fpm
c) 3500 pm
d) 4000 fpm
79. For leather belts, recommended speed is:
a) 6000 to 7000 fpm
b) 5000 to 6000 fpm
c) 7000 to 8000 fpm
d) 4500 to 56000 fpm
80. The recommended initial tension of the belt is:
a) 75 lb/in of width
b) 7 lb/in of width
c) 71 lb/in of width
d) 0 lb/in of width
81. Two shafts at right angles to each other may be connected b what arrangement?
a) half turn
b) quarter turn
c) ¾ turn
d) one turn
82. The minimum number of teeth on a smaller sprocket for low speed is:
a) 12
b) 21
c) 17
d) 14
83. The minimum number of teeth on a smaller sprocket speed is:
a) 17
b) 21
c) 12
d) 14
84. The minimum number of teeth on a smaller sprocket for high speed is:
a) 21
b) 24
c) 12
d) 14
85. The resultant of a pair of equal forces but opposite in direction is called:
a) concurrent
b) couple
c) non-concurrent
d) resultant
86. The helical and herringbone gear teeth cut after heat treatment should have a hardness in the range of 210/300BHN. The pinion gear teeth hardness
on the other hand, ideally/normally should be at _______ BHN.
a) 250/320
b) 350/380
c) 400
d) 340/350
87. SAE 51XXX belongs to the ___________ steel family.
a) carbon
b) chromium
c) manganese
d) nickel
88. In itself, it is a lubricant and usually one of the important elements in casting non-ferrous metals like bronze, for example:
a) antimony
b) Babbitt
c) lead
d) zinc
89. Gasket material, which should avoid hot liquid/steam application.
a) Asbestos fiber
b) Nylon fiber
c) Rubberized
d) wool
90. A ridge of uniform section in the form of helix cut around the circumference of a cylinder and advancing along the axis.
a) thread roots
b) screw threads
c) helix thread
d) chamfers
91. Cast iron flywheels are commonly designed with factor of safety of:
a) 10 to 13
b) 10 to 14
c) 10 to 12
d) 8 to 13
92. Class of material exhibiting decreased electrical conductivity with increasing temperature.
a) aluminum
b) metals
c) p-type semiconductors
d) n-type conductors
93. The welding made along edges of two parallel plates is called:
a) groove joint
b) edge joint
c) fillet joint
d) corner joint
94. Not part and in fact should not used in the steel melting process:
a) coke
b) zinc
c) silicon
d) aluminum
95. Role of thumb in calculating the equipment foundation mass should be ______ times the weight of the machinery it is supposed to support.
a) 3-5
b) 3-9
c) 3-6
d) 2-4
o
96. The strength of non-ferrous alloys is at maximum at room temperature while that of ferrous metal has a maximum strength at ____ F
a) 400
b) 450
c) 1200
d) 350
97. The ratio of stress acting on a elastic substance to the decrease in volume per unit volume.
a) bulk modulus
b) elastic limit
c) modules of resilence
98. The normal helix angles in helical gear is recommended in the range of _____degrees,
a) less than 18
b) 15 to 25
c) 20 to 35
99. Type of bolt commonly used in construction that is threaded in both ends.
a) stud bolt
b) hex bolt
c) acne threaded bolts
100. It is rigid piece serves to transmit force from a piece another piece or to cause/control motion
a) follower
b) cam motion
c) crank
3
d) modules of elasticity
d) 20 to 30
d) square threaded bolt
d) link
MACHINE DESIGN/SHOP PRACTICE
JCSF ENGINEERING REVIEW CENTER
# 2 Alvaran’s Apartment, Purok 7, Halang
City of Calamba, Laguna
MACHINE DESIGN AND SHOP PRACTICE
(Refreshers Trivia # 7 for September 2011 Board Examination)
Prepared by: Jose R. Francisco, PME
September 2011
MULTIPLE CHOICE QUESTIONS
Select the best answer from each of the following questions. On the answer sheet provided, shade the box that corresponds to your choice. Strictly no
erasures allowed.
1.
A cantilever beam of uniform rectangular cross-section carries an electric motor weighing 40 kg at a distance of 30 cm from the fixed end. The
2
allowable design bending stress in the beam is 400 kg/cm . Determine the depth of the beam, in cm, if depth is twice the width.
a) 3.30 cm
b) 3.30 mm
c) 2.20 cm
d) 2.20 mm
40 kg
Solution:
h
30 cm
sf =
b
(40 kg )(30 cm )⎛⎜ h ⎞⎟
Mc
=
I
⎝ 2 ⎠ = 12(40 )(30 ) = 6(40 )(30 ) = 1800 = 400
2bh 2
b3
b(2b )2
3
bh
12
1
⎛ 1800 ⎞ 3
b=⎜
⎟ = 1.65 cm
⎝ 400 ⎠
2.
A bar of 12 mm diameter is subjected to an axial load of 50kN. Find the magnitude of the induced stress.
A. 244.90 MPa
B. 442.09 MPa
C. 294.42 MPa
Solution: σ t =
3.
t=
(3 ft )(12 inches / ft ) = 2 min utes
18 inches / min
time =
Length of cut
2 inches
=
= 0.167 min
(
)(
Cutting rate
24 teeth / rev 100 rev / min )(0.005 inch / tooth )
5
If the length of a 15 mm diameter bar is 1 m and the modulus of elasticity of the material of the bar is 2 x 10 MPa, find the elongation of the bar if it is
subjected to 60kN axial load.
A. 3.7mm
B. 2.7mm
C.0.7 mm
D. 1.7mm
δ=
Solution:
6.
F 50 × 10 3
=
= 442.09MPa
π
A
× 12 2
4
How long will it take to mill a ¾ inch by 2 inches long keyway in a 3 inches diameter shafting with a 24-tooth cutter turning at 100 rpm and 0.005 inch
feed per tooth?
a) 0.136 min
b) 0.196 min
c) 0.167 min
d) 0.106 min
Solution:
5.
D. 424.90 MPa
With the arc welding rate of 18 inches per minute, how long will it take to weld ½ inch thick plate by 3 ft long seam.
a) 3 minutes
b) 2 minutes
c) 1.5 minutes
d) 4 minutes
Solution:
4.
h = 2b = 2(1.65) = 3.30 cm
(
)
(
FL
60 × 103 (1000)
= 1.7 mm
=
AE ⎛ π
⎞
⎜ × 152 ⎟ 2 × 105
⎝4
⎠
)
Due to application of load, a 10mm diameter bar elongates 2 mm from its original length of 1 m. If the Poisson’s ratio for the material of the bar is 0.3,
find the change in diameter of the bar.
A. 4 × 10
−3
mm
B. 5 × 10
−3
C. 6 × 10
mm
1
−3
mm
D. 7 × 10
−3
mm
MACHINE DESIGN/SHOP PRACTICE
⎛ change in diameter ⎞
⎜
⎟
⎜ original diameter ⎟
lateral strain
⎝
⎠
Poisson’s ratio, µ =
=
⎛ change in length ⎞
longitudinal strain
⎜
⎟
⎜ original length ⎟
⎝
⎠
Solution:
change in diameter = 6 × 10
Therefore:
7.
−3
⎛ change in diameter ⎞
⎜
⎟
⎜
⎟
10
⎝
⎠
hence; 0.3 =
⎛ 2 ⎞
⎟
⎜⎜
3⎟
⎝ 1 × 10 ⎠
mm
A compression member of FG 200 C.I has to support a load of 750kN. Using a ratio of 2 for the outer to inner diameter and a factor of safety of 6,
based on ultimate strength, find the outer diameter of rod using Suc = 630 MPa for FG 200 C.I.
A. 65 mm
B. 55mm
Solution:
for the area of cross section of machine member,
[
C. 130 mm
]
π
(2d )2 − d 2 = .75πd
4
A=
Then, σc =
d = 55.05 mm rounded to 55 mm
8.
F Suc
,
=
A F.S
D. 110 mm
∴ 0.75 • π • d 2 =
(750 ×10 )× 6
3
630
outer diameter = 2d = 55mm x 2 = 110 mm
A shaft is supported with two bearings and is subjected to a radial load of 70 kN. Find the length of bearings if permissible bearing pressure is 1.5 MPa
and diameter of the shaft id 100 mm.
A. 235 mm
B. 335 mm
C. 465 mm
D. 345 mm
Solution:
load on each bearing
Permissible bearing pressure =
projected area of each bearing
Load on each bearing = 35 kN
Projected area of each bearing = diameter of the shaft x length of bearing
Substituting
1.5 =
9.
35000
,
100L
L = 233.33 mm modified to 235 mm
What is the pitch of an American Standard Screw Threads with designation 12-28 UNF?
a) 0.083 inch
b) 0.0357 inch
c) 0.5 inch
Solution: p =
d) 0.75 inch
1
1
1
=
=
= 0.0357 inch
n No. of threads per inch 28
10. A helical coil spring has mean coil diameter of 24 mm and a wire diameter of 3 mm. If the shearing stress is 413.6 MPa, how much load can it support?
a) 195.33 N
b) 145.33 N
c) 154.33 N
d) 165.33 N
Solution:
C=
D m 24
=
=8
d
3
F=
Kw =
(
4C − 1 0.615 4(8) − 1 0.615
+
=
+
= 1.184
4C − 4
C
4(8) − 8
8
)
πd 3 s s
π(3 mm )3 413.6 N / mm 2
=
= 154.33 N
8K w D m
8(1.184 )(24 mm )
11. If the length of a 50 mm diameter steel rod is 1000 mm, what maximum axial load should act on the steel rod such that deformation in axial direction is
not more than 0.5 mm?
A. 202.24 kN
B. 808.96 kN
C. 505.26 kN
D. 303.85 kN
Solution:
FL
,
δ=
AE
for steel, E=206 GPa
∴ P=
(0.5)⎛⎜ π × 502 ⎞⎟(206 × 103 )
⎝4
⎠
1000
= 202.24kN
12. A hollow steel shaft 3 m long transmits 25 kN.m torque. If the total angle of twist is design not to exceed 2° and permissible shear stress is equal to 60
MPa, find the cross sectional area of the hollow shaft.
2
2
2
2
B. 10535 mm
C. 30135 mm
D. 30351 mm
A. 10335 mm
Solution:
using
Using τ =
θ=
TL
,
JG
16Td o
(
π d o4
− di4
∴
)
,
(
(
)× 3000
)⎤⎥ × (0.8 × 10 )
2× π
25 × 106
=
180
⎡⎛ π ⎞ 4
4
⎢⎜ ⎟ d o − d i
⎣⎝ 32 ⎠
∴ 60 =
(
(
)
16 25 × 106 d o
π × 2.7356 × 108
d o4 − d i4 = 2.7356 × 108 mm 4
5
⎦
)
di = 58.91 mm ≅ 59 mm
2
d o = 128.91 mm ≅ 129 mm
MACHINE DESIGN/SHOP PRACTICE
A=
For cross-sectional area,
(
) (
)
π 2
π
d o − d i2 = 129 2 − 592 = 10335mm 2
4
4
13. A tension bar is subjected to an axial pull of 30 kN. The bar is hollow with inner diameter 0.6 times the outside diameter. Find the diameters if material
is 30C8 steel with Sut=500 MPa, Sy=330MPa and F.S on yielding is 3.
A. 20 mm, 12 mm
B. 24 mm, 15 mm
C. 18 mm , 11 mm
D. 25 mm, 15 mm
Sd =
Solution:
Sy
F.S
Sd =
330MPa
= 110MPa
3
=
(
F
π 2
d o − di2
4
)
∴ 110 =
,
30 × 103
(
)
2⎤
π⎡ 2
d o − 0.6d o2 ⎥
⎢
4⎣
⎦
d o = 23.29 ≅ 24mm
d i = 0.6d o = 0.6 × 24 = 14.4 ≅ 15mm
14. Determine the maximum power a solid shaft of 60 mm can transmit at 240 rpm if permissible shear for the material is 90MPa.
A. 120 kW
B. 120 W
C. 96 W
D.96 kW
Solution: τ =
16T
πD
3
T=
,
τ × π × D3 90 × π × 603
= 3817.035 N.m
=
16
16 × 1000
P=
π
π ⎛ 3817.035 ⎞
×T× N =
×⎜
⎟ × 240 = 96 kW
30
30 ⎝ 1000 ⎠
15. A propeller shaft in a ship is 400 mm in diameter. The allowable working stress in shear is 50 MPa and allowable angle of twist is 1° per 15 diameter
length. If G = 85 GPa, determine the maximum torque that the shaft can transmit.
A. 621 kN.m
B. 721 kN.m
C. 521 kN.m
D. 421 kN.m
Solution:
π
32 × (T )
180
=
∴
15 × 400 π × 4004 × 85 × 103
1o ×
θ
32T
=
15D π × D 4 × G
TL
,
θ=
JG
(
)
T = 621 kN.m
16. A shaft has a single disc weighing 800 lb mounted on it, 5 inches from the left bearing and 15 inches from the right bearing. If the shaft diameter is 1.58
6
inches and assuming that the modulus of elasticity is 30 x 10 psi. Determine the lowest critical speed of the shaft, neglecting the shaft weight.
a) 2607.44 rpm
b) 2406.74 rpm
c) 2076.44 rpm
d) 2706.44 rpm
W = 800 lb
π D 4 π (1.58 )
I=
=
= 0.3059 in.4
64
64
4
Solution: Solving for the I,
Solving for the lowest critical speed,
ωcr =
36 E I L g
=
a 2 b2 W
N cr =
(
36 30 x 106
) ( 0.3059 )( 20 )( 32.2 ) = 217.44 rad / s
( 5) (15) (800 )
30 ( 217.44 )
2
30 ωcr
=
π
π
2
= 2 076.44 rpm
5”
Rayleigh Method/Equation
a)
Single mass system: ωcr =
g
δ
Where,
ω = angular speed, rad/s
δ = deflection, m
g = acceleration due to gravity = 9.8066 m/s
b)
For Round Steel Shaft of Uniformly Distributed Weight: ωcr =
384 E I ⎛ 12 g ⎞
5 L3 ⎜⎝ W ⎟⎠
γ = 0.28 lb/in.3 (for steel)
⎛ π D4 ⎞
384 30 x 106 ⎜
⎟ (12 )( 32.2 )
⎝ 64 ⎠
2
3 ⎛ πD ⎞
5(L) ⎜
⎟ ( L )( 0.28 )
⎝ 4 ⎠
(
3
60 ωcr
2π
ωcr = critical speed, rad/s
D = shaft diameter, inches
I = rectangular moment of inertia, in.4
Where, W = total weight, lb
Ncr = critical speed, rpm
L = effective length, inches
6
E = modulus of elasticity, psi, = 30 x 10 psi (for steel)
g = acceleration due to gravity = 32.2 fps2
Substituting the values of E and γ to ωcr: ωcr =
and N cr =
2
)
15”
MACHINE DESIGN/SHOP PRACTICE
⎛D⎞
ωcr = 446 000 ⎜ 2 ⎟
⎝L ⎠
•
or
⎛D⎞
N cr = 4 270 000 ⎜ 2 ⎟
⎝L ⎠
Note:
This is the lowest critical speed. Other critical speed can be found by multiplying the above equation by 4, 9, 16, 25, and so on.
c)
For the Disc Mounted Midway Between Bearings with the Shaft Weight Negligible: ωcr =
d)
For the Disc Mounted Any Point Between Bearings with the Shaft Weight Negligible: ωcr =
Where, a = distance of W from the left bearing, inches
576 E I g
W L3
36 E I g
a 2 b2 W
b = distance of W from the right bearing, inches
17. A power screw is rotated at constant angular speed of 90 rpm by applying a steady torque of 15 N-m. How much work is done per revolution?
a) 2.4 N-m/rev
b) 94.25 N-m/rev
c) 15 N-m/rev
d) 6.28 N-m/rev
Solution:
⎛ 2π rad ⎞
W
⎟⎟ = 94.25 N ⋅ m / rev
= T ⋅ θ = (15 N ⋅ m )⎜⎜
Re v
⎝ 1 revolution ⎠
3
18. A steel weighing 480 lb/ft has an ultimate strength of 80 000 psi. What is the maximum length of steel rod that could be hung vertically from its upper
end without rupturing?
a) 2 000 ft
b) 18 000 ft
c) 24 000 ft
d) 166.67 ft
⎛π⎞
⎛π⎞
W = 480 V = 480 ⎜ ⎟ D 2 L = s u ⎜ ⎟ D 2
⎝4⎠
⎝4⎠
su
80 000 (144)
=
= 24 000 ft
Then, Rod Length, L =
480
480
Solution: Weight of the steel rod,
6
19. A helical spring having squared and ground ends has a total of 18 coils and its material has a modulus of elasticity in shear of 11.5 x 10 psi. If the
spring has an outside diameter of 4 inches and a wire diameter of 0.25 inch, calculate the maximum deflection that can be produced in the spring due
to a load of 110 lb.
a) 16.53 inches
b) 15.63 inches
c) 13.56 inches
d) 15.36 inches
Solution:
D m = D o − d = 4 − 0.25 = 3.75 inches
No. of Active Coils,
C=
N a = N T − 2 = 18 − 2 = 16 coils
δ=
D m 3.75
=
= 15
d
0.25
8FC 3 N a
8(110)(15)3 (16 )
=
= 16.53 inches
Gd
11.5 x 10 6 (0.25)
(
)
o
20. Calculate the tooth thickness of 14½ full-depth involute spur gear with diametral pitch of 4.
a) 0.2937 inch
b) 0.3927 inch
c) 0.3297 inch
Solution:
Tooth thickness =
d) 0.7239 inch
1.5708 1.5708
=
= 0.3927 inch
Pd
4
o
21. A band brake is to absorb 3.75 kW at 250 rpm. The maximum pressure of the lining and the drum is 830 kPa. The angle of wrap is 206 , the width of
the band is 7.75 cm and the f = 0.15. If the diameter of the drum is 20 cm, determine the force on the tight side of the band.
a) 221.72 N
b) 121.27 N
c) 112.27 N
d) 127.12 N
Solution:
p max =
F1
wRθ
(
)
⎛ π ⎞
F1 = p max wRθ = (830)(0.0775)(0.10 ) 206 o ⎜
⎟ = 0.1123 kN = 112.27 N
⎝ 180 o ⎠
22. A solid circular shaft transmits 1500 kW at 300 rpm. For the material of shaft, permissible τ = 65 MPa, G=85GPa. Find the diameter of the shaft if angle
of twist does not exceed 1° per 20 diameter length.
A. 187 mm
B. 177 mm
C. 197 mm
D. 167 mm
Solution:
T=
30P 30 × 1500
=
= 47.75 kN.m ,
πN
π × 300
TL
,
θ=
JG
θ
32T
=
20D π × D 4 × G
∴
π
6
180 = 32 × 47.75 × 10
20 × D
π × D 4 × 85 × 103
1o ×
(
(
)
)
D = 187 mm
23. Find the stress induced in the cross section of a steel bar of 50 mm diameters subjected to an axial tensile force of 100 kN. What factor of safety if Sy is
300 MPa.
A. 4.5
B. 5.3
C. 5.9
D. 4.8
4
MACHINE DESIGN/SHOP PRACTICE
Sd =
Solution:
F 100 × 103
= 50.93 MPa
=
π 2
A
50
4
F.S =
( )
Sy
Sd
=
300
= 5. 9
50.93
24. Find the force required to punch a hole of 20 mm in a 15 mm thick plate of 30C8steel with ultimate shear strength of 275 MPa.
A. 386 kN
B. 259 kN
C. 273 kN
D. 325 kN
τ=
Solution:
F
F
,
=
A π× D× t
∴ F=
τ × π × D × t 275 × π × 20 × 15
=
= 259.181 kN ≅ 259 kN
1000
1000
25. What is the length of time in turning a 6” long workpiece at 600 rpm if the feed is 0.02 in. per revolution?
a) 0.4 min
b) 0.6 min
c) 0.3 min
d) 0.5 min
Solution: T = L =
fN
6in.
= 0.5 min .
in
.
rev ⎤
⎡
⎤⎡
0
.
02
600
⎢
rev ⎥⎦ ⎢⎣
min ⎥⎦
⎣
26. Determine the pitch required for a double-threaded square-form screw having a mean diameter of 3 inches and an efficiency of 50 %. Consider a
coefficient of friction equal to 0.15.
a) 0.5 inch
b) 0.75 inch
c) 0.625 inch
d) 0.25 inch
Solution: e =
tan λ
,
tan( β + λ )
0 .5 =
tan (β + λ ) =
where tan β = f = 0 .15 , then β = 8 .53 o
tan λ
,
tan( 8 .53 o + λ )
p=
tan λ =
then λ = 8 .944 o
π D m tan λ π (3) tan 8.944 o
=
= 0.741 inch
2
2
27. Determine the clearance of a spur gear with 25 teeth and a pitch of 4.
a) 0.9976 mm
b) 0.7699 mm
c) 0.9769 mm
Solution:
Clearance =
tan β + tan λ
1 − tan β tan λ
2p
Lead
=
π Dm π Dm
Use p = 0.75 inch
d) 0.0.6997 mm
0.1571 0.1571
=
= 0.0393 inch = 0.9976 mm
pd
4
28. A 50 lb motor should be automatically stopped by a brake when power is cut off. The motor must be brought to rest within 40 seconds after power is cut
2
off. The load inertia including the brake rotating member will be about 200 lb-ft . How many revolutions will the shaft turn before stopping if the shaft
turns at 1800 rpm?
a) 400 revolutions
b) 200 revolutions
c) 800 revolutions
d) 600 revolutions
Solution: ω = ω + αt
1
0
⎛ 40 ⎞
0 = 1800 + α⎜ ⎟
⎝ 60 ⎠
α = − 2700
rev
min 2
θ=
ω12 − ω o2 0 − (1800)2
=
= 600 revolutions
2α
2 (− 2700)
29. How long will it take to mill a 2-in. long keyway with a 24-tooth cutter turning at 130 rpm if the feed is 0.005 inch per tooth?
a) 0.128 min
b) 0.256 min
c) 0.324 min
d) 0.425 min
Solution:
t=
L
2in
=
= 0.128 min utes
f ( N)(n ) 0.005 in (24 teeth )(130 rev )
min
rev
tooth
30. A power screw is rotated at constant angular speed of 90 rpm by applying a steady torque of 15 N-m. How much work is done per revolution?
a) 2.4 N-m/rev
b) 94.25 N-m/rev
c) 15 N-m/rev
d) 6.28 N-m/rev
Solution:
⎛ 2π rad ⎞
W
⎟⎟ = 94.25 N ⋅ m / rev
= T ⋅ θ = (15 N ⋅ m )⎜⎜
Re v
⎝ 1 revolution ⎠
31. The flywheel of an engine has a mass of 2000 kg and radius of gyration equal to 1 m. The average torque on the flywheel is 1200 N-m. Determine the
angular acceleration of the flywheel.
2
2
2
2
b) 60 rad/s
c) 36 rad/s
d) 6 rad/s
a) 0.60 rad/s
Solution: Mass Moment of Inertia, I m = mk = (2000 kg )(1 m ) = 2000 kg ⋅ m
2
2
Torque of the Flywheel, T = I m α
α=
2
T 1200 kg ⋅ m / s 2 ⋅ m
=
= 0.60 rad / s 2
Im
2000 kg ⋅ m 2
5
MACHINE DESIGN/SHOP PRACTICE
32. A link of rectangular cross section is subjected to a pull of 40 kN. 30C8 steel with Sy = 330 MPa and Suc = 500 MPa is used. Find the cross section of
the link using a factor of safety of 4 and ratio of width to thickness of the section 2 : 0.
A. t=16 mm, W=32 mm
B. t=14 mm, W=28 mm
C. t=20 mm, W=40 mm
D. t=13 mm, W=26 mm
Solution:
Sy
Sd =
F.S
330
= 82.5MPa
4
=
Sd =
F
F
=
,
wt (2 t ) × t
t = 15.57 ≈ 16 mm
82.5 =
40 × 103
2 × t2
w = 2t = 2 (16) = 32 mm
33. A 100 mm diameter shaft subjected to a transverse load of 30 kN is supported in a bearing with permissible bearing pressure of 1.5 MPa. Find the
required length of the bearing.
A. 150 mm
B. 200 mm
C. 250 mm
D. 300 mm
Solution:
Sd =
F
F
,
=
A D×L
∴ 1.5 =
30 × 103
100 × L
L = 200 mm
34. A cylindrical shaft of outer diameter double the inner diameter is subjected to a bending moment of 15000 N.m and torque of 25000 N.m. Based on
MNST, find the outside and inside diameter of the shaft with F.S of 2 and the material be 30C8 with Sy=350MPa
B. do=112 mm, di=56 mm
C. do=90 mm, di=45 mm
D. do=98 mm, di=49 mm
A. do=100 mm, di=50 mm
Solution:
Sy
Sd =
F.S
350
= 175 MPa
2
=
⎡ 32d
Sd = ⎢ 4 o 4
⎢⎣ π d o − di
(
⎤
⎥
⎥⎦
)
⎛
2
2
⎜M+ M +T
⎜⎜
2
⎝
(
⎞ ⎧
⎟ ⎪ 32(2d i )
⎟⎟ = ⎨
⎪ π (2d i )4 − d i4
⎠ ⎩
[
]
⎛
2
2
⎜M+ M +T
⎜⎜
2
⎝
) (15000 ×10 ) + (25000 ×10 )
⎡
3
⎢ 15000 × 10 +
3⎢
π × 15 × d i ⎢
⎣
64
175 =
⎫⎪
⎬
⎪⎭
3 2
3 2
2
di = 55.54 ≅ 56 mm
⎞ ⎡
64
⎟
⎟⎟ = ⎢ π 15d 3
i
⎠ ⎢⎣
⎤
⎥
⎥⎦
( )
⎛
2
2
⎜M+ M +T
⎜⎜
2
⎝
⎞
⎟
⎟⎟
⎠
⎤
⎥
⎥
⎥
⎦
d o = 2 d i = 2 × 56 = 112 mm
35. A thin walled cylinder with mean diameter 150 mm is subjected to a twisting moment of 1.5 kN. And an internal pressure of 2.5 MPa. If the material
used is 30C8 steel with Sy=320 MPa and F.S = 2.5, find the wall thickness using maximum shear stress theory.
A. 1.5 mm
B.
C.
D.
Solution:
PDi
,
2t
St =
∴ t=
PDi 2.5 × 150
=
= 1.46 ≅ 1.5 mm
320
2St
2×
2.5
5
36. Determine the diameter of a ductile steel bar subjected to an axial tensile load of 40 kN and a torsional moment of 16 x 10 N.mm. Use factor of safety
5
of 1.5, E=2 x 10 MPa and Sy=210 MPa.
A. 69 mm
B. 59mm
C. 49 mm
D. 39 mm
Solution:
(
)
F
40 × 103 × 4 5.0929 × 104
MPa
=
=
A
D2
π × D2
St =
Ss =
16 × T
π × D3
=
(
16 × 16 × 105
π × D3
) = 81.487 ×10
D3
5
MPa
Applying maximum shear stress theory,
Sd =
Sy
F.S
Sy
F.S
2
=
16
π × D3
M2 + T2 =
16
π × D3
2
⎛ St × π × D3 ⎞ ⎛ Ss × π × D3 ⎞
⎜
⎟ +⎜
⎟ = 16
⎜
⎟
⎜
⎟
32
16
π × D3
⎝
⎠ ⎝
⎠
2
=
S2t
5⎞
⎛ 5.0929 × 104 ⎞
⎛
210
⎟ + 4⎜ 81.487 × 10 ⎟
∴
= ⎜
⎜
⎟
⎜
⎟
1.5
D2
D3
⎝
⎠
⎝
⎠
+ 4Ss2 ,
⎛ π2 × D6 ⎞
⎜
⎟
⎜ 162 ⎟
⎝
⎠
⎛ S2t
⎞
⎜
+ Ss2 ⎟
⎜ 4
⎟
⎝
⎠
2
by trial and error, D = 49 mm
37. A 20 mm shaft is subjected to an axial load of 40 kN and is designed based on maximum energy of distortion as the criteria of failure and factor of
safety of 2. If the material used is 30C8 steel with Sy=310 MPa, determine the maximum torque that can be applied to the shaft before yielding.
A. 70.81 N.m
B. 71. 80 N.m
C. 81.07 N.m
D. 80.17 N.m
Solution:
St =
F 32M
=
,
A πD3
Sd =
Sy
F.S
=
32
πD
3
∴
M2 +
3 2
T
4
40 × 103 32 × M
=
π 2
π × 203
20
4
M = 100 × 103 N.mm
( )
∴
310
32
=
2
π × (20)3
6
(100 ×10 ) + 34 T
3 2
2
,
T = 80.17 N.mm
MACHINE DESIGN/SHOP PRACTICE
38. A shaft is subjected to a twisting moment of 5 kN.m and a bending moment of 2 kN.m. If the material has Sy=330 MPa and F.S=4, find the diameter of
the shaft using maximum shear stress theory.
A. 39. 6 mm
B. 96.3 mm
C. 36.9 mm
D. 69.3 mm
Solution:
Shafts under combined torsion and bending loads (MSST)
Sd =
Sy
F.S
=
16
πD
3
M2 + T2 ,
∴
(
330 ⎛ 16 ⎞
= ⎜⎜
⎟ 2 × 106
3⎟
4
⎝ π× D ⎠
) + (5 ×10 )
2
6 2
D = 69.3 mm
39. The flywheel of an engine has a mass of 2000 kg and radius of gyration equal to 1 m. If the average torque on the flywheel is 1200 N-m, what is its
angular speed after 10 seconds starting from rest?
a) 60 rad/s
b) 6 rad/s
c) 0.60 rad/s
d) 36 rad/s
Solution: Mass Moment of Inertia, I = mk = (2000 kg )(1 m ) = 2000 kg ⋅ m
2
2
Torque of the Flywheel, T = I α
2
T 1200 kg ⋅ m / s 2 ⋅ m
=
= 0.60 rad / s 2
I
2000 kg ⋅ m 2
α=
ωf = ωo + αt = 0 + 0.60(10 ) = 6 rad / s
40. A disc clutch has 6 pairs of contacting friction surfaces with an outside diameter of 200 mm and an inside diameter of 100 mm. The coefficient of friction
of the clutch materials is 0.4 and the axial force is 1500 N. The shaft speed is 1200 rpm. Determine the Hp that can be transmitted by the clutch
assuming uniform pressure.
a) 35.2 Hp
b) 23.5 Hp
c) 47.2 Hp
d) 27.4 Hp
Solution: Friction Radius (Uniform pressure), rf =
3
3
2 ⎛⎜ ro − ri
3 ⎜ ro2 − ri2
⎝
⎞ ⎛ 2 ⎞ ⎡ (100)3 − (50)3 ⎤
⎟ = ⎜ ⎟⎢
= 77.78 mm
⎟ ⎝ 3 ⎠ ⎢ (100)2 − (50)2 ⎥⎥
⎣
⎦
⎠
Friction Power or Transmitted Power or Power Capacity, P =
π n Tf
πn
=
(Ff rf n f ) = π n (f Fa rf n f ) = π(1200) (0.4)(1.5)(0.07778)(6)
30
30
30
30
P = 35.19 kW = 47.2 Hp
Where,
P = power capacity, kW
Ff = friction force, kN
Rf = friction radius or mean radius, m
Tf = torque capacity, kN-m
Fa = axial load, kN
nf = no. of pairs of contacting friction surfaces
41. A flywheel has a mean diameter of 4 ft and is required to handle 2250 ft-lb of kinetic energy. It has a width of 8 inches, mean operating speed is 300
rpm and the coefficient of fluctuation is to be 0.05. Find the weight of rim, in kg, assuming that the arms and hub are equivalent to 10 % of the total rim
weight. The flywheel is made up of cast iron with specific weight of 0.26 lb per cubic inch.
a) 151.34 kg
b) 115.34 kg
c) 135.14 kg
d) 145.13 kg
Solution: ∆KE =
Where,
1.10 W
Cf V 2
g
V = mean velocity =
W=
g (∆KE )
1.10 Cf V 2
=
32.2(2250)
1.10(0.05)(62.83)2
πDn π(4 )(300)
=
= 62.83 fps
60
60
g = acceleration due to gravity = 32.2 fps
= 333.7 lb
Cf = coefficient of fluctuation
2
∆KE = Kinetic Energy
42. If two parallel shafts are connected by cylinders in pure rolling contact and turning in opposite directions, and having a speed ratio of 2.75, what is the
Center distance of the two shafts assuming that the diameter of the smaller cylinder is 22 cm?
a) 41.25 cm
b) 19.25 cm
c) 20.25 cm
d) 40.25 cm
Solution: Diameter of the bigger cylinder, D 2 = SR (D 1 ) = 2.75(22 ) = 60.5 cm
Center distance,
C=
D 2 − D1 60.5 + 22
=
= 41.25 cm
2
2
43. Determine the power lost when a collar is loaded with 1 metric ton, rotates at 50 rpm, and has a coefficient of friction of 0.15. The outside
diameter of the collar is 10.16 cm and the inside diameter is 5.08 cm.
a) 304.23 W
b) 0.30423 W
c) 304.23 kW
d) 0.30423 Hp
Solution:
Where,
Tf π n f W rf π n 0.15(1000 kg )(9.8066 N / kg )(0.0395)(50 rpm )(π)
=
=
= 304.23 W
30
30
30
3
3
2 ⎛ r − r ⎞ 2 ⎡ (5.08)3 − (2.54 )3 ⎤
rf = ⎜ o2 i2 ⎟ = ⎢
⎥ = 3.95 cm
3 ⎜⎝ ro − ri ⎟⎠ 3 ⎣⎢ (5.08)2 − (2.54 )2 ⎦⎥
fHp =
7
MACHINE DESIGN/SHOP PRACTICE
44. A 30 mm diameter steel shaft is subjected to maximum bending moment of 100 N.m; an axial tensile force of 5000 N and a torque of 200 N.m. If
Sy=240 MPa, determine the factor of safety using maximum shear stress theory.
A. 7.45
B. 4.75
C. 7.54
D. 5.47
Solution:
Shafts under combined torsion, bending and axial loads (MSST)
Sd =
Sy
F.S
=
16
πD3
DP ⎞
⎛
T2 + ⎜ M +
⎟
8 ⎠
⎝
2
∴
(
) (
)
2 ⎡
240 ⎛ 16 ⎞
30 × 5000 ⎤
=⎜
⎟ 200 × 103 + ⎢ 100 × 103 +
⎥
F.S ⎜⎝ π × 303 ⎟⎠
8
⎣
⎦
2
F.S = 5.47
5
45. Determine the diameter of a ductile steel bar to an axial tensile load of 40000 N and a torsional moment of 16 x 10 N.mm. Use Maximum shear stress
5
theory, factor of safety of 5, E=2.1 x 10 MPa, Sy=210 MPa.
A. 58.2 mm
B. 28.5 mm
C. 82.5 m
D. 52.8 mm
Solution:
Shafts under combined torsion and axial loads (MSST)
Sd =
Sy
F.S
=
16
πD3
⎛ DP ⎞
T2 + ⎜
⎟
⎝ 8 ⎠
2
∴
(
)
2 ⎛ D × 40000 ⎞
210 ⎛ 16 ⎞
= ⎜⎜
⎟⎟ 16 × 105 + ⎜
⎟
3
5
8
⎠
⎝
⎝ π× D ⎠
2
D = 58.2 mm
46. A 500 mm diameter thin walled cylindrical shell, having Sy=300 MPa and factor of safety of 4, is subjected to an axial tension of 300 kN and a torque of
40 kN.m. Find the wall thickness using maximum shear stress theory.
A. 5.2 mm
B. 50.2 mm
C. 2.5 mm
D. 20.5 mm
Solution:
S=
Sy
F.S
=
F
F
=
A πDt
∴ t=
(
)
F × F.S
300 × 103 × 4
=
= 2.5
Sy × π × D 300 × π × 500
o
47. A helical gear of 10 inches pitch diameter has a helix angle of 30 , and there are 30 teeth. Find the value of the normal circular pitch.
a) 0.9069 inch/tooth
b) 0.6909 inch/tooth
c) 0.6096 inch/tooth
d) 0.9906 inch/tooth
Solution:
Pc =
πD π (10 )
=
= 1.0472 inches / tooth
T
30
(
)
Pcn = Pc cos ψ = 1.0472 cos 30o = 0.9069 inch / tooth
o
o
48. A parallel helical gear set was a 17-tooth pinion driving a 34-tooth gear. The pinion has a right-hand helix angle of 30 , a normal pressure angle of 20 ,
and a normal diametral pitch of 5 teeth/in. Find the axial circular pitches.
a) 1.2566 inches/tooth
b) 1.6625 inches/tooth
c) 1.6526 inches/tooth
d) 1.6256 inches/tooth
Solution:
Pc =
Pcn
0.62832
=
= 0.72552 inch / tooth
cos ψ cos 30o
Pa =
49. It is a typical of material used for cylinder block.
a) Forged steel
c) Cast iron and coated with chrome or molybdenum
50. Which of the following is a material used for a piston ring?
a) Forged steel
c) Cast iron and coated with chrome or molybdenum
Pc
0.72552
=
= 1.2566 inches / tooth
tan ψ tan 30o
b) Drop-forged, heat-treated steel\
d) Cast iron
b) Drop-forged, heat-treated steel\
d) Cast iron
51. Which of the following is the typical material used for an engine crank shaft?
a) Forged steel
b) Heat-treated steel
c) Cast iron
d) Wrought iron
52. In flange coupling, which of the following is the weakest element?
a) Flange
b) Shaft
c) Bolt brush
d) Key
53. What is the function of a governor?
a) Store energy and give up whatever needed
b) Regulate the speed during one cycle of a prime mover
c) Increase variation of speed
d) Adjust variation of speed by varying the input to the engine
54. A cam with a roller follower would constitute which type of pair?
a) Lower pair
b) Open pair
c) Higher pair
d) Closed pair
55. It is defined as that profession in which knowledge of the mathematical and natural sciences gained by study, experience, and practice is applied with
judgment to develop ways to utilize, economically, the materials and forces of nature for the benefit of mankind.
a) Physics
b) Engineering
c) Accountancy
d) Chemistry
56. How do you call the transformation of concepts and ideas into useful machinery?
a) Invention
b) Modification
c) Innovation
d) Design
57. It is the peak of the stress-strain curve and sometimes simply called as tensile strength. How do you call this?
a) Yield strength
b) Ultimate tensile strength
c) Endurance strength
d) Elastic strength
58. It is a synergistic collection of machine elements. It is synergistic because as a design it represents an idea or concept greater than the sum of the
individual parts. How do you call this?
8
MACHINE DESIGN/SHOP PRACTICE
a) Synthesis
b) Analysis
c) Mechanical system
d) Concurrent engineering
59. How do you call the ratio of stress and strain?
a) Modulus of rigidity
b) Modulus of resilience
d) Modulus of elasticity
d) Modulus of stiffness
60. What is the philosophy of involving many disciplines from the beginning of a design effort and keeping them involved throughout product development?
a) Synthesis
b) Design
c) Mechanical system
d) Concurrent engineering
61. It is one of the design stages that may be found desirable to use field experience as a basis for further improvement of the product. Since the final
product is available, it often becomes the model for evaluation during this design process. This statge is not always used in the design process. How do
you call this?
a) Detail stage
b) Revision stage
c) Preliminary stage
d) Feasibility stage
62. That portion of the stress-strain diagram where there is a large increase in strain with little or no increase in stress is called as:
a) Yield strength
b) Ultimate tensile strength
c) Endurance strength
d) Elastic strength
63. This is the first stage of design processes that determines whether it is both possible and profitable to undertake a given engineering project. The ideas
generated during this stage of the design process generally consist of general statements about overall concepts rather than specific descriptions of
hardware. How do you call this?
a) Detail stage
b) Revision stage
c) Preliminary stage
d) Feasibility stage
64. That portion on the stress-strain curve where it deviates from the straight line is called which of the following?
a) Elastic limit
b) Proportional limit
c) Endurance limit
d) Yield point
65. At this point in the stress-strain curve, the material experiences some amount of plastic strain and thus will not return to its original shape after release
of the load.
a) Elastic limit
b) Proportional limit
c) Endurance limit
d) Yield point
66. In the Stress-strain diagram, what do you call the peak point on the stress-strain curve?
a) Yield point
b) Ultimate strength
c) Elastic limit
d) Proportional limit
67. This type of load is the one that is applied slowly and never removed. How do you call this load?
a) Static load
b) Fluctuating load
c) Random load
d) Fluctuating load
68. At the highest point of the stress-strain curve during the test, what highest stress on a test bar of the material is measured?
a) Apparent stress
b) Ultimate stress
c) Elastic stress
d) Yield stress
69. This is a stress when a given element of a load-carrying member is subjected to a certain level of tensile stress followed by the same level of
compressive stress; the stress cycle is repeated many thousands of times. How do you call this type of stress?
a) Repeated and Reversed Stress
b) Static stress
c) Minimum stress
d) Maximum stress
70. After peak of the curve in the stress-strain diagram is reached, there is a pronounced decrease in the bar’s diameter and that is referred to as:
a) Yielding down
b) Sloping down
c) Necking down
d) Deflection
71. This is a stress when a load-carrying member is subjected to an alternating stress with non-zero mean. How do you call this type of stress?
a) Repeated and Reversed Stress
b) Static stress
c) Fluctuating stress
d) Static stress
72. How do you call a stress that is computed by dividing the load by the original cross-sectional area of the test bar before straining occurs?
b) Apparent stress
c) Elastic stress
d) Yield stress
a) Ultimate stress
73. This is the ability of material to withstand fatigue loads. It is the stress level that a material can survive for a given number of cycles of loading.
a) Endurance strength
b) Yield strength
c) Ultimate strength
d) Elastic strength
74. This is that portion of the stress-strain diagram where there is a large increase in strain with little or no increase in stress. How do you call this portion?
a) Yield strength
b) Proportional limit
c) Elastic limit
d) Ultimate strength
75. How do you call the point on the stress-strain curve where it deviates from a straight line?
a) Elastic limit
b) Proportional limit
c) Yield point
d) Ultimate strength
76. It is a push or pull applied to a body that results in a change in the body's motion or in some deformation of the body.
a) Force
b) Work
c) Energy
d) Momentum
77. What is the ratio of shearing stress to shearing strain? This property indicates a material's stiffness under shear loading—that is, the resistance to shear
deformation.
a) Modulus of elasticity in shear b) Young’s Modulus of elasticity
d) Poisson’s Ratio
d) d) Unit deformation
78. This test uses a square specimen with a 2.0 mm (0.079 in) deep notch, but it is centered along the length. The specimen is placed against a rigid anvil
without being clamped. The notch faces away from the place where the striker contacts the specimen. The loading can be described as the bending of
a simply supported beam. This test is most often used for testing metals.
a) Charpy test
b) Izod test
c) Drop-weight tester
d) All of these
79. The transformation of concepts and ideas into useful machinery is called as:
a) Design
b) Synthesis
c) Analysis
80. It is the degree to which a material will deform before ultimate fracture. How do you call this?
a) Ductility
b) Brittleness
c) Toughness
d) Theorem
d) Stiffness
81. This impact test of material employs a square specimen with a V-shaped notch carefully machined 2.0 mm (0.079 in) deep according to specificafions
in ASTM .standard D 256. The specimen is clamped in a special vise with the notch aligned with the top edge of the vise. The striker contacts the
specimen at a height of 22 mm above the notch, loading it as a cantilever in bending. How do you call this test?
a) Charpy test
b) Izod test
c) Drop-weight tester
d) All of these
82. It is defined as synergistic collection of machine elements; synergistic because as a design it represents an idea or concept greater than the sum of the
individual parts.
a) System of mechanisms
b) Mechanical system
c) Design system
d) Expert system
83. It may be defined the displacement per length produced in a solid as the result of stress.
9
MACHINE DESIGN/SHOP PRACTICE
a) Deformation
b) Elongation
c) Strain
84. What is the measure of the change in length of a material subjected to a change in temperature?
a) Thermal conductivity
b) Coefficient of thermal expansion c) Strain
d) Stress
d) Coefficient of fluctuation
85. Which of the following is the opposite of ductility?
a) Brittleness
b) Toughness
c) Stiffness
d) Rigidity
86. This is possibly the most widely used material for machine elements because of its properties of high strength, high stiffness, durability, and relative
ease of fabrication. It refers to an alloy of iron, carbon, manganese, and one or more other significant elements.
a) Steel
b) Copper
c) Iron
d) Zinc
87. When a material is subjected to a tensile strain, there is a simultaneous shortening of the cross-sectional dimensions perpendicular to the direction of
the tensile strain. The ratio of the shortening strain to the tensile strain is called as:
a) Poisson’s Ratio
b) Young’s modulus of elasticity
c) Strain
d) Unit deformation
88. It is the ratio of shearing stress to shearing strain. This property indicates a material's stiffness under shear loading—that is, the resistance to shear
deformation. How do you call this?
a) Modulus of elasticity in shear b) Young’s modulus of elasticity
c) Modulus elasticity
d) Modulus of resilience
89. These steels contain 30 to 50 points of carbon (0.30%-0.50%). Most machine elements having moderate to high strength requirements with fairly good
ductility and moderate hardness requirements come from this group.
a) High-carbon steels
b) Medium-carbon steels
c) Low-carbon steels
d) Alloy steels
90. This is another stiffness measure often reported, particularly for plastics. As the name implies, a specimen of the material is loaded as a beam in flexure
(bending) with data taken and plotted for load versus deflection. From these data and from knowledge of the geometry of the specimen, stress and
strain can be computed. The is also the ratio of stress to strain. How do you call this?
a) Flexural modulus
b) Young’s modulus of elasticity
c) Modulus elasticity
d) Modulus of resilience
91. How do you call the resistance of a material to indentation by a penetrator?
a) Machinability
b) Hardness
c) Brittleness
d) Toughness
92. The combination of applied normal and shear stresses that produces maximum principal normal stress or minimum principal normal stress, with a third
principal stress between or equivalent to the extremes.
a) Principal shear stress
b) Principal normal stress
c) Maximum shear stress
d) Bending and shear stresses
93. These steels have 50 to 95 points of carbon (0.50%-0.95%). These provide better wear properties suitable for applications requiring durable cutting
edges and for applications where surfaces are subjected to constant abrasion. Tools, knives, chisels, and many agricultural implement components are
among these uses.
a) High-carbon steels
b) Medium-carbon steels
c) Low-carbon steels
d) Alloy steels
94. It is related to the ease with which a material can be machined to a good surface finish with reasonable tool life. It is difficult to define measurable
properties related to this, it is usually reported in comparative terms, relating the performance of a given material with some standard.
a) Machinability
b) Hardness
c) Brittleness
d) Toughness
95. This improves the toughness, hardenability, and corrosion resistance of steel and is included in most of the alloy steels. How do you call this material?
a) Nickel
b) Chromium
c) Vanadium
d) Sulfur
96. It is a load applied transversely to longitudinal axis of member.
a) Combined loads
b) Concentrated load
c) Bending load
d) Distributed load
97. This material improves the hardenability, wear and abrasion resistance, and strength at elevated temperatures. In high concentrations, it provides
significant corrosion resistance, as of stainless steels.
a) Nickel
b) Chromium
c) Vanadium
d) Sulfur
98. What is the ability of a material to absorb applied energy without failure?
a) Toughness
b) Hardness
c) Stiffness
d) Brittleness
99. It is the intensity and direction of internal force acting at given point on particular plane.
a) Load
b) Strain
c) Stress
d) Sustained load
100. It is the capacity of a material to absorb energy when it is deformed elastically and then, upon unloading, to increase this energy.
a) Resilience
b) Toughness
c) Rigidity
d) Ductility
101. It is the strain energy per unit volume required to stress a material from an unloaded state to the point of yielding.
a) Modulus of roughness
b) Modulus of elasticity
c) Modulus of rigidity
d) Modulus of resilience
102. This group of materials characterizes the high level of corrosion resistance offered by alloys in this group. To be classified on this group of material, the
alloy must have a chromium con tent of at least 10%, and most have 12% to 18% chromium.
a) Stainless steels
b) Structural steels
c) Tool steels
d) Mild steels
103. The ability of the material to absorb energy up to fracture.
a) Toughness
b) Rigidity
c) Resilience
d) Stiffness
104. These group of stainless steels fall into the AISI 200 and 300 series. They are general-purpose grades with moderate strength. Most are not heattreatable, and their final properties are determined by the amount of working, with the resulting temper referred to as 1/4 hard, ½ hard, 3/4 hard, and full
hard. These alloys are nonmagnetic and are typically used in food processing equipment.
a) Austenitic stainless steels
b) Ferritic stainless steels
c) Martensitic stainless steels
d) None of these
105. These stainless steels belong to the AISI 400 series, designated as 405, 409, 430, 446, and so on. They are magnetic and perform well at elevated
temperatures, from 1300°F to 1900°F (700°C-1040°C), depending on the alloy. They are not heat-treatable, but they can be cold-worked to improve
properties. Typical applications include heat exchanger tubing, petroleum refining equipment, automotive trim, furnace parts, and chemical equipment.
a) Austenitic stainless steels
b) Ferritic stainless steels
c) Martensitic stainless steels
d) None of these
10
MACHINE DESIGN/SHOP PRACTICE
the following items are for your reading and familiarization
106. These stainless steels are also members of the AISI 400 series, including 403, 410, 414, 416, 420, 431, and 440 types. They are magnetic, can be
heat-treated, and have higher strength than the 200 and 300 series, while retaining good toughness. Typical uses include turbine engine parts, cutlery,
.scissors, pump parts, valve parts, surgical instruments, aircraft fittings, and marine hardware.
a) Austenitic stainless steels
b) Ferritic stainless steels
c) Martensitic stainless steels
d) None of these
107. A theory in cyclic and impact loading, which states that damage at any stress level is proportional to number of cycles.
a) Miner’s Rule
b) Paris Power Law
c) Goodman Rule
d) Manson-Coffin Relationship
108. The property of a material that measures the degree of plastic deformation sustained at fracture.
a) Toughness
b) Stiffness
c) Ductility
d) Brittleness
109. Most of these materials are designated by ASTM numbers established by the American Society for Tesfing and Materials. One common grade is ASTM
A36, which has a minimum yield point of 36 000 psi (248 MPa) and is very ductile. It is basically a low-carbon, hot-rolled steel available in sheet, plate,
bar, and structural shapes such as some wide-flange beams, American Standard beams, channels, and angles.
a) Structural steels
b) Tool steels
c) Cast steels
d) Stainless steels
110. Compounds of metallic elements, most frequently oxides, nitrides, and carbides.
a) Plastic
b) Polymers
c) Ceramics
d) Alloy
111. This material refers to a group of steels typically used for cutting tools, punches, dies, shearing blades, chisels, and similar uses. The numerous
varieties of tool steel materials have been classified into seven general types. Whereas most uses of these steels are related to the field of
manufacturing engineering, they are also pertinent to machine design where the ability to maintain a keen edge under abrasive conditions is required.
Also, some of these steels have rather high shock resistance which may be desirable in machine components such as parts for mechanical clutches,
pawls, blades, guides for moving materials, and clamps.
a) Structural steels
b) Tool steels
c) Cast steels
d) Stainless steels
112. A material having different properties in all directions at point in solid.
a) Isotropic material
b) Anisotropic material
c) Orthotropic material
d) Ceramic material
113. Parts subjected to repeated applications of loads or to stress conditions that vary with time over several thousands or millions of cycles fail because of
the phenomenon of fatigue. Materials are tested under controlled cyclic loading to determine their ability to resist such repeated loads. The resulting
data are reported as which of the following?
a) Endurance strength
b) Ultimate strength
c) Yield strength
d) Elastic strength
114. Which of the following is the other term for endurance strength?
a) Fatigue strength
b) Ultimate strength
c) Yield strength
d) Elastic strength
115. A material having different properties in three mutually perpendicular directions at point in solid and having three mutually perpendicular planes of
material symmetry.
a) Orthotropic material
b) Isotropic material
c) Anisotropic material
d) Thermoplastic material
116. The combinations of two or more materials, usually consisting of fiber and thermosetting polymer.
a) Brittle materials
b) Composite materials
c) Polymers
d) Ceramics
117. It is a load that is applied slowly and is never removed. How do you call this?
a) Fluctuating load
b) Static load
c) Combined loads
d) Cyclic load
118. These are loads that vary during the normal service of the product. These loads are typically applied for quite a long time so the part experiences many
thousand or millions of cycles of stress during its expected life. How do you call these loads?
a) Cyclic loads
b) Repeated loads
c) Fluctuating loads
d) Static loads
119. This is the resulting stress when a part is subjected to a load that is applied slowly, without shock, and is held at a constant value. What is this stress?
a) Static stress
b) Repeated stress
c) Fatigue stress
d) Fluctuating stress
120. When materials are subjected to high loads continuously, they may experience progressive elongation over time. This phenomenon should be
considered for metals operating at high temperatures. It is important for critical members in internal combustion engines, furnaces, steam turbines, gas
turbines, nuclear reactors, or rocket engines. How do you call this phenomenon?
a) Relaxation
b) Thermal conductivity
c) Resilience
d) Creep
121. This is the stress when a load-carrying member is subjected to an alternating stress with a non-zero mean. How do you call this stress?
a) Fluctuating stress
b) Repeated stress
c) Fatigue stress
d) Static stress
122. Large gears, machine structures, brackets, linkage parts, and other important machine parts are made from this material. The several types of grades
available span wide ranges of strength, ductility, machinability, wear resistance, and cost. These features are attractive in many applications. How do
you call this material?
a) Structural steel
b) Tool steel
c) Cast steel
d) Stainless steel
123. A stress reversal occurs when a given element of a load-carrying member is subjected to a certain level of tensile stress followed by the same level of
compressive stress. If this stress cycle is repeated many thousands of times, the stress is call what?
a) Fatigue stress
b) Repeated and reversed stress
c) Static stress
d) Fluctuating stress
124. It is a loading when varying loads are applied that are not regular in their amplitude. How do you call this loading?
a) Random loading
b) Shock loading
c) Impact load
d) Static loading
125. It is the ability of a material to withstand fatigue loads. It is the stress level that a material can survive for a given number of cycles of loading. What is
this?
a) Endurance strength
b) Fatigue strength
c) yield strength
d) Ultimate strength
126. This material is available in grades having tensile strengths ranging from 20 000 to 60 000 psi (138 - 414 MPa). Its ultimate compressive strength is
much higher, three to five times as high as the tensile strength. One disadvantage of material is that it is brittle and therefore should not be used in
applications where impact loading is likely. But it has excellent wear resistance, is relatively easy to machine, has good vibration damping ability, and
can be surface-hardened. Applications include engine blocks, gears, brake parts, and machine bases.
a) Gray iron
b) Malleable iron
c) Ductile iron
d) Austempered ductile iron
127. In the Stress-strain diagram, what do you call the peak point on the stress-strain curve?
11
MACHINE DESIGN/SHOP PRACTICE
a) Yield point
b) Ultimate strength
c) Elastic limit
d) Proportional limit
128. This is a group of heat-treatable cast irons with moderate to high strength, high modulus of elasticity (stiffness), good machinability. and good wear
resistance. The five-digit designation roughly indicates the yield strength and the expected percent elongation of the iron. For example, Grade 40010
has a yield strength of 40 ksi (276 MPa) and a 10% elongation.
a) Gray iron
b) Malleable iron
c) Ductile iron
d) Austempered ductile iron
129. It is the degree to which a material will deform before ultimate fracture. How do you call this?
a) Ductility
b) Brittleness
c) Toughness
d) Stiffness
130. These cast irons have higher strengths than the gray irons and, as the name implies, are more ductile. However, their ductility is still much lower than
that of typical steels. A three-part grade designation is used for ductile iron in the ASTM A536-84 specification. The first number refers to the tensile
strength in ksi, the second is the yield strength in ksi, and the third is the approximate percent elongation. For example, the grade 80-55-06 has a
tensile strength of 80 ksi (552 MPa). a yield strength of 55 ksi (379 MPa), and a 6% elongation in 2.00 in. Higher-strength cast parts, such as
crankshafts and gears, are made from this iron.
a) Gray iron
b) Malleable iron
c) Ductile iron
d) Austempered ductile iron
131. When a material is subjected to a tensile stain, there is a simultaneous shortening of the cross-sectional dimensions perpendicular to the direction of
tensile strain. The ratio of the shortening strain to the tensile strain is called as:
a) Modulus of elasticity
b) Young’s Modulus
c) Poisson’s Ratio
d) Modulus of Rigidity
132. How do you call a stress that is computed by dividing the load by the original cross-sectional area of the test bar?
a) Ultimate stress
b) Apparent stress
c) Elastic stress
d) Yield stress
133. This is that portion of the stress-strain diagram where there is a large increase in strain with little or no increase in stress. How do you call this portion?
a) Yield strength
b) Proportional limit
c) Elastic limit
d) Ultimate strength
134. This material is widely used for structural and mechanical applications. Chief among its attractive properties are light weight, good corrosion resistance,
relative ease of forming and machining, and pleasing appearance. Its density is approximately one-third that of steel. However, its strength is somewhat
lower, also.
a) Aluminum
b) Steel
c) Zinc
d) Brass
135. It is an attempt to duplicate how the human mind works in computer processes. How do you call this?
a) Computed Aided Design
b) Artificial intelligence
c) Conceptual framework
d) Theoretical framework
136. What is a design approach wherein all disciplines involved with a product are in the development process from beginning to end?
a) Concurrent Engineering
b) Reversed Engineering
c) Re-engineering
d) Machine Design
137. What is a synergetic collection of machine elements?
a) Mechanical System
b) Measurement system
c) Control system
d) System Design
138. This is an additional capacity or incorporation of back up systems so that a component failure does not lead to catastrophic loss. How do you call this?
a) Redundancy
b) Prototyping
c) Machine Element Function
d) Drafting
139. How do you call a structural member designed to support loads perpendicular to its longitudinal axis?
a) Beam
b) Column
c) Shaft
d) Cantilever
140. What is a load applied transversely to longitudinal axis of member?
a) Bending load
b) Axial load
141. How do you call the ability of a material to withstand load without failure?
a) Strength
b) Stress
c) Torsional load
d) Simple load
c) Strain
d) Yield stress
142. It is the force or load applied to a material per unit area. What do you think it is?
b) Stress
c) Strain
d) Yield stress
a) Strength
143. It is related to the ease with which a material can be machined to a good surface finish with reasonable tool life. What is this?
a) Machinability
b) Toughness
c) Endurance strength
d) Hardness
144. How do you call the ability of a material to absorb applied energy without failure?
a) Machinability
b) Toughness
c) Endurance strength
d) Hardness
145. This material is widely used in its nearly pure form for electrical and plumbing applications because of its high electrical conductivity and good corrosion
resistance. It is rarely used for machine parts because of its relatively low strength compared with that of its alloys, brass and bronze.
a) Copper
b) Brass
c) Bronze
d) Aluminum
146. This material is a family of alloys of copper and zinc, with the content of zinc ranging from about 5% to 40%. Brass is often used in marine applications
because of its resistance to corrosion in salt water. This also has excellent machinability and used as connectors, fittings, and other parts made on
screw machines.
a) Copper
b) Brass
c) Bronze
d) Aluminum
147. It is a theory stating that failure is caused by elastic energy associated with shear deformation. How do you call this theory?
a) Distortion-energy theory
b) Maximum-shear stress theory
c) Internal friction theory
d) Modified Mohr theory
148. This brass material contains about 30% or more of zinc and often contains a significant amount of lead to improve machinability.
a) Yellow brass
b) Red brass
c) White brass
d) Blue brass
149. A sketch of a machine, a machine element, or part of a machine element that shows all acting forces, such as applied loads and gravity forces, and all
reactive forces.
a) Schematic diagram
b) Free body diagram
c) Moment diagram
d) Skeletal diagram
150. This brass contains 5% to 15% zinc. How do you call this?
a) Yellow brass
b) Red brass
c) White brass
d) Blue brass
151. It is the property of a material that indicates its ability to transfer heat. What is this?
a) Electric resistivity
b) Thermal conductivity
c) Thermal resistance
d) Cohesiveness
152. This is a class of alloys of copper with several different elements, one of which is usually tin. They are useful in gears, bearings, and other applications
where good strength and high wear resistance are desirable.
a) Copper
b) Brass
c) Bronze
d) Aluminum
153. A positive normal stress means:
a) Direct tensile stress
b) Compressive stress
c) Clockwise rotation
d) Counter clockwise rotation
154. A positive shear stress is one that:
a) Tends to rotate the stress element clockwise
b) Tends to rotate the stress element counterclockwise
c) Directs the vector towards the stress element
d) Directs the vector pointing away from stress element
155. Compounds of metallic elements, most frequently oxides, nitrides, and carbides.
a) Plastic
b) Polymers
c) Ceramics
d) Alloy
156. A material having different properties in all directions at point in solid.
12
MACHINE DESIGN/SHOP PRACTICE
a) Isotropic material
b) Anisotropic material
c) Orthotropic material
d) Ceramic material
157. A material having different properties in three mutually perpendicular directions at point in solid and having three mutually perpendicular planes of
material symmetry.
a) Orthotropic material
b) Isotropic material
) Anisotropic material
d) Thermoplastic material
158. It is possibly the most widely used material for machine elements because of its properties of high strength, high stiffness, durability, and relative ease
of fabrication. The term refers to an alloy of iron, carbon, manganese, and one or more other significant elements. How do you call this material?
a) Zinc
b) Aluminum
c) Steel
d) Iron
159. It is any process in which steel is subjected to elevated temperatures to modify its properties.
a) Heat treating
b) Forging
c) Welding
d) Annealing
160. It is performed by heating the steel above the upper critical temperature and holding it until the composition is uniform. Then the steel is cooled very
slowly in the furnace to below the lower critical temperature. Slow cooling to room temperature outside the furnace completes the process. This
treatment produces a soft, low-strength form of the material, free of significant internal stresses. Parts are frequently cold-formed or machined in the
annealed condition. How do you call this process?
a) Full annealing
b) Stress relief annealing
c) Normalizing
d) Tempering
161. This process is performed in a similar manner to annealing, but at a higher temperature, above the transformation range where austenite is formed,
o
o
approximately 1600 F (870 C). The result is a uniform internal structure in the steel and somewhat higher strength than annealing produces.
Machinability and toughness are usually improved over the as-rolled condition. How do you call this?
a) Full annealing
b) Stress relief annealing
c) Normalizing
d) Tempering
o
o
o
162. This process is usually performed immediately after quenching and involves reheating the steel to a temperature of 400 F to 1300°F (200 C – 700 C)
and then slowly cooling it in air back to room temperature. How do you call this process?
a) Full annealing
b) Stress relief annealing
c) Normalizing
d) Tempering
163. It refers to a group of steels typically used for cutting tools, punches, dies, shearing blades, chisels, and similar uses. What is this steel?
a) Tool steels
b) Wrought steels
c) Cast steels
d) High speed steels
164. The combinations of two or more materials, usually consisting of fiber and thermosetting polymer.
a) Brittle materials
b) Composite materials
c) Polymers
d) Ceramics
165. The corrosion of iron-base-alloys:
a) Rusting
b) Crazing
c) Chalking
d) Fritting
166. An iron in which most of the carbon is chemically combined with the iron.
a) Cast iron
b) Gray iron
c) White iron
d) Malleable iron
167. The modulus of elasticity for most metals in compression is usually taken as that in:
a) Tension
b) Bearing
c) Torsion
d) Yield
168. When the hole is smaller than the shaft, it will take force or pressure to put cold parts together. The allowance is said to be negative and is termed as
the:
a) Negative fits of metals
b) Positive
c) Interchangeable
d) Interference of metal
169. It is the relatively finely spaced irregularities of the surface.
a) Smoothness
b) Lay
c) Waviness
d) Roughness
170. Cold working of steel plates make the metal:
a) Tougher
b) More ductile
c) Harder
d) More malleable
171. This material group characterizes the high level of corrosion resistance offered by alloys. To classify this group, the alloy have a chromium content of at
least 10 %. How do you call this material?
a) Stainless Steel
b) Wrought steel
c) Structural steel
d) Chromium steel
172. This steel refers to a group of steels typically used for cutting tools, punches, dies, shearing blades, chisels, and similar uses.
a) Stainless Steel
b) Wrought steel
c) Structural steel
d) Tool steel
173. It is called as the fourth most commonly used metal in the world.
a) Zinc
b) Steel
c) Iron
d) Aluminium
174. This is a family of alloys of copper and zinc, with the content of zinc ranging from about 5% to 40%. It is often used in marine applications because of
its resistance to corrosion in salt water. How do you call this?
a) Brass
b) Copper
c) Bronze
d) Gold
175. This cast alloy is actually a high-strength form of brass because it contains zinc, the characteristic alloying element of the brass family. It contains
copper, zinc, tin, and manganese. What do you call this material?
a) Manganese bronze
b) Aluminum bronze
c) Nickel tin bronze
d) Tin bronze
176. What is a form of correction that develops on highly localized areas on a metal surface?
a) Crevice
b) Erosion
c) Galvanic
d) Apitting
177. This is a machining operation whereby the tools rotate while the feed is stationary. What do you call this machining operation?
a) Shaping
b) Milling
c) Turning
d) Reaming
178. Which of the following metals is easy to chisel?
a) Alloy steel
b) Stainless steel
c) Manganese steel
d) Cast iron
179. Which of the following contains a relatively large amount in ferrous metals?
a) Carbon
b) Manganese
c) Phosphorous
d) Sulfur
180. It is the peak of the stress-strain curve and sometimes simply called as tensile strength. How do you call this?
c) Endurance strength
d) Elastic strength
a) Yield strength
b) Ultimate tensile strength
181. That portion of the stress-strain diagram where there is a large increase in strain with little or no increase in stress is called as:
a) Yield strength
b) Ultimate tensile strength
c) Endurance strength
d) Elastic strength
182. That portion on the stress-strain curve where it deviates from the straight line is called which of the following?
a) Elastic limit
b) Proportional limit
c) Endurance limit
d) Yield point
183. At this point in the stress-strain curve, the material experiences some amount of plastic strain and thus will not return to its original shape after release
of the load.
a) Elastic limit
b) Proportional limit
c) Endurance limit
d) Yield point
184. In the Stress-strain diagram, what do you call the peak point on the stress-strain curve?
a) Yield point
b) Ultimate strength
c) Elastic limit
d) Proportional limit
185. At the highest point of the stress-strain curve during the test, what highest stress on a test bar of the material is measured?
a) Apparent stress
b) Ultimate stress
c) Elastic stress
d) Yield stress
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MACHINE DESIGN/SHOP PRACTICE
186. After peak of the curve in the stress-strain diagram is reached, there is a pronounced decrease in the bar’s diameter and that is referred to as:
a) Yielding down
b) Sloping down
c) Necking down
d) Deflection
187. How do you call a stress that is computed by dividing the load by the original cross-sectional area of the test bar before straining occurs?
a) Ultimate stress
b) Apparent stress
c) Elastic stress
d) Yield stress
188. This is that portion of the stress-strain diagram where there is a large increase in strain with little or no increase in stress. How do you call this portion?
a) Yield strength
b) Proportional limit c) Elastic limit
d) Ultimate strength
189. How do you call the point on the stress-strain curve where it deviates from a straight line?
a) Elastic limit
b) Proportional limit
c) Yield point
d) Ultimate strength
190. A four-bar mechanism in which one of the links can perform a full rotation relative to the other three links.
a) Geneva mechanism b) Crossover-position mechanism
c) Triple rocker mechanism
d) Grashof mechanism
191. “For a planar four-bar linkage, the sum of the shortest and longest lengths cannot be greater than the sum of the remaining two link lengths if there is to
be a continuous relative rotation between two members.” The preceding statement is known as:
a) Grubler’s Law
b) Coriolli’s Law
c) Grashof’s Law
d) Freudentein’s Law
192. The transformation of concepts and ideas into useful machinery is called as:
a) Design
b) Synthesis
c) Analysis
d) Theorem
193. It is a combination of mechanisms and other components that transforms, transmits, or uses energy, load, or motion for a specific purpose.
a) Mechanism
b) Engine
c) Machine
d) Linkage
194. It is defined as synergistic collection of machine elements; synergistic because as a design it represents an idea or concept greater than the sum of the
individual parts.
a) System of mechanisms
b) Mechanical system
c) Design system
d) Expert system
195. It may be defined the displacement per length produced in a solid as the result of stress.
a) Deformation
b) Elongation
c) Strain
d) Stress
196. The combination of applied normal and shear stresses that produces maximum principal normal stress or minimum principal normal stress, with a third
principal stress between or equivalent to the extremes.
a) Principal shear stress
b) Principal normal stress c) Maximum shear stress
d) Bending and shear stresses
197. It is a load applied transversely to longitudinal axis of member.
a) Combined loads
b) Concentrated load
c) Bending load
d) Distributed load
198. It is the intensity and direction of internal force acting at given point on particular plane.
a) Load
b) Strain
c) Stress
d) Sustained load
199. It is the capacity of a material to absorb energy when it is deformed elastically and then, upon unloading, to increase this energy.
a) Resilience
b) Toughness
c) Rigidity
d) Ductility
200. It is the strain energy per unit volume required to stress a material from an unloaded state to the point of yielding.
a) Modulus of roughness
b) Modulus of elasticity
c) Modulus of rigidity
d) Modulus of resilience
201. The ability of the material to absorb energy up to fracture.
a) Toughness
b) Rigidity
c) Resilience
d) Stiffness
202. The Maximum-Shear-Stress Theory, as a failure prediction theory, is also known as:
a) von Mises criterion
b) Tresca yield criterion
c) Coulomb-Mohr theory
d) Modified Mohr theory
203. A failure prediction theory, which states that a part subjected to any combination of loads will fail (by yielding or fracturing) whenever the maximum
shear stress exceeds a critical value.
a) Distortion-energy theory
b) Maximum-shear-stress theory
c) Internal friction theory
d) Modified Mohr theory
204. A theory in cyclic and impact loading, which states that damage at any stress level is proportional to number of cycles.
a) Miner’s Rule
b) Paris Power Law
c) Goodman Rule
d) Manson-Coffin Relationship
205. A set of specification for parts, materials, or processes intended to achieve uniformity, efficiency, and a specified quality.
a) Code
b) Standard
c) Law
d) Theorem
206. A set of specifications for the analysis, design, manufacture, and construction of something; the purpose of which is to achieve a specified degree of
safety, efficiency, and performance or quality.
a) Code
b) Standard
c) Law
d) Theorem
207. A sketch of a machine, a machine element, or part of a machine element that shows all acting forces, such as applied loads and gravity forces, and all
reactive forces.
a) Schematic diagram
b) Free body diagram
c) Moment diagram
d) Skeletal diagram
208. The property of a material that measures the degree of plastic deformation sustained at fracture.
a) Toughness
b) Stiffness
c) Ductility
d) Brittleness
209. Compounds of metallic elements, most frequently oxides, nitrides, and carbides.
a) Plastic
b) Polymers
c) Ceramics
d) Alloy
210. A material having different properties in all directions at point in solid.
a) Isotropic material
b) Anisotropic material
c) Orthotropic material
d) Ceramic material
211. A material having different properties in three mutually perpendicular directions at point in solid and having three mutually perpendicular planes of
material symmetry.
a) Orthotropic material
b) Isotropic material
c) Anisotropic material
d) Thermoplastic material
212. The combinations of two or more materials, usually consisting of fiber and thermosetting polymer.
a) Brittle materials
b) Composite materials
c) Polymers
d) Ceramics
213. It is a load that is applied slowly and is never removed. How do you call this?
a) Fluctuating load
b) Static load
c) Combined loads
d) Cyclic load
214. These are loads that vary during the normal service of the product. These loads are typically applied for quite a long time so the part experiences many
thousand or millions of cycles of stress during its expected life. How do you call these loads?
a) Cyclic loads
b) Repeated loads
c) Fluctuating loads
d) Static loads
215. This is the resulting stress when a part is subjected to a load that is applied slowly, without shock, and is held at a constant value. What is this stress?
a) Static stress
b) Repeated stress
c) Fatigue stress
d) Fluctuating stress
14
MACHINE DESIGN/SHOP PRACTICE
216. This is the stress when a load-carrying member is subjected to an alternating stress with a non-zero mean. How do you call this stress?
a) Fluctuating stress
b) Repeated stress
c) Fatigue stress
d) Static stress
217. A stress reversal occurs when a given element of a load-carrying member is subjected to a certain level of tensile stress followed by the same level of
compressive stress. If this stress cycle is repeated many thousands of times, the stress is call what?
a) Fatigue stress
b) Repeated and reversed stress
c) Static stress
d) Fluctuating stress
218. It is a loading when varying loads are applied that are not regular in their amplitude. How do you call this loading?
a) Random loading
b) Shock loading
c) Impact load
d) Static loading
219. It is the ability of a material to withstand fatigue loads. It is the stress level that a material can survive for a given number of cycles of loading. What is
this?
a) Endurance strength
b) Fatigue strength
c) yield strength
d) Ultimate strenght
220. In the Stress-strain diagram, what do you call the peak point on the stress-strain curve?
a) Yield point
b) Ultimate strength
c) Elastic limit
d) Proportional limit
221. What is the opposite of ductility?
a) Ductility
b) Brittleness
c) Toughness
d) Stiffness
222. It is the degree to which a material will deform before ultimate fracture. How do you call this?
a) Ductility
b) Brittleness
c) Toughness
d) Stiffness
44. This property indicates a material’s stiffness under shear loading, that is the resistance to shear deformation.
a) Modulus of elasticity
b) Young’s Modulus c) Poisson’s Ratio
d)Modulus of Rigidity
45. When a material is subjected to a tensile stain, there is a simultaneous shortening of the cross-sectional dimensions perpendicular to the direction of
tensile strain. The ratio of the shortening strain to the tensile strain is called as:
a) Modulus of elasticity
b) Young’s Modulus c) Poisson’s Ratio
d)Modulus of Rigidity
46. After peak of the curve in the stress-strain diagram is reached, there is a pronounced decrease in the bar’s diameter and that is referred to as:
a) Yielding down
b) Sloping down
c) Necking down
d) Deflection
47. How do you call a stress that is computed by dividing the load by the original cross-sectional area of the test bar?
a) Ultimate stress
b) Apparent stress
c) Elastic stress
d) Yield stress
48. This is that portion of the stress-strain diagram where there is a large increase in strain with little or no increase in stress. How do you call this portion?
a) Yield strength
b) Proportional limit c) Elastic limit
d) Ultimate strength
49. How do you call the point on the stress-strain curve where it deviates from a straight line?
a) Elastic limit
b) Proportional limit
c) Yield point
d) Ultimate strength
50. How do you call a point on the stress-strain curve at which point the material experiences some amount of plastic strain and thus will not return to its
original shape after release of the load?
a) Elastic limit
b) Proportional limit c) Yield point
d) Ultimate strength
51. It is an attempt to duplicate how the human mind works in computer processes. How do you call this?
a) Computed Aided Design
b) Artificial intelligence
c) Conceptual framework
d) Theoretical framework
52. This is an application of computer technology to planning, performing, and implementing the design process. What is this?
a) Computed Aided Design
b) Artificial intelligence
c) Conceptual framework
d) Theoretical framework
53. What is a design approach wherein all disciplines involved with a product are in the development process from beginning to end?
a) Concurrent Engineering
b) Reversed Engineering
c) Re-engineering
d) Machine Design
54. How do you call the transformation of concepts and ideas into useful machinery?
a) Engineering
b) Design
c) Machining
d) Modeling
55. How do you call a computer programs that solve specialized-problems on an expert level?
a) Artificial Intelligence
b) Computer Aided Design
c) Experts systems
d) Fault-free analysis
56. This is a statistical data used to identify the most likely failure modes. What is this?
a) Fault free analysis
b) Finite Element Analysis
c) Concurrent Engineering
d) Machine Element Function
57. This is a computational method used for solving complex shapes, such as those found in machinery; replaces the complex shape with a set of simple
elements interconnected at a finite set of a specific purpose. How do you call this?
a) Fault free analysis
b) Finite Element Analysis c) Concurrent Engineering
d) Artificial Intelligence
58. How do you call a combination of mechanisms and other components that transform, transmit, or use energy, load, or motion for a specific purpose?
a) Machine Element
b) Machine
c) Mechanism
d) Engine
59. What is a synergetic collection of machine elements?
a) Mechanical System
b) Measurement system
c) Control system
d) System Design
60. This is an additional capacity or incorporation of back up systems so that a component failure does not lead to catastrophic loss. How do you call this?
a) Redundancy
b) Prototyping
c) Machine Element Function
d) Drafting
61. How do you call a structural member designed to support loads perpendicular to its longitudinal axis?
a) Beam
b) Column
c) Shaft
d) Cantilever
62. What is a load applied transversely to longitudinal axis of member?
a) Bending load
b) Axial load
c) Torsional load
d) Simple load
63. How do you call the ability of a material to withstand load without failure?
a) Strength
b) Stress
c) Strain
d) Yield stress
64. It is the force or load applied to a material per unit area. What do you think it is?
a) Strength
b) Stress
c) Strain
d) Yield stress
65. It is the amount by which a body changes (shorten or lengthen) due to the application of load divided by the original length. What is this?
a) Strength
b) Stress
c) Strain
d) Yield stress
66. It is the maximum stress at which a material may be subjected without causing permanent deformation. What is this?
a) Elastic limit
b) Proportional Limit
c) Yield point
d) Ultimate strength
67. It is related to the ease with which a material can be machined to a good surface finish with reasonable tool life. What is this?
a) Machinability
b) Toughness
c) Endurance strength
d) Hardness
68. How do you call the ability of a material to absorb applied energy without failure?
a) Machinability
b) Toughness
c) Endurance strength
d) Hardness
69. It is the resistance of a material to indentation by penetration. What do you call this?
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MACHINE DESIGN/SHOP PRACTICE
a) Hardness
b) Machinability
c) Ductility
d) Toughness
70. What is the capacity of the material to absorb energy when it is deformed elastically and then, upon unloading, to release this energy?
a) Toughness
b) Ductility
c) Resilience
d) Strength
71. It is the strain energy per unit volume required to stress a material from an unloaded state to the point of yielding. How do you call this?
a) Modulus of elasticity
b) Modulus of rigidity
c) Modulus of resilience
d) Poisson’s Ratio
72. It is a theory stating that failure is caused by elastic energy associated with shear deformation. How do you call this theory?
a) Distortion-energy theory
b) Maximum-shear stress theory
c) Internal friction theory
d) Modified Mohr theory
73. A sketch of a machine, a machine element, or part of a machine element that shows all acting forces, such as applied loads and gravity forces, and all
reactive forces.
a) Schematic diagram
b) Free body diagram
c) Moment diagram
d) Skeletal diagram
74. The size to which limits or deviations is assigned and is the same for both members of the fit; it is the exact theoretical size.
a) Nominal size
b) Basic size
c) Maximum size
d) Minimum size
75. The algebraic difference between a size and the corresponding basic size.
a) Tolerance
b) Allowance
c) Deviation
d) Limit
76. The algebraic difference between the maximum limit and the corresponding basic size.
a) Fundamental deviation
b) Upper deviation
c) Lower deviation
d) Tolerance
77. The algebraic difference between the minimum limit and the corresponding basic size.
a) Fundamental deviation
b) Upper deviation
c) Lower deviation
d) Tolerance
78. Either the upper or the lower deviation, depending on which is closer to the basic size.
a) Fundamental deviation
b) Upper deviation
c) Lower deviation
d) Tolerance
79. The difference between the maximum and minimum size limits of a part.
a) Allowance
b) Tolerance
c) Deviation
d) Basic size
80. The property of a material that measures the degree of plastic deformation sustained at fracture.
a) Toughness
b) Stiffness
c) Ductility
81. Compounds of metallic elements, most frequently oxides, nitrides, and carbides.
a) Plastic
b) Polymers
c) Ceramics
d) Brittleness
d) Alloy
82. A material having different properties in all directions at point in solid.
a) Isotropic material
b) Anisotropic material
c) Orthotropic material
d) Ceramic material
83. A material having different properties in three mutually perpendicular directions at point in solid and having three mutually perpendicular planes of
material symmetry.
a) Orthotropic material b) Isotropic material
c) Anisotropic material
d) Thermoplastic material
84. The combinations of two or more materials, usually consisting of fiber and thermosetting polymer.
a) Brittle materials
b) Composite materials
c) Polymers
d) Ceramics
85. A principle or method that a deflection at any point in bar is equal to sum of deflections caused by each load acting separately.
a) Summation Method
b) Method of balancing
c) Method of superposition
d) Shear and Moment diagram method
86. It is a form of correction that develops on highly localized areas on a metal surface.
a) Crevice
b) Erosion
c) Galvanic
d) Apitting
87. The corrosion of iron-base-alloys:
a) Rusting
b) Crazing
c) Chalking
d) Fritting
88. An iron in which most of the carbon is chemically combined with the iron.
a) Cast iron
b) Gray iron
c) White iron
d) Malleable iron
89. The modulus of elasticity is a measure of which of the following?
a) Accuracy
b) Quality
c) Stiffness
d) Rigidity
90. The modulus of elasticity for most metals in compression is usually taken as that in:
a) Tension
b) Bearing
c) Torsion
d) Yield
91. It is the ratio of moment and stress.
a) Strain
b) Contraction
c) Proportional constant
d) Section Modulus
92. For a symmetrical cross-sectional beam, what is the value of flexural stress when the vertical shear stress is at maximum?
a) Infinity
b) Maximum
c) Zero
d) Minimum
93. It is the permissible variation of the size of a dimension.
a) Tolerance
b) Fits
c) Limits
d) None of above
94. When the hole is smaller than the shaft, it will take force or pressure to put cold parts together. The allowance is said to be negative and is termed as
the:
a) Negative fits of metals
b) Positive
c) Interchangeable
d) Interference of metal
95. It is the relatively finely spaced irregularities of the surface.
a) Smoothness
b) Lay
c) Waviness
d) Roughness
96. It is the irregularities or departures from the nominal surface of greater spacing than roughness.
a) Smoothness
b) Lay
c) Waviness
d) Roughness
97. How do you call a combination of two or more previously defined loads?
a) Bending load
b) Combined load
c) Distributed load
d) Cyclic load
98. The considered maximum safe center distance of sprockets because very long center distance causes catenary tension in the chain.
a) 70 pitches
b) 80 pitches
c) 60 pitches
d) 50 pitches
99. Cold working of steel plates make the metal:
a) Tougher
b) More ductile
c) Harder
d) More malleable
100. The property that characterizes a material ability to be drawn onto a wire:
16
MACHINE DESIGN/SHOP PRACTICE
a) Ductility
b) Thermal conductivity
c) Tensile strength
d) Endurance limit
101. It is any process in which steel is subjected to elevated temperatures to modify its properties.
a) Heat treating
b) Forging
c) Annealing
d) Soldering
102. This material group characterizes the high level of corrosion resistance offered by alloys. To classify this group, the alloy have a chromium content of at
least 10 %. How do you call this material?
a) Stainless Steel
b) Wrought steel
c) Structural steel
d) Chromium steel
103. This steel refers to a group of steels typically used for cutting tools, punches, dies, shearing blades, chisels, and similar uses.
a) Stainless Steel
b) Wrought steel
c) Structural steel
d) Tool steel
104. It is called as the fourth most commonly used metal in the world.
a) Zinc
b) Steel
c) Iron
d) Aluminium
105. This material is widely used in its nearly pure form for electrical and plumbing applications because of its high electrical conductivity and good corrosion
resistance.
a) Brass
b) Copper
c) Bronze
d) Gold
106. A steel rod on bridge must be made to withstand a pull of 5,000 lbs. Find the diameter of the rod assuming a factor of safety of 5 and ultimate stress of
64,000 psi.
a) 0.75 in
b) 0.84 in
c) 0.71 in
d) 0.79 in
107. If the ultimate shear strength of a steel plate is 42 000 psi, what force is necessary to punch a 0.75 diameter hole in a 0.625 in thick plate?
a) 63 000 lbs
b) 61 800 lbs
c) 68 080 lbs
d) 66 800 lbs
108. What force P is required to punch a ½ in. hole on a 3/8 in. thick plate if the ultimate shear strength on the plate is 42,000psi?
a) 24,940 lbs
b) 24,620 lbs
c) 24,960 lbs
d) 24,740 lbs
o
109. A 2.5 in. diameter by 2 in. long journal bearing is carrying a 5,500 lb load at 3600 rpm using SAE 40 lube at 200 F through a single hole at 25 psi.
Compute the bearing pressure.
a) 1100 psi
b) 1000 psi
c) 900 psi
d) 950 psi
110. What modulus of elasticity in tension is required to obtain a unit deformation of 0.00105 m/m from a load producing a unit tensile stress of 44,000 psi?
6
6
6
6
b) 41.202 x10 psi
c) 43.101 x10 psi
d) 41.905 x10 psi
a) 42.300 x10 psi
10
111. The diameter of a brass rod is 6 mm. What force will it stretch by 0.2% of its length? EBRASS = 9 x 10 Pa.
a) 5090 N
b) 5060 N
c) 9050 N
d) 6050 N
112. A steel tie rod is to withstand a pull of 3,000 lbs. Find the diameter of the rod assuming a yield stress of 48,000 psi and a factor of safety of 5.
a) 16 mm
b) 20 mm
c) 25 mm
d) 63 mm
113. Which of the following equations is the equation of polar moment of inertia of a hollow shaft?
a)
J=
[
π
(D o )4 − (D i )4
32
]
b)
J=
[(D
64
π
4
4
o ) − (D i ) ]
c)
J =
π D3o
⎡1 − β4 ⎤⎦
32 ⎣
d)
J =
4
π D3o ⎡ ⎛ Di ⎞ ⎤
⎢1 − ⎜
⎟ ⎥
16 ⎢ ⎝ Do ⎠ ⎥
⎣
⎦
114. A sketch of a machine, a machine element, or part of a machine element that shows all acting forces, such as applied loads and gravity forces, and all
reactive forces.
a) Schematic diagram
b) Free body diagram
c) Moment diagram
d) Skeletal diagram
115. The three moment equation may be used to analyse:
a) Tapered column
b) Continuous beam
c) Composite beam
17
d) Axially end loaded beam
MACHINE DESIGN/SHOP PRACTICE
JCSF ENGINEERING REVIEW CENTER
# 2 Alvaran’s Apartment, Purok 7, Halang
City of Calamba, Laguna
MACHINE DESIGN AND SHOP PRACTICE
(Refreshers Trivia # 8 for September 2012 Board Examination)
Prepared by: Jose R. Francisco, PME
September 2012
MULTIPLE CHOICE QUESTIONS
Select the best answer from each of the following questions. On the answer sheet provided, shade the box that corresponds to your choice. Strictly no
erasures allowed.
1. Electric furnaces can usually operate up to a temperature of:
A. 1000°C
B. 1250°C
C. 1700°C
D. 2200°C
2. Which of the following materials is used for automobile engine block?
a) Alloy steels
b) Gray cast iron
c) Copper
d) Titanium-clad steel
3. Which of the following is used for wrenches and automobile chassis?
a) Alloy steels
b) Gray cast iron
c) Copper
d) Titanium-clad steel
4. Which of the following is the base material used for light-emitting diode (LED)?
a) Barium titanate
b) Gallium arsenide
c) Silica
d) Phenolics
5. Which of the following materials is used for capacitors in microelectronics?
a) Barium titanate
b) Gallium arsenide
c) Silica
d) Phenolics
6. Which of the following materials is used for optical fibers in information technology?
a) Silica
b) Polyethylene
c) Epoxy
d) Phenolics
7. Which of the following materials is used for food packaging?
a) Silica
b) Polyethylene
c) Epoxy
d) Phenolics
8. Which of the following materials is used for encapsulation of integrated circuits (IC)?
a) Silica
b) Polyethylene
c) Epoxy
d) Phenolics
9. Material used for window glasses?
b) Al2O3-MgO, SiO2
c) Silica
d) Gallium Arsenide
a) SiO2-Na2O-CaO
10. Which of the following is the material used for refractories (i.e. heat-resistant lining of furnaces) for combining molten metal.
b) Al2O3-MgO, SiO2
c) Silica
d) Gallium Arsenide
a) SiO2-Na2O-CaO
11. Generally for the melting of cast iron, electric furnaces are not used because:
A. Cast iron is in the form of broken pieces
B. The rate of heating required for melting cast iron cannot be provided by electric furnace
C. Cast iron requires higher temperature for heating D. It is expensive to use electricity for melting cast iron
12. Material used as electrical conductor wire.
a) Alloy steels
b) Gray cast iron
c) Copper
d) Titanium-clad steel
13. A material or adhesives used for joining plies in plywood.
a) Silica
b) Polyethylene
c) Epoxy
d) Phenolics
14. Electric indirect furnace is normally used for melting of:
A. alloy steels
B. cast steels
C. non-ferrous metals
D. all of these
15. Pit furnace can be used for the melting of:
A. cast iron
B. aluminum
C. brass
D. any of these
16. Oil fired furnaces are generally used for the melting of :
A. cast steel
B. alloy steel
C. cast iron
D. non-ferrous metals
17. Flux used in cupola while melting cast iron.
A. lime stone
B. coke slurry
C. molasses
D. any of these
18. The flux used when sulfur is to be removed from cast iron while melting the same in cupola.
A. Molasses
B. sodium carbonate with lime stone
C. Zinc sulphate with lime stone
D. none of these
19. In aluminum foundry, the flux used for removing dissolved hydrogen and the entrapped dross.
A. nitrogen
B. helium
C. chlorine
D. any of these
20. In melting of aluminum, the dross is consists of:
A. oxides of aluminum, magnesium, etc. B. sand and dust
C. lighter material
D. none of these
21. Use of flux in melting of magnesium.
A. separate out impurities
B. prevents burning of magnesium alloy
C. facilitates production of sound castings
D. all of the above
22. In copper alloy foundry, it is used to prevent the molten metal from being oxidized.
A. charcoal
B. bone ash
C. phosphorous
D. calcium carbonate
23. The disadvantage in using wood as the material for pattern making.
A. its low cost
B. its different strength along the grains and across the grains
C. it gets warped when not stored properly
D. it is lighter than the metal to be cast
24. Wood that can be used for making patterns.
A. mahogany
B. pine wood
C. teak wood
D. any of these
25. Plaster patterns and core boxes are made of:
A. plaster of Paris
B. gypsum cement
C. bone china clay
D. white powder
26. Phenolic thermo-setting plastics are finding application in pattern making because:
A. they do not absorb moisture
B. they are strong
C. they are resistant to wear D. they have all these qualities
27. Wax patterns are used in:
A. non-ferrous casting B. investment casting process
C. machine moulding process
D. all of these
28. If an old casting is to be used as a pattern, to account for various allowances.
A. casting is shaken while withdrawing from mould
B. the surfaces are lagged with thin strips of wood or leather
C. the casting are cleaned and made smooth
D. to provide screws, holes can be drilled and tapped in the castings
29. The metal sprayed on wooden pattern when wooden patterns with metallic coating are to be used.
A. bismuth
B. zinc
C. aluminum
D. any of these
1
MACHINE DESIGN/SHOP PRACTICE
30. Consumable pattern are made of:
A. polystyrene
B. wax
C. plaster of Paris
D. any of these
31. Pattern where there is no need for the withdrawal of pattern from the mould.
A. wax pattern
B. hollow pattern
C. patterns with core
D. consumable pattern
32. Relative density of polystyrene often used as a consumable pattern material.
3
3
3
3
B. 120 to 125 kg/m
C. 1120 to 1250 kg/m
D. 2240 to 2500 kg/m
A. 20 to 50 kg/m
33. Polystyrene is generally available in the form of:
A. plates
B. cylindrical bars
C. square sections
D. trapezoid moulds
34. While selecting wood for patter, one should:
A. discard the rot
B. select the cross-grained woods
C. select the freshly filled wood
D. discard the seasoned wood
35. Wood that is difficult to machine.
A. freshly failed wood
B. old and used wood
C. kiln dried wood
D. seasoned wood
36. On drying, wood:
A. expands
B. shrinks
C. changes color
D. none of the above
37. In small casting, which of the following allowance can be ignored?
A. shrinkage allowance
B. rapping allowance
C. draft allowance
D. machining allowance
38. Property enabling the sand mass not to fall out of the moulding box but is held firmly in it when the moulding box is lifted.
A. porosity of sand
B. adhesiveness of sand
C. refractoriness of sand
D. plasticity of sand
39. Property of sand that requires a predetermined shape under pressure and retains the same when pressure is removed.
A. cohesiveness
B. plasticity
C. refractoriness
D. none of these
40. The property of sand to withstand the high temperature of the molten metal without fusing or breakdown.
A. refractoriness
B. cohesiveness
C. porosity
D. adhesiveness
41. Clay content of green sand.
A. 1 to 3 percent
B. 5 to 10 percent
C. 18 to 30 percent D. 30 to 50 percent
42. The water content of green sand.
A. 1 to 2 percent
B. 6 to 8 percent
C. 12 to 18 percent
D. 20 to 25 percent
43. The principal ingredients of moulding sand.
A. silica sand, carbon and water
B. silica sand, clay and water
C. silica sand, dust and carbon
D. silica sand, carbon, hydrocarbon and moisture
44. Which of the following sands must possess high refractories?
A. backing sand
B. parting sand
C. facing sand
D. all of these
45. Clay used for foundry sand.
A. Kaolinite
B. Montmorillonite
C. Illite
D. any of these
46. Grain shape of sand particles that is least preferred for foundry sand.
A. round
B. angular
C. compound
D. none of these
47. It is used on mould for magnesium castings to prevent metal mould reactions.
A. boric sulphur
B. molasses
C. charcoal
D. all of these
48. It is used to obtain fine surface finish in ferrous castings.
A. ground pitch
B. sea coal
C. gilsonite
D. any of these
49. The burnt on sand causes difficulty in:
A. machining of castings
B. removal of castings from moulds
C. separation of sand and castings after pouring
D. all of these
50. Heat storage capacity of moulding sand can be increased by adding:
A. graphite
B. chromites
C. magnesium powder
D. any of these
51. Addition of saw dust to moulding sand increases its:
A. gas permeability
B. refractoriness
C. cohesiveness
D. all of these
52. Shatter test is a measure of:
A. sand toughness
B. sand adhesiveness
C. sand cohesiveness
D. none of these
53. Which of the following is a screen?
A. shovel
B. riddle
C. reamer
D. slick
54. A slick is mainly used for:
A. makings openings in mould
B. providing openings in the mould
C. repairing and finishing of mould
D. removing pattern from the mould
55. Swab is used for:
A. applying water to the mould around the edge of the pattern
B. shaking pattern to facilitate its withdrawal from the mould
C. repairing and finishing of moulds
D. none of these
56. It facilitates shaking and lifting large patterns from the mould.
A. trowel
B. swab
C. bellows
D. ripping plate
57. Chaplets are:
A. core binders
B. core supports
C. core projections
D. mould seats to support core
58. Chaplets are provided to:
A. reduce core sag
B. support heavy cores
C. compensates for inadequate coreseats
D. mould seats to support core
59. Chaplets are made of:
A. core sand
B. organic matter
C. wood
D. metal
60. Tin coated low carbon steel chaplets are used in:
A. ferrous foundries
B. non-ferrous foundries
C. wood
D. both A and B
61. Which of the following statement about gates is incorrect?
A. the size of gate depends upon the rate of solidification
B. a small gate is used for castings which solidify rapidly
C. more than one gate may be used to feed a fast freezing casting
D. a gate should not have sharp edges
62. Of the following metals, the pouring rate should be minimum for:
A. steel
B. aluminum
C. brass
D. cast iron
63. The defect produced when dross and slag along with liquid metal reach the mould cavity.
A. misrun
B. inclusions
C. blow holes
D. all of these
64. Slag and dross can be removed by:
A. skimming from the molten metal
B. using bottom pouring ladle
C. using pouring basin in place of a pouring cup
D. any of these
2
MACHINE DESIGN/SHOP PRACTICE
65. Padding is:
A. a method for production of chilled castings
B. an extra support for thin casting
C. an extra metal added to the original uniform section of the casting
D. none of these
66. The solidification shrinkage of magnesium alloys is about:
A. 0.1 percent
B. 1 percent
C. 4 percent
D. 14 percent
67. The solidification shrinkage of carbon steel is around:
A. 0.1 to 0.2 percent
B. 0.5 to 1 percent
C. 2 to 4 percent
D. 8 to 10 percent
68. Melting point of copper
A. 665°C
B. 1083°C
C. 1444°C
D. 1576°C
69. Melting point of gold
A. 1063°C
B. 1444°C
C. 2100°C
D. 3300°C
70. Which of the following metals has the lowest melting point?
A. aluminum
B. magnesium
C. brass
D. silver
71. Which of the following metals has the lowest melting point?
A. magnesium
B. silver
C. zinc
D. tin
72. Metal that has the highest melting point.
A. tungsten
B. nickel
C. steel
D. cast iron
73. A pit furnace can be used for the melting of:
A. cast iron
B. brass
C. aluminum
D. all of these
74. Pig iron is obtained from iron ore in a blast furnace by the process of:
A. oxidation
B. reduction
C. carbonation
D. desulphurization
75. A blast furnace operates continuously for:
A. hours together
B. days together
C. weeks together
D. months together
76. Slag in a blast furnace is:
A. lighter than molten iron
B. heavier than molten iron
C. weighted as molten iron
D. thicker than molten iron
77. Hot blast of air is supplied to the blast furnace through:
A. stoves
B. tuyers
C. prop
D. spout
78. If ash content of coke used in cupola is high, then:
A. melting rate will be low
B. more of flux will be required
C. castings produced will have blow holes
D. carbon content of castings will be low
79. Coked used in cupola is in the form of:
A. coal dust
B. pulverized coal
C. lumps
D. any of these
80. Thermal efficiency of cupola is in the range of:
A. 80 to 90 percent
B. 60 to 75 percent
C. 50 to 65 percent
D. 30 to 50 percent
81. The disadvantage of hot blast cupola.
A. low coke consumption
B. reduced silicon loss
C. reduced output silicon loss
D. all of these
82. The advantage of oxygen enriched cupola.
A. higher temperature of molten iron
B. high efficiency of cupola
C. reduced heat loss in waste gases
D. all of these
83. During the passage of molten metal through the coke, the carbon percentage of the molten metal increases. The absorption of carbon depends on:
A. size of the coke
B. temperature
C. time allowed for molten metal to remain in the cupola
D. all of these
84. As a result of melting of cast iron in cupola, which of the following constituent undergoes least change in its percentage?
A. silicon
B. sulphur
C. carbon
D. phosphorous
85. As a result of melting of cast iron in cupola, the percentage of all the following constituents decreases, EXCEPT:
A. silicon
B. sulphur
C. carbon
D. phosphorous
86. Inoculants used to produce ductile iron.
A. magnesium
B. carbon
C. graphite
D. fluorides
87. Contraction of metal starts at the end of:
A. liquid stage
B. mushy stage
C. plastic stage
D. solid stage
88. Permanent mould casting is also known as:
A. gravity die casting
B. chill casting
C. slush casting
D. short casting
89. The advantage of permanent mould casting.
A. reduced labor charges
B. reduced mould cost
C. dense, fine grained structure
D. all of these
90. The advantage of centrifugal casting.
A. dense castings
B. elimination of cores
C. mass production with reduced rejection possible
D. all of these
91. Metals that can be cast in plaster moulds.
A. yellow brass
B. manganese
C. aluminum bronzes
D. aluminum bronze
92. Investment casting is also known as:
A. lost wax casting
B. lost pattern casting
C. hot investment casting
D. any of these
93. Which of the following is not necessarily the characteristic of investment casting?
A. extreme dimensional accuracy
B. excellent surface finish
C. low cost
D. no disfiguring parting line as found on casting made by cope and drag method
94. Inoculants are added to aluminum mainly for:
A. grain refinement
B. directional solidification
C. purification
D. all of these
95. Magnesium-aluminum alloys are grain refinement by addition of:
A. sulphur
B. manganese
C. carbon
D. tin
96. The pouring temperature for gray cast iron.
A. 1510 to 1532 °C
B. 1455 to 1495 °C
C. 1400 to 1465 °C
D. 1250 to 1290 °C
97. In case of copper, the pouring temperature is:
A. 1450 °C
B. 1260 °C
C. 1160 °C
D. 1060 °C
98. Lowest pouring temperature alloy.
A. tin bronze
B. phosphor bronze
C. monel metal
D. cupro nickel alloy
99. For aluminum alloys grain refinement can be achieved using:
A. titanium
B. boron
C. zirconium
D. any of these
100. Which of the following process is used for melting of steels?
A. LD process
B. Kaido process
C. Duplex process
D. all of these
3
MACHINE DESIGN/SHOP PRACTICE
101. In case of arc\furnaces electric supply for electrodes consists of:
A. low voltage and high current
B. high voltage and high current
C. high voltage and low current
D. low voltage and low current
102. Composition of cast iron can be better controlled when melted in:
A. pit furnace
B. cupola
C. arc furnace
D. none of these
103. Die casting dies are generally made of:
A. cast iron
B. aluminum alloys
C. alloy steels
D. bonze
104. Die casting is generally not used for:
A. zinc based alloy
B. aluminum based alloys
C. non-ferrous metals
D. cast iron
105. Chemical dippling of die casted parts is usually done for:
A. flash removal
B. dimensional stability
C. corrosion protection
D. none of these
106. The binder used in case of carbon dioxide moulding.
A. sodium silicate
B. China clay
C. coal dust
D. graphite
107. Aluminum castings are not prepared by:
A. Inert gas metal arc welding
B. braze welding
C. soldering
D. all of these
108. All of the following are non-destructive method of testing the castings. EXCEPT:
A. pressure test
B. ultrasonic test
C. tensile test
D. dye penetrant inspection
109. Which of the following test on casting that is based on sound?
A. impact test
B. percussion test
C. radiographic
D. magnetic particle inspections
110. In radiography test in castings, which if the following rays are never used?
A. X-rays
B. beta rays
C. gamma rays
D. all of these
111. Tempering is generally done to reduce the following, EXCEPT:
A. brittleness
B. ductility
C. hardness
D. tensile strength
112. Annealing temperature of aluminum.
A. 325°C
B. 425 °C
C. 525 °C
D. 625 °C
113. Annealing of aluminum castings:
A. reduces tensile strength
B. improves ductility C. relieves micro stresses D. mechanical properties change
114. The percentage of sulphur in pig iron.
A. 0.01 to 0.3%
B. 0.3 to 0.55%
C. 0.6 to 0.79%
D. 0.8 to 0.9%
115. Pure iron melts at 1500°C. presence of carbon:
A. reduces the melting point
B. increases the melting point
C. does not change the melting point
D. not relevant to melting point
116. Presence of sulphur in cast iron:
A. retards fluidity
B. promotes brittleness
C. promotes oxidation
D. all of these
117. Grey cast iron is:
A. costlier than other varieties of cast iron
B. poor in machining ability
C. resistant to shock
D. least fluid in molten condition
118. Graphitic cast iron is:
A. hard
B. non-machinable
C. high in compressive strength
D. low n damping capacity
119. White cast iron contains:
A. free graphite
B. cementite
C. free carbon
D. none of these
120. Addition of nickel in cast iron increases:
A. hardness
B. corrosion resistance
C. ensile strength
D. all of these
FOR READING AND FAMILIARIZATION
121. Molybdenum up to 1.5% is added to cast iron to:
A. increase strength
B. reduce wear resistance
C. increase machinability
D. all of these
122. Very powerful carbide formed in cast iron.
A. silicon
B. vanadium
C. chromium
D. nickel
123. Which of the following cast iron is resistant to attack by sea water?
A. low chromium cast iron
B. low nickel cast iron
C. low sulphur cast iron
D. low phosphorous cast iron
124. High silicon irons are:
A. resistant to wear
B. machinable
C. malleable
D. brown in color
125. Variety of cast iron that can be forged.
A. grey cast iron
B. high silicon cast iron
C. wrought cast iron
D. all of these
126. Alloy containing 70% nickel and 30% copper is known as:
C. N-c alloy
D. permalloy
A. hastalloy
B. monel metal
127. Non-uniform distribution of alloying components, inclusions and impurities in an ingot or casting.
A. segregation
B. ageing
C. inoculation
D. bleeding
128. Casting made in relatively simple shapes and designed for subsequent fabrication by rolling, forging etc.
A. rolls
B. chills
C. ingots
D. pigs
129. The phenomenon under which the strain of a material varies under constant stress.
A. creep
B. strain hardening
C. Buchinger’s effect
D. Hysteresis
130. It is the reason why an elliptic cross section is more economical for the arms of pulley.
A. ease of manufacture
B. its section modulus about minor axis being greater than that about major axis
C. its moment of inertia being larger about major axis D. Stronger
131. Basquin’s equation is used to design:
A. for completely reversible loads
B. parts subjected to indefinite number of cycles
C. parts for definite number of cycles
D. for low cycle fatigue
132. Autofretting is a
A. type of heat treatment
B. type of corrosion
C. type of prestressing
D. method to reduce stress concentration
133. It is a loading of component such that the variable stress is less than endurance limit for some time.
A. prestressing
B. training
C. underloading
D. low cycle fatigue
134. Endurance strength is 100% for a component with :
A. ground finish
B. mirror finish
C. machined surface
D. hot rolled surface
135. It is advisable to use a rectangular key of width/thickness ratio
A. less than one
B. more than one
C. one
D. none of the above
4
JCSF ENGINEERING REVIEW CENTER
# 2 Alvaran’s Apartment, Purok 7, Halang
City of Calamba, Laguna
MACHINE DESIGN/SHOP PRACTICE TRIVIA
(Refreshers Trivia 9)
Prepared by: Jose R. Francisco, PME
September 2012
MULTIPLE CHOICE QUESTIONS
Select the best answer from each of the following questions. On the answer sheet provided, shade the box that corresponds to your choice. Strictly no
erasures allowed
1.
2.
3.
4.
5.
Which of the following is the allowable tensile strength of the steel plates?
2
2
2
b) 379.31 N/m
c) 296.12 N/m
a) 396.41 N/m
Which of the following standard SAE designation of manganese steel?
a) 13xx
b) 11xx
c) 10xx
d) 310.11 N/m
2
d) 8xx
o
Compute the torque received by the motor shaft running at 4250 rpm. Transmitting 11 Hp, through a 10 in diameter 20 involute gear. The shaft is
supported y ball bearings at both ends and the gear is fixed at the middle of 8” shaft length.
a) 163 in lb
b) 132 in lb
c) 167 in lb
d) 138 in lb
The SAE 2340 shafting contains how man percent nickel?
a) 3.85 Ni
b) 3.25 to 3.75% Ni
c) 4% Ni
d) 3.84% Ni
Which of the following standard SAE designation for chromium steel?
a) 92xx
b) 3xxx
c) 5xxx
d) 11xx
6.
In general, alloys with high nickel content retain toughness to quiet low temperatures up to how many degrees Fahrenheit?
a) -380
b) -260
c) -400
d) -320
7.
The length of the hub should not be made lesser than the face width of the gear. Hub length usually vary from 1.25D to 2D where D is the shaft
diameter. What should be the reasonable diameter of steel hub?
a) 2D
b) 1.55D
c) 1.8D
d) 1.20D
Torsional deflection is a significant consideration in the design of shaft and the limit should be in the range of how many degee/foot of length?
a) 0.4 to 1
b) 0.08 to 1
c) 0.1 to 1
d) 0.6 to 1
8.
9.
If the pitch of a screw is 2/9 find the thread per inch.
a) 0.34
b) 5.4
c) 4.5
d) 17
10. Steel spring material is usually hardened from 400 to 500 BHN and the carbon content is in the range of how many percent?
a) 0.50 to 0.90%
b) 0.45 to 0.48
c) 0.96 to 0.97
d) all of these
11. Shafts readily available in the market are made in many ways and wide variety of material composition. It is likely be cold drawn carbon steel in size
smaller than ______ inches diameter.
a) 3.75
b) 5
c) 4
d) 5 ½
12. Plain carbon steel standard designation SAE _______.
a) 6xxx
b) 10xx
c) 13xx
d) 2xxx
2
13. If the inertia is 90 lb ft and the speed of the driven shaft is to be increased from 0 to 2500 rpm in 5 seconds, shaft material is of SAE 4140 with
2
yield strength of 110000 lbs./in , find the clutch starting torque in in.-lb ft.
a) 159
b) 146
c) 128
d) 191
14. How many 5/6 inch holes can be punch in one motion in a steel plate made of SAE 1010 steel 7/16 inch thick using a force of 55 tons. The ultimate
strength for shear is 50 ksi and use 2 factor of safety.
a) 5.8
b) 5
c) 3.7
d) 6.5
15. Which of the following cannot be used in drilling machine?
a) reaming
b) lapping
c) spot facing
16. A kilowatt is equal to:
a) 8851.2 in-lb/sec
b) 57 BTU/min
17. Molybdenum-chromium-nickel steel designation.
a) SAE48xx
b) SAE56xx
d) broaching
c) 1140 joule/sec
d) 44.200 ft-lb/min
c) SAE43xx
d) SAE46xx
18. Single forces which produces the same effect upon a mass replacing two or more forces acting together is called:
a) vector
b) component of forces
c) resultant
d) resolution
19. Permissible variation of the manufactured/machined dimension is called:
a) intolerance firs
b) allowance
c) deviation
d) tolerance
20. Peculiar strength of the metal to resist being crushed:
a) shear strength
b) compressive strength
c) ultimate strength d) elastic limit
21. What pressure is required for punching a hole 2” dia thru ¼” steel paltes?
a) 40 tons
b) 45 tons
c) 50 tons
d) 35 tons
22. What is the working strength of a 2” bolt which is screwed tightly in a packed joint when the allowable stress is 12,000 psi.
a) 20.4 ksi
b) 23.4 ksi
c) 22.4 ksi
d) 18 ksi
23. Determine the bursting steam pressure of a steel shell with a diameter of 10 inches and made of ¼ thick steel plate. The joint efficiency is at 70%
and the tensile strength is 60 ksi,
a) 4200 psi
b) 42.8 ksi
c) 10.54 ksi
d) 8500 ksi
24. Commonly used by steel melter as deoxidizer because of its availability and cheap price.
a) silicon
b) zinc
c) aluminum
d) manganese
25. Curve formed by a path of a point on a straight line as it rolls along a convex base curve. The base curve is usually a circle and generally used as
the profile of gear tooth.
a) axial plane
b) arc or recess
c) involute
d) arc of action
26. Resultant of two or more component forces is called:
a) composition of forces
b) component
c) resultant
d) collinear of forces
27. A material having a high electrical resistance and should not be used for conductor of electric current.
a) alloyed magnesium
b) nickel
c) silicon base alloy
d) zinc
28. It improves red hardness of steel.
a) silicon
b) cobalt
c) lead
d) manganese
29. Designated pipe color used in communication.
a) silver gray
b) bare
c) aluminum gray
d) white
30. The design stress and facto of safety are related in the following manner.
a) design stress = ultimate stress/factor of safety
b) ultimate stress = factor of safety/design stress plus concentration factor
c) factor of safety = design stress/ultimate stress
d) design stress = factor of safety/time stress concentration factor
31. Not adaptable to welding due to low tensile strength and poor ductility etc.
a) copper parts
b) aluminum parts
c) cast iron materials
32. Bearing surface that completely surrounds the journal is also called:
a) offset bearing
b) centrally loaded bearing
c) full bearing
d) bronze parts
d) babbit bearing
33. The purpose of lubrication is as mentioned except:
a) to lighten the load
b) prevent adhesion
c) prevent corrosion/oxidation
d) cool the moving elements
34. Tools usually used in wood pattern making in foundry shop.
a) saws and chisel
b) knives and drills
c) band saw
d) drill machine
35. It is a plane perpendicular to the axial plane to the pitch plane in gears the parallel axes and the plane of rotation coincides.
a) tangent plane
b) transverse
c) straight plane
d) reference plane
36. A 36 tooth pinion with a turning speed of 300 rpm drives 120 tooth gear of 14 ½” d involute full depth pressure angle. What would be the speed of
the driven gear?
a) 1000 rpm
b) 90 rpm
c) 100 rpm
d) 140 rpm
37. Several force which can be combined is called:
a) resultants
b) components
c) composition of forces
d) collinear forces
38. The surface along the fillet curves or between the fillets radius of the two adjacent tooth or a gear:
a) bottom land
b) fillet
c) flank
d) top land
39. Ideal herringbone gear helix is in the range of:
a) bottom land
b) fillet
c) flank
d) top land
40. ideal herringbone gear helix is in the range of:
a) 30 to 45
b) 25 to 30
c) 35 to 50
d) 15 to 20
41. A three extension coil spring are hooked in series hat support a single weight of 100 kgs. The first spring is rated at 0.400 kg/mm and the other 2
lower spring is rated at 0.64 kg/in. Compute the total deflection.
a) 263 mm
b) 156 mm
c) 268 mm
d) none of these
42. he lack of backslash in a spur gear design/operation may result to:
a) overloading
b) all of these
c) jamming
d)overheating
43. The distance from a point on a screw thread to a corresponding point on the next thread measure along the axis.
a) flank
b) crest
c) lead
d) pitch
44. As recommended the center to center distance between sprockets should not be less than ______times the bigger sprocket.
a) 2.216
b) 1 ½
c) 1 ¾
d 2.59
45. Machine shop instrument for checking the flatness of plane surfaces to 10ths of thousandths of a centimeter.
a) blade type micrometer b) planimeter
c) dial caliper
d) micrometer
46. Molybdenum steel standard designation SAE.
a) 88xx
b) 40xx
c) 48xx
d) 46xx
47. Also called eccentrically loaded bearing is:
a) full bearings
b) partial bearing
c) offset bearing
d) fitted bearing
48. In the selection of wire rope, regular lay means wires and strands are arranged in the following manner.
a) twisted in the same direction
b) twisted in opposite direction c) twisted in any direction d) twisted in along direction
49. In involute teeth, the pressure angle is often defined as the angle between the line of action and the line of tangent to the pitch circle is also termed
as:
a) helix angle
b) angle of obliquity
c) angle of recess
d) arc of action
50. Instantaneous center is also called:
a) centro
b) virtual center
c) rotople
d) all of these
51. What is the stress to strain ratio within the elastic limit?
a) elastic limit
b) elasticity
c) modulus of elasticity
d) compressive ratio
52. A material plane was subjected to a load. When the load was removed the strain disappeared. From the structural change which of the following
can be considered about this material?
a) it does not follow Hooke’s Law b) it is elastic
c) it has high modules of elasticity
d) it is plastic
53. Allowance added in the casting pattern to compensate for the contraction of metal
a) tapering allowance
b) finish allowance
c) shrinkage allowance
d) draft pattern
54. Ratio of the angle of action to the pitch angle
a) contact angle
b) ratio of gearing
c) approach ratio
55. General purpose grade of steel used for broiler plate, structural etc. usually with carbon content of:
a) 0.20 to 0.30% C
b) 0.35 to 0.50% C
c) 0.15 to 0.25% C
d) module
d) all of these
56. The angle made by the helix of the thread(in a straight thread) at the pitch diameter with a plane perpendicular to the axis called:
a) angle of thread
b) lead angle
c) truncation
d) lead
57. The principle materials used in the production of metal working tools:
a) high carbon steel
b) titanium, phosphorus
c) tungsten, silicon, hadfield Mn
d) vanadium, chromium,
molybdenum
58. In the interest of design simplification and good kinematic compromise bevel gears adopted a standard pressure angle of _____ degrees.
o
o
b) 141/2 involute full depth
c) 20
d) 171/2
A) 20 involute stub
59. The property of material that relates the lateral strain to longitudinal strain.
a) stress
b) poisson’s ratio
c) strain
d) endurance limit
60. It is generally recommended and normal for a designer to add a hunting tooth to evenly distribute the wear on meshing teeth like a 53 teeth gears
with 30 teeth pinion. Find the mesh with same pair of teeth again.
a) 120
b) 61
c) 81
d) 53
61. The shaft whose torque varies from 2000 to 6000 in lbs has 1 ½ in in diameter and 60000 psi yield strength. Compute for the shaft mean average
stress.
a) 6036 psi
b) 5162 psi
c) 6810 psi
d) 5550 psi
62. The angle made by the helix of the thread (in a straight thread) at the pitch diameter with a plane perpendicular to the axis is called:
a) lead angle
b) lead
c) truncation
d) angle of thread
63. The rule of thumb in journal bearing design; the clearance ratio/clearance should be.
a) 0.0090
b) 0.0010
c) 0.0042
d) 0.00120
64. The moment of inertia of a rectangle whose base is “b” height “h” about its base is:
3
3
3
3
b) bh 24
c) bh /12
d) bh /3
a) bh /4
65. Cold rolled shafting is not available in diameter larger than:
a) 6 inches
b) 6 ½ inches
c) 5 inches
d) 5 ½ inches
66. Height of tooth above pitch circle or the radial distance between pitch circle and top land of the tooth.
a) top root
b) land
c) addendum
d) hunting tooth
67. The function of clutch in the machine tool is?
a) lowering of drive speed
b) to disconnect or connect at will the drive
c) alignment of drive shaft
d) to insure that two shaft line up at high speed
68. A resulting force that replace two or more forces acting together
a) vector
b) resultant
b) couple
d) equilibrant
69. Stress relieving is also ______ for the purpose of reducing the internal stresses of steel material/metal.
a) normalizing
b) annealing
c) tempering
70. Matensite (stainless steel) contains 4 to 26% Cr. And a maximum of ______% nickel.
a) 2.5
b) 3.5
c) 3.25
d) all of these
d) 2.0
71. Matensite (stainless steel) contains 4 to 26% Cr. And a maximum of ______% nickel.
a) 2.5
b) 3.5
c) 3.25
d) 2.0
72. Compute the deflection of a 18 coils helical sornig having a load of 100 kgs. The modulus of elasticity in shear of spring is 96.62 GPa, OD of 9 256
cm and with diameter if 925 mm. the spring is square and ground ends.
a) 9 mm
b) 112 mm
c) 101 mm
d) 14 mm
73. A flanged bolt coupling has ten (10) steel 25.4 mm diameter bolts evenly tighten around a 415 mm bolt circle. Determine the torque capacity of the
2
connection if the allowable shearing stress in the bolt is 50 MN/m .
a) 59.95 KN-m
b) 46.15 KN-m
c) 52.6 KN-m
d) 43.8 KN-m
74. The material that can cut/wear hardest substance subjected to:
a) carbide
b) tungsten
c) abrasive
d) vanadium
75. A ridge of uniform section in the form of helix cut around the circumference of a cylinder and advancing along the axis.
a) thread roots
b) screw threads
c) helix thread
d) chamfers
76. Cast iron flywheels are commonly designed with factor of safety of:
a) 10 to 13
b) 10 to 14
c) 10 to 12
77. Class of material exhibiting decreased electrical conductivity with increasing temperature.
a) aluminum
b) metals
c) p-type semiconductors
d) 8 to 13
d) n-type conductors
78. The welding made along edges of two parallel plates is called:
a) groove joint
b) edge joint
c) fillet joint
d) corner joint
79. Not part and in fact should not used in the steel melting process:
a) coke
b) zinc
c) silicon
d) aluminum
80. Role of thumb in calculating the equipment foundation mass should be ______ times the weight of the machinery it is supposed to support.
a) 3-5
b) 3-9
c) 3-6
d) 2-4
o
81. The strength of non-ferrous alloys is at maximum at room temperature while that of ferrous metal has a maximum strength at ____ F
a) 400
b) 450
c) 1200
d) 350
82. The ratio of stress acting on a elastic substance to the decrease in volume per unit volume.
a) bulk modulus
b) elastic limit
c) modules of resilence
d) modules of elasticity
83. The normal helix angles in helical gear is recommended in the range of _____degrees,
a) less than 18
b) 15 to 25
c) 20 to 35
84. Type of bolt commonly used in construction that is threaded in both ends.
a) stud bolt
b) hex bolt
c) acne threaded bolts
85. It is rigid piece serves to transmit force from a piece another piece or to cause/control motion
a) follower
b) cam motion
c) crank
d) 20 to 30
d) square threaded bolt
d) link
86. A 20 kgs. cast iron piece rest on a plain horizontal aluminum surface. To move the object it needs a force of 7 lbs. The density of Al is 0.98 lb/in
3
and iron is 0.260 lb/in .
a) 0.172
b) 1.601
c) 0.186
d) 0.160
87. Which of the following is an iron based alloy containing 9-16% chromium?
a) Mn Hadfield steel
b) stainless steel
c) chrome-moly steel
d) high chrome steel
88. Shafting up to 3 inches in diameter is usually made from cold rolled steel and the common biggest diameter of cold rolled steel is:
a) 4 ¼ inches
b) 6 ¾ inches
c) 6 7/8 inches
d) 5 inches
3
89. It is deal for maximum quietness in sprockets drive operation to choose ____ or more teeth.
a) 24
b) 27
c) 18
d) 21
90. All associated with standard material specification except:
a) American Iron and Steel Institute
b) Society of Automotive Engineers
c) Southeast Asia Iron and Steel Institute
d) American Society for Testing Materials
91. For stable equipment foundation the total combined engine driven equipment and foundation center of gravity must be kept below the foundation’s
too that usually about ______ times the usual total combined weight of the machinery it is supposed to support.
a) 3 to 4
b) 2 to 4
c) 3 to 7
d) 3 to 5
92. A cylinder tank with 10” inside diameter contains oxygen gas at 2500 psi. Calculate the required wall thickness in (mm) under stress of 28 000 psi.
a) 11.34 mm
b) 12.44 mm
c) 10.24 mm
d) 10.54 mm
93. The process of peening the joint portion immediately after the welding greatly improves the fusion structures avoids possible cracking, avoids
possible distortion etc. Peening can also ______ process at the same time.
a) tempering
b) normalizing
c) martampering
d) annealing
94. What do you call he distance between center nearest each other in adjacent rows?
a) pitch
b) margin
c) back pitch
95. Which of the following is a major alloy in tool steel?
a) Cr
b) cobalt
c) Fen
d) diagonal pitch
d) Mn
96. Should two equal and opposite collinear forces is added to the forces already in equilibrium, which of the following statement is true?
a) unbalanced moment is maintained
b) equilibrium is maintained
c) equilibrium is disturbed
d) it creates an unbalanced situation
97. In pressure vessels, which of the following resists internal pressure through beding?
a) shell-type element
b) can type element c) plate-type element
d) spherical type element
98. Which of the following flanges is suitable for low and moderate pressure?
a) Ring-flange
b)Lap joint flange
c) Tapered-hub flange
d) Welding neck type
99. It is the process of pre-stressing or over-stressing of a hollow cylindrical member beyond the elastic range.
a) pesstagge
b) autofrettage
c) stress relieving
d) countersinking
100. It is the phenomena occurring when two touching surfaces have a high contact pressure and when these surfaces have minute relative motion.
a) pretending
b) fretting
c) friction
d) carrving
JCSF ENGINEERING REVIEW CENTER
# 2 Alvaran’s Apartment, Purok 7, Halang
City of Calamba, Laguna
MACHINE DESIGN/SHOP PRACTICE TRIVIA
(Refreshers Trivia 10)
Prepared by: Jose R. Francisco, PME
September 2012
MULTIPLE CHOICE QUESTIONS
Select the best answer from each of the following questions. On the answer sheet provided, shade the box that corresponds to your choice. Strictly no
erasures allowed
1.
A double thread ACME screw driven by a motor at 400 rpm raises the attached load of 900 kg at a speed of 10 m/min. The screw has a pitch
diameter of 36 mm; the coefficient of friction on threads is 0.15. The friction torque on the thrust bearing of the motor is taken as 20 % of the total
input. Determine the lead angle.
o
o
o
o
b) 14.265
c) 15.462
d) 16.452
a) 12.465
V
10
=
= 0.025 m = 25 mm
n 400
−1 ⎛ L ⎞
−1 ⎛ 25 ⎞
o
For the lead angle, λ = tan ⎜
⎜ πD ⎟⎟ = tan ⎜⎝ 36π ⎟⎠ = 12.465
⎝ m⎠
Solution: For the lead,
2.
L=
A simple band brake, installed on a 500mm brake drum, is used to absorb a torque of 250 N-m. If the coefficient of friction and the contact angle
between the band and drum are 0.2 and 180º, respectively, and that the length of the brake arm is twice the drum diameter, determine the
minimum braking force applied at the free end of the brake arm.
a) 721.5 N
b) 752.1 N
c) 275.1 N
d) 572.1 N
F2 (a )
Solution: F1 = e fθ = 1.874 : → F
: a = D : → L = 2D
b min =
F2
L
3.
→ Fb min
2T
F2
D
=
=
= 572.1N
2 2(1.874 − 1)
Find the maximum permissible concentrated bending load that may be carried by a simply-supported shaft of 2-ft span of 2-in. diameter if the
allowable flexural stress is 6,000 psi.
a) 854.7 lb
b) 485.7 lb
c) 587.4 lb
d) 785.4 lb
Solution: Bending moment is maximum if F is applied at mid span.
σ=
4.
Mc 32M
=
I
πD 3
→ M=
FL
4
→
32(F)(24)
= 6000
4π(23 )
→ F = 785.4lb.
A bar of rectangular section is made of AISI C1020 steel (Su = 65,000 psi), and is subjected to a tensile load of 8 tons. If the width of the bar is 1.5
times the thickness, find the bar dimensions if the factor of utilization is 0.25 based upon the ultimate strength.
a) 0.5” x 0.75”
b) 1” x 1.5”
c) 1.5” x 2.25”
d) 0.81” x 1.22”
Solution: Factor of Utilization =
1
Factor of Safety
s=
S
F
= u = ( U.F x S u ) :
N
1 .5 b 2
8 x 2000
1 .5 b 2
= 0.25 x 65000 : → b = 0.81 in.
and b x h = 0.81” x 1.22”
5.
A low carbon steel sheet 3/8 in. thick, lined with aluminum 1/8 in. thick, is used to form a connecting rod. Steel has a modulus of elasticity of 30 x
6
6
10 psi, while aluminum of 10.3 x 10 psi. If the aluminum has a tensile stress of 10,000 psi, what is the corresponding stress of the steel sheet?
a) 12,961 psi
b) 96,122 psi
c) 29,126 psi
d) 26,191 psi
Solution: σ = E ε: With constant strain ε, σAL/EAL = σST/EST.
6.
A 9 cm square bar is to be held firmly at one end and to support a load of 2000 kg at the other end. The bar is to be 1.5 m long, and is to be made
from steel with yield strength of 500 MPa. What factor of safety is used in the design if the stress concentration factor is 1.3?
a) 2.34
b) 3.45
c) 2.67
d) 1.59
K Mc
Solution: S Y = t
N
I
Where, M = FL = 29 430 000 N ⋅ mm
then
7.
Thus, σST = (30/10.3) x (10,000) = 29,126 psi.
N=
Sy I
K t Mc
I=
a4
= 5 467 500 mm 4
12
c = a / 2 = 45 mm
thus : N = 1.59
A round bar made from SAE 1025 low carbon steel is to support a direct tensile load of 222.449 kN. Using a factor of safety of 4 and assuming that
the stress concentration factor is 1.45, what is the required outside diameter in mm of the member if the ratio of the inside and outside diameter is
0.75? For the material, the yield strength is 276 MPa.
a) 283.34
b) 116.64
c) 98.76
d) 156.54
Solution:
Sy
N
8.
=
KtF
4K t F
=
=
2
2
A
π DO − Di
(
)
4K t F
πD O
⎛ Di 2
1−
⎜ D 2
o
⎝
2⎜
thus : D o = 116.64 mm
⎞
⎟
⎟
⎠
A car is moving at 96.6 kph when the brakes are suddenly locked and the car begins to skid. If it takes 2 seconds to slow down the car to 4.83 kph,
how far in meters will it have traveled before it car comes to a halt?
a) 53.64
b) 276
c) 137
d) 876
Solution: Velocities, in m/s, Vi = 96.6 kph = 26.83 m / s
Vf = 48.3 kph = 13.42 m / s
Distance, s = Vf − Vi = 0 − (26.83) = 53.64 m
2a
2(− 6.7 )
Acceleration, a = Vf − Vi = 13.42 − 26.83 = − 6.71 m / s 2
2
t
9.
2
What is the weight of a 2 steel plates sized ¾” x 3” x 20 ft?
a) 1836 lb
b) 3667 lb
Solution: Density or specific weight of a steel plate = 0.283 lb/ft
(
2
2
c) 1698 lb
d) 1848 lb
3
)
W = γ V = 0.283 lb / in 3 (0.75 in.)(3)(12 in )(20 )(12 in )(2 ) = 3667.68 lb
10. What load, in kN, must be applied to a 25 mm round steel bar 2.5 m long (E = 207 GPa) to stretch the bar 1.3 mm?
a) 52.84
b) 60
c) 53.048
d) 42.562
⎛π 2⎞
⎛π⎞
2
⎜ D ⎟E
⎜ ⎟ (25) (207 000 )(1.3)
AE
⎝4
⎠
⎝4⎠
δ=
δ=
= 52 837.66 N = 52.84 kN
Solution: F =
L
L
2 500
2
11. A car is travelling at 90 kph when the brakes are applied. If it travels a distance of 60 meters before coming to a stop, what is its acceleration m/s ?
a) – 7.08
b) 6.36
c) – 5.21
d) 5.76
Solution:
⎛ 1 hr ⎞
V 2 − V12 0 − (25)2
⎟⎟ = 25 m / s a = 2
V1 = (90 kph )(1000 m / km )⎜⎜
=
= − 5.20 m / s 2
3600
s
(
)
2
S
2
60
⎝
⎠
6
12. A steel shaft 1.75 inches in diameter transmits 40 Hp at 1800 rpm. Assuming a modulus of rigidity of 12 x 10 psi, find the torsional deflection of the
shaft in degrees per foot length.
a) 0.0871
b) 0.00871
c) 0.871
d) 0.000871
Solution:
θ
T
32T
=
=
=
L JG πD 4 G
⎛ 63 000 Hp ⎞
⎡ 63000(40 ) ⎤
32⎜
32 ⎢
⎟
⎥
n
⎝
⎠=
⎣ 1800 ⎦ = 0.00013 radian = 0.0871o
4
4
πD G
π (1.75) 12 x 10 6
(
)
o
13. A spur pinion rotates at 1600 rpm and transmits 50 kW to a mating gear. The pitch diameter of the pinion is 100 mm, and the pressure angle is 20 .
Determine the tangential load, in N.
a) 5 968
b) 5790
c) 5900
d) 5098
⎛ 30P ⎞ 2 ⎡ 30(50 ) ⎤
2⎜
⎟
⎢
⎥
2T
⎝ πn ⎠
⎣ π (1600) ⎦
=
=
= 5.968 kN = 5 968 N
Solution: Ft =
(0.10)
D
D
14. A flywheel weighing 450 kg has a radius of 375 mm. How much energy, in N-m, does the flywheel loss from 180 rpm to 168 rpm?
a) 1472.33
b) 1541.33
c) 1451.33
d) 1433.51
⎛ 180 ⎞
⎟ = 7.069 m / s
⎝ 60 ⎠
⎛ 168 ⎞
V2 = 2πRN 2 / 60 = 2π (0.375)⎜
⎟ = 6.597 m / s
⎝ 60 ⎠
Solution: V1 = 2πRN 1 / 60 = 2π (0.375) ⎜
∆KE =
(
)
[
]
m V12 − V22
450 (7.069 )2 − (6.597 )2
=
= 1451.33 N ⋅ m
2
2
15. A punch punches 1-in diameter hole in a steel plate ¾ inch thick every 10 sec. The actual punching takes 1 sec. The ultimate shear strength of the
2
plate is 60,000 psi. The flywheel of the punch press has a mass moment of inertia of 500 in-lb-sec and rotates at a mean speed of 150 rpm. What
is the speed fluctuation, in rpm?
a) 65.4 rpm
b) 64.5 rpm
c) 6.749 rpm
d) 67.49 rpm
(
)
⎛ ω + ω2 ⎞
⎛1⎞
⎛1⎞
∆KE = ⎜ ⎟ I ω12 − ω12 = ⎜ ⎟ I (ω1 − ω2 )(ω1 + ω2 ) = I (ω1 − ω2 ) ⎜ 1
⎟ = I (ω1 − ω2 ) ω
2
2
2 ⎠
⎝
⎝ ⎠
⎝ ⎠
2πN 2π (150)
=
= 15.71 rad / s
Mean angular velocity, ω =
60
60
Solution:
Punching Force, F = s u (πdt ) = (60 000 )(π )(1)(0.75) = 141 371.67 lb
Kinetic Energy, ∆KE = 1
2
(F) t = (1 2 )(141 371.67 ) ⎛⎜ 0.75 ⎞⎟ = 4417.86 ft ⋅ lb
⎝ 12 ⎠
(
4417.86 ft ⋅ lb)(12 )
∆KE
=
= 6.749 rad / s = 64.5 rpm
Speed Fluctuation, (ω1 − ω 2 ) =
Iω
500 in ⋅ lb ⋅ s 2 (15.71)
(
)
16. With the present water interruptions prevailing in Metro Manila, you have been asked to design an upright cylindrical water tank 6 meters in
diameter and 6 meters high, vented, and to be filled completely with water. Determine the minimum thick ness of the tank plate if the stress is
limited to 40 Mpa.
a) 3.3 mm
b) 4.4 mm
c) 5.5 mm
d) 8.8 mm
Solution: p
= ρgh = (1000)(9.8066 )(6 ) = 58 839.6 Pa = 58.8396 kPa
t=
pD (58.8396 )(6 )
=
= 0.00441 m = 4.41 mm
2s t
2 (40 000 )
17. In a high-rise building, the elevator rises 366 meters with an operating speed of 5 meters per second and reaches full speed in 10.68 meters. The
2
loaded elevator weighs 2000 kg. Determine the acceleration of the elevator in m/sec .
a) 1.17
b) 2.17
c) 3.17
d) 4.17
Solution:
a=
V22 − V12 (5)2 − (0 )2
=
= 1.17 m / s 2
2S
2 (10.68)
18. A disc clutch has 6 pairs of contacting friction surfaces with an outside diameter of 200 mm and an inside diameter of 100 mm. The coefficient of
friction of the clutch materials is 0.4 and the axial force is 1500 N. The shaft speed is 1200 rpm. Determine the Hp that can be transmitted by the
clutch assuming uniform pressure.
a) 35.2 Hp
b) 23.5 Hp
c) 47.2 Hp
d) 27.4 Hp
Solution: Friction Radius (Uniform pressure), rf =
3
3
2 ⎛⎜ ro − ri ⎞⎟ ⎛ 2 ⎞ ⎡ (100)3 − (50)3 ⎤
= ⎜ ⎟⎢
⎥ = 77.78 mm
3 ⎜ ro2 − ri2 ⎟ ⎝ 3 ⎠ ⎣⎢ (100)2 − (50)2 ⎦⎥
⎝
⎠
Friction Power or Transmitted Power or Power Capacity,
P=
Where,
π n Tf
πn
(Ff rf n f ) = π n (f Fa rf n f ) = π(1200) (0.4)(1.5)(0.07778)(6)
=
30
30
30
30
P = power capacity, kW
Fa = axial load, kN
Ff = friction force, kN
Rf = friction radius or mean radius, m
P = 35.19 kW = 47.2 Hp
Tf = torque capacity, kN-m
nf = no. of pairs of contacting friction surfaces
19. What load of P may be applied to a butt weld between two plates 0.5 inch thick and 5 inches long if the allowable working stress for tensile loading
is 13000 psi?
a) 32 500 lb
b) 25 000 lb
c) 44 000 lb
d) 50 000 lb
Solution: For butt weld,
P = s t t L = (13 000 psi )(0.5 inch )(5 inches ) = 32 500 lb
20. A constant force of 150 N is applied tangentially to a wheel of 140 mm in diameter. Determine the work done, in J, in 12 revolutions of the wheel.
a) 729 J
b) 792 J
c) 972 J
d) 927 J
Solution:
W = F ⋅ s = (150 N )(π)(0.14 m )(12) = 791.68 J
21. Determine the force applied tangentially to a bar of screw-jack at a radius of 800 mm if the torque required is 600 N-m.
a) 705 N
b) 507 N
c) 750 N
d) 570 N
Solution:
F=
T 600
=
= 750 N
R 0.80
22. A thin hollow sphere of radius 254 mm and thickness 2.54 mm is subjected to an internal pressure of 789 kPa. What is the maximum normal stress
on an element of the sphere?
a) 39.45 kPa
b) 39.45 MPa
c) 34.95 kPa
d) 34.95 MPa
Solution:
sL =
pD (789 kPa )(2)(0.254 m )
=
= 39 450 kPa = 39.45 MPa
4t
4 (0.00254)
23. A 1.52 m diameter steel pipe, 9.52 mm thick, carries water under a pressure head of 168 m. Determine the hoop stress in the steel.
a) 131.5 MPa
b) 135.1 MPa
c) 153.1 MPa
d) 113.5 MPa
Solution:
st =
pD ρghD (1000 )(9.8066 )(168)(1.52 )
=
=
= 131 523.81 kPa = 131.524 MPa
2t
2t
2(0.00952 )(1000)
24. A wire of length 2.5 m has a percentage strain of 0.012 % when loaded with a tensile force. Determine the extension of the wire.
a) 0.10 mm
b) 0.20 mm
c) 0.30 mm
d) 0.40 mm
Solution:
⎛ 0.012 ⎞
δ = Strain x L = ⎜
⎟ (2.5 m )(1000) = 0.3 mm
⎝ 100 ⎠
o
25. Determine the minimum whole depth of spur gear of 20 involute type with diametral pitch of 6 and circular pitch of 0.1309 inch.
a) 0.5593 inch
b) 0.5395 inch
c) 0.3595 inch
d) 0.3955 inch
Solution: From Vallance, page 262:
h=
2.157 2.157
=
= 0.3595 inch
pd
6
26. A gas engine valve spring is to have a mean diameter of 3.81 cm and a wire diameter of 0.635 cm. The maximum load it will have to sustain is
45.15 kg with corresponding deflection of 1.27 cm. The spring is to be made of tempered steel wire. Determine the no. of coils to be used. Use
modulus of rigidity equal to 80 GPa.
a) 7.4
b) 8.1
c) 10.4
d) 14.4
Solution:
C=
Dm
3.81
=
=6
d
0.635
δ=
8FC 3 n
Gd
n=
δGd
8FC
3
=
(
)
0.0127 80 x 10 9 (0.00635)
8(45.15)(9.8066 )(6 )3
= 8.43
Actual Number of coils = n + 2 8.43 + 2 = 10.43
2
27. Determine the developed acceleration of a roller coaster in m/s when the velocity is 20 m/s at a radius of curvature of 6500 cm.
2
2
2
2
b) 6.15 m/s
c) 6.51 m/s
d) 5.61 m/s
a) 6.15 m/s
Solution:
Weight = Centrifugal Force
ma =
mV 2
r
a=
V 2 (20 )2
=
= 6.15 m / s 2
r
65
28. A solid shaft is to be used to transmit 75 kW at 550 rpm. If the shaft design stress will not exceed 26 MPa, what is the diameter of the shaft?
a) 63.42 mm
b) 42.63 mm
c) 36.42 mm
d) 64.23 mm
Solution:
30P 30(75)
T=
=
= 1.3022 kN ⋅ m
πn
π(550 )
1
⎛ 16T ⎞ 3
⎟ = 63.42 mm
D = ⎜⎜
⎟
⎝ πs s ⎠
3
29. A 48-inch diameter spoked steel flywheel (γ = 0.28 lb/in ) having a 12-in wide x 10-in deep rim rotates at 200 rpm. Determine the kinetic energy of
this flywheel. Neglect the weight of its spokes and hub.
a) 84,448 ft-lb
b) 68,488 ft-lb
c) 42,248 ft-lb
d) 53,123 ft-lb
⎛ n ⎞
⎛ 38 ⎞⎛ 200 ⎞
V = π D m ⎜ ⎟ = π⎜ ⎟⎜
⎟ = 33.16 fps
⎝ 60 ⎠
⎝ 12 ⎠⎝ 60 ⎠
Solution: D m = D o − t = 48 − 10 = 38 inches
Wf = γV = 0.28(π) (38)(12 )(10 ) = 4011.2lb
KE =
1 Wf 2
⎛ 1 ⎞ ⎛ 4011.2 ⎞
2
V = E punching = ⎜ ⎟ ⎜
⎟ (33.16) = 68 488 ft ⋅ lb
2 g
⎝ 2 ⎠ ⎝ 32.2 ⎠
30. A square bar of wrought iron, 2 inches on each side, is raised to a temperature of 100 deg F above its normal. If held so that it cannot expand, what
-6
6
stress will be induced in it? k = 6.8 x 10 per deg F & E = 30 x 10 psi
a. 17,400 psi
b. 18,400 psi
c. 19,400 psi
d. 20,400 psi
Solution: Induced Stress,
(
)(
)
s = k E (t 2 − t 1 ) = 6.8 x 10 −6 30 x 10 6 (100 ) = 20 400 psi
4
31. The valve push rod for an overhead valve engine is ¼ inch in diameter and 14 inches long. Find the moment of inertia of the rod in inches .
-4
-5
-4
-6
b) 1.917 x 10
c) 3.83 x 10
d) 3.83 x 10
a) 1.917 x 10
Solution:
I=
πD 4 π(0.25)4
=
= 1.917 x 10 − 4 in 4
64
64
32. A disc clutch having an outside diameter of 32 cm and an inside diameter of 12.7 mm is connected to an engine that turns at 750 rpm. The
2
coefficient of friction is 0.6 while the pressure between the friction surfaces is 2 kg/cm . Determine the force on the clutch petal necessary to
disengage the clutch disc from the engine.
a) 2621.7 kg
b) 3248.4 kg
c) 2524.2 kg
d) 1355.1 kg
Solution:
[(
)]
F = pA = p π R 2 − r 2 = 1355.14 kg
o
33. A helical gear of 10 inches pitch diameter has a helix angle of 30 , and there are 30 teeth. Find the value of the normal circular pitch.
a) 0.9069 inch/tooth
b) 0.6909 inch/tooth
c) 0.6096 inch/tooth
d) 0.9906 inch/tooth
Solution:
Pc =
πD π (10 )
=
= 1.0472 inches / tooth
T
30
(
)
Pcn = Pc cos ψ = 1.0472 cos 30o = 0.9069 inch / tooth
o
34. A parallel helical gear set was a 17-tooth pinion driving a 34-tooth gear. The pinion has a right-hand helix angle of 30 , a normal pressure angle of
o
20 , and a normal diametral pitch of 5 teeth/in. Find the axial circular pitches.
a) 1.2566 inches/tooth
b) 1.6625 inches/tooth
c) 1.6526 inches/tooth
d) 1.6256 inches/tooth
Solution:
Pc =
Pcn
0.62832
=
= 0.72552 inch / tooth
cos ψ cos 30o
Pa =
Pc
0.72552
=
= 1.2566 inches / tooth
tan ψ
tan 30o
35. It is a typical of material used for cylinder block.
a) Forged steel
b) Drop-forged, heat-treated steel\
c) Cast iron and coated with chrome or molybdenum
d) Cast iron
36. Which of the following is a material used for a piston ring?
a) Forged steel
b) Drop-forged, heat-treated steel\
c) Cast iron and coated with chrome or molybdenum
d) Cast iron
37. Which of the following is the typical material used for an engine crank shaft?
a) Forged steel
b) Heat-treated steel
c) Cast iron
d) Wrought iron
38. What is the function of a governor?
a) Store energy and give up whatever needed
b) Regulate the speed during one cycle of a prime mover
c) Increase variation of speed
d) Adjust variation of speed by varying the input to the engine
39. What is a machine used in testing steel generally strike the specimen with energy from 220 to 265 ft-lb?
a) Izod test
b) Charpy test
c) Rockwell test
d) Test blockd
40. Almost always the soldering materials are a combination of which of the following alloys?
a) Lead and tin
b) Tin and antimony
c) Lead and antimony
d) Both a, b & c
41. To ensure an adequate factor of safety in the design of a shaft with standard keyway, the key width should be about:
a) One half of the shaft diameter
b) One fourth of the shaft diameter
c) One eighth of the shaft diameter
d) One third of the shaft diameter
42. This is defined as the cutting time to reach a predetermined wear, called the tool wear criterion.
a) Wear duration
b) Cycle time
c) Tool life
d) Life cycle
43. Machining operations with the proper application of a cutting fluid generally has the following attributes except:
a) Higher cutting speeds
b) Higher feed rates
c) Lengthened tool life
d) Higher cutting accuracy
44. A material of construction (only developed commercially in the late 1940’s concurrently with zirconium) offers the unique combination of wide
ranging corrosion resistance, low density, and high strength.
a) Tungsten
b) Titanium
c) Vanadium
d) Molybdenum
45. Which of the following is the lightest of all structural metals?
a) Aluminum
b) Copper
c) Magnesium
d) Manganese
46. This is a type of welding whereby a wire or powder from the nozzle of a spray gun is fused by a gas flame, arc or plasma jet and the molten
particles are projected in a form of spray by means of compressed air or gas. How do you call this type of welding?
a) Metal spray welding
b) Electro-slug welding
c) Electro-beam welding
d) plasma arc welding
47. Which of the following does not belong to foundry or metal casting shop?
a) Core-making machine
b) Forging machine
c) Shake-out machine
d) Molding machine
48. Which of the following is a suitable method to check the eccentricity of a shaft?
a) Bench target and scriber
b) Bench top and tachometer
c) Bench side and calliper
d) Bench centers and dial indicator
49. This is a work supporting device which is bolted to the saddle of the lathe machine. It travels with the cutting tool, and used to prevent the springing
away of the work piece from cutting tool. How do you call this part?
a) Tool post
b) Carriage stop
c) Follower rest
d) Rubber-flex collets
50. Which of the following raw materials are used in the foundry molding operation?
a) Silica sand, linseed oil, & flour
b) Silica sand, paste, & graphite electrode
c) Silica sand, lime, flour
d) Silica sand, bentonite, flour/paste, and water
51. Which of the following is not part of a micrometer calliper?
a) Head screw
b) Thimble
c) Spindle
d) Anvil
52. The flux that should be avoided in soldering electrical connection or commutator wires as it tends to corrode the connections.
a) Acid fluxes
b) Salt ammoniac
c) Zinc chloride
d) Sodium chloride
53. It is a lathe machine operation used to produce a flat surface at the end of the part such as parts that are attached to other components, or to
produce grooves for o-ring seats.
a) Boring
b) Knurling
c) Facing
d) Parting
54. The most important operations in manufacturing is hole making. This can be done by which of the following?
a) Drilling machine
b) Sawing machine
c) Boring mills
d) Milling machine
55. It is a machine operation used to produce regularly shaped, roughness on cylindrical surfaces, as in making knobs. How do you call this operation?
a) Milling
b) Sawing
c) Drilling
d) Knurling
56. Which of the following material properties is adversely affected by grain refinement?
a) Creep resistance
b) Tensile strength
c) Ductility
d) yield strength
57. Hard solder is made of which of the following?
a) Tin and zinc
b) tin and copper
c) Copper and zinc
d) Tin and lead
58. Which of the following is the unit of mass moment of inertia?
2
2
b) kg/m
c) kg
d) N-m
a) kg-m
59. Which of the following is the unit of Young’s modulus of elasticity?
a) Dimensionless
b) Pascal
c) Metter
d) Newton
60. When a lathe tool bit burns, it means that the:
a) Speed is too low
b) Material is too hard
c) Speed is too fast
d) Material can’t be cut
61. The area of the machine shop whose metal is being melted to form a new shape.
a) Foundry area
b) Tool and die
c) Welding area
d) Mass production area
62. A corrosion occurs within or adjacent to a crevice formed by contact with another piece of the same or another metal.
a) Pitting
b) Galvanic
c) Erosion
d) Crevice
63. Which of the following is not part of a headstock?
a) Anvil
b) Spindle
c) Motor
d) Back gear
64. It refers to any layer or deposit of extraneous material on a heat-transfer surface.
a) Low line
b) Pressure drop
c) Fouling
d) Scaling
65. Have the same thermal and minimum film thickness limitation as sleeve bearing.
a) Ball bearing
b) Roller bearing
c) Thrust bearing
d) Oil whip
66. An oil storage tank roof formed to approximately a spherical surface, supported only at its periphery.
a) Self-supporting umbrella roof
b) Self-supporting cone roof
c) Self-supporting
d) Supported cone roof
67. What is a unit deformation?
a) Torsion
b) Strain
c) Stress
d) Shear
68. Accident prevention is:
a) An association of employers, organization & individuals
b) A job of a safety director
c) The Foreman’s responsibility just as much as production
d) The responsibility of top management
69. Alloy steel known for its resistance to corrosion, abrasion and wear that is usually ideal for mill grinding of ore in cement and concentrator
application. It is usually combined with molybdenum to increase the depth hardening.
a) Manganese chromium steel
b) Chromium-moly steel
c) Chrome-nickel-moly steel
d) Manganese-moly steel
70. Cutting of internal threads of a work piece can be produced by which of the following?
a) Milling
b) Tapping
c) Boring
d) Reaming
71. Which of the following milling operations is used to produce curved profiles, with cutters that have specially shaped teeth?
a) Form
b) Straddle
c) End
d) Slab
72. In screw threads, what is a pitch?
a) The distance from a point on one thread to a corresponding point on the next thread measured parallel to the axis.
b) The distance of the full length of the thread
c) The distance from the bottom of a head on a bolt to the first thread.
d) The distance from the top of one thread to the bottom of the next thread
73. Tapered shanks are used on large drill presses so that:
a) The drill can be centered more easily
b) The drill can be easily forced out of the sleeve with a drift
c) The shank will not turn when cutting
d) The shank can be ground when wrn
74. It is a type of chuck wherein a work piece with standard diameter or size could be attached fast and quick specially small size work of mass
production. How do you call this type of chuck?
a) Collet attachment
b) Lathe drive plate
c) Clamp toe dog
d) Steady center rest
75. A type of projection where the object is drawn as viewed in a glass box. Thus, the views are projected to six sides of the box.
a) Fourth angle projection
b) Third angle projection
c) Second angle projection
d) First angle projection
76. Which of the following is often called as the backbone of lathe machine?
a) Bed
b) Headstock
c) Tailstock
d) Carriage
77. Which of the following properties of metal is insensitive to the microstructure?
a) Hardness
b) Ductility
c) Tensile strength
d) Modulus of elasticity
78. Which of the following elastic modulus is applied to liquids?
a) Young’s Modulus
b) Bulk Modulus
c) Shear modulus
d) Modulus of rigidity
79. Polymers which, at room temperature, can undergo large deformations under a load and return back to their original shape upon release of load
called as:
a) Meso-polymers
b) Thermoplastics
c) Thermosetting polymers
d) Elastomers
80. When using a drill press, the work should be held with which of the following?
a) The hand
b) The glove hand
c) Pliers
d) A vise and clamp
81. Which of the following classes of materials exhibits a decreasing electrical conductivity with increasing temperature?
a) Intrinsic semiconductor
b) P-type semiconductor
c) Metals
d) Pure ionic materials
82. Which of the following is another name of hydrochloric acid?
a) Sulfuric acid
b) Acetic acid
c) Muriatic acid
d) Nitric acid
83. Fatigue failure occurs when a part is subjected to which of the following?
a) Fluctuating stress
b) Torsion
c) Tensile stress
d) Compressive stress
84. A body having identical properties all over is called as:
a) Elastic
b) Homogeneous
c) Ductile
d) Isentropic
85. If a material recovers its original dimensions when the load is removed, the material is said to be:
a) Annealed
b) Brittle
c) Elastic
d) Plastic
86. It is the behaviour of metals where in strength is increased and ductility is decreased on heating at a relatively low temperature after cold working.
a) Strain aging
b) Screw dislocation
c) Clustering
d) Twinning
87. A ductile fracture is characterized by which of the following?
a) Fragmentation into more than two pieces
b) Negligible deformation
c) Appreciable plastic deformation prior to propagation of crack
d) rapid rate for crank propagation
88. How do you call the ability of a material to absorb energy when deformed elastically and to return it when unloaded?
a) Resilience
b) Hardness
c) Fatigue strength
d) Creep
89. The machinability of steel can be increased by which of the following?
a) Sulphur and carbon
b) Phosphorous, lead, & sulphur
c) Sulphur, graphite and aluminium
d) Silicon and Sulphur
90. Which of the following is steel with 0.8 % carbon and 100 % pearlite?
a) Solidus
b) hyper-eutectoid
c) Eutectoid
d) Austenite
91. The maximum hardenability of any steel depends on which of the following?
a) Chemical composition
b) Carbon content
c) Grain size
d) Alloying element present
92. Hastalloy contains which of the following?
a) Nickel and molybdenum
b) Nickel and copper
c) Copper and aluminium
d) nickel and aluminum
93. Trimming is a process associated with which of the following?
a) Machining of metals
b) Press work
c) Electroplating
d) Forging
94. Addition of lead and bismuth to aluminium results in which of the following?
a) Improving machinability
b) One of the best known age and precipitation hardening system
c) Improvement of corrosion resistance
d) Improvement of casting characteristics
95. Which of the following does not pertain to joining of metals?
a) Welding
b) Soldering
c) Casting
d) Brazing
96. Endurance strength is nearly proportional to the ultimate strength but not with:
a) Yield strength
b) Design stress
c) Shear stress
d) b and c
97. If the velocity of a mass is the same all the time during which motion takes place is called:
a) Deceleration
b) Uniform motion
c) Acceleration
d) None of these
98. In involute teeth, the pressure angle is often defined as the angle between the line of action and the line of tangent to the pitch circle. It is termed
as:
a) Helix angle
b) Angle of recess
c) Angle of obliquity
d) Arc of action
99. The function of the clutch in the machine tools is:
a) Lowering the drive speed
b) To disconnect or connect the shaft at will the drive
c) Alignment of drive shaft
d) To insure that two shafts line up at high speed
100. Which of the following is not a heat treatment process?
a) Sintering
b) Annealing
c) Hardening
d) Tempering
101. An instrument used to analyse the compositions of metals:
a) Spectrometer
b) Radiometer
c) Profilometer
d) Ultimate analyser
102. Creep is the term used in referring to the:
a) Elongation before yield point
b) Maximum stress of brittle materials
c) Fatigue limit of ductile materials
d) Continuous increase in the strain, or deformation, of any material subjected to stress
103. The strength of non-ferrous alloys is maximum at room temperature while that of ferrous metal has a maximum strength at:
o
o
o
o
b) 450 F
c) 1200 F
d) 350 F
a) 400 F
104. Which of the following is not a kind of a cast iron?
a) Malleable iron
b) Head iron
c) Gray iron
d) White iron
105. The kind of center which is being attached and meshed to the tailstock spindle which is also static while the work is rotating is:
a) Dead center
b) Live center
c) Focal center
d) Work center
106. Which process does not belong to the group?
a) Resistance welding
b) Soldering
c) Hardening
d) Brazing
107. It is the maximum stress achieved in stress-strain diagram.
a) Yield Strength
b) Ultimate strength
c) Elastic strength
d) Shear strength
108. A support where one end is pinned and other is roller-supported.
a) Simply supported beam
b) Column
c) Compound supported beam
d) Simple beam
109. Functions used to evaluate shear and moment diagrams, especially when discontinuities, such as concentrated load or moment, exist.
a) Singularity functions
b) Machine element functions
c) Finite element functions
d) Statistical Element functions
110. A condition where principal stresses exist while all other tensor elements are zero is known as:
a) Symmetrical tensor
b) Bolt tensor
c) Unsymmetrical tensor
d) Beam tensor
111. The stress at time of fracture or rupture is called as:
a) Ultimate stress
b) Fracture stress
c) Yield stress
d) Fatigue stress
112. It is the linear interpolation between densities of alloy concentration.
a) Rule of thumb
b) Miner’s rule
c) Rule of mixtures
d) Slide rule
113. Compounds of carbon and other elements forming long-chain molecules.
a) Polymers
b) Ceramics
c) Glasses
d) Isotropic
114. The stress above which stress is no longer linearly proportional to strain.
a) Proportional limit
b) Elastic limit
c) Ultimate limit
d) Yield limit
115. When a hot part is cooled suddenly by quenching, there is momentarily a high temperature gradient that induces a stress gradient. Some metal
parts under certain conditions crack as a result. How do you call this phenomenon?
a) Thermal-shock failure
b) Thermal fatigue
c) Honing
d) Quenching
116. It is the condition of a machine element when it is completely inoperable, cannot perform its intended function adequately, or is unreliable for
continued safe use. What do you call this condition?
a) Fail-safe condition
b) Failure condition
c) Critical condition
d) Salvage condition
117. 47. It is defined as the change in volume divided by the original volume.
a. linearly elastic
b. camber
c. dilatation
d. partially elastic
118. Material that can sustain elongation greater than 5% before fracture is called:
a) Brittle
b. ductile
c. deformable
119. The name given to a load whose value is constant over long time is:
a) Static load
b. Sustained load
120. The onset of plastic deformation is called:
a) Necking
b. yielding
d. rigid
c. Average load
d. Axial load
c. creeping
d. buckling
JCSF ENGINEERING REVIEW CENTER
MACHINE DESIGN/SHOP PRACTICE
# 2 Alvaran’s Apartment, Purok 7, Halang
City of Calamba, Laguna
MACHINE DESIGN AND SHOP PRACTICE
(Refreshers Trivia # 11)
Prepared by: Jose R. Francisco, PME
September 2012
MULTIPLE CHOICE QUESTIONS
Select the best answer from each of the following questions. On the answer sheet provided, shade the box that corresponds to your choice.
Strictly no erasures allowed.
1.
2.
This is a type of welding whereby a wire or powder from the nozzle of a spray gun is fused by a gas flame, arc or plasma jet and the molten
particles are projected in a form of spray by means of compressed air or gas. How do you call this type of welding?
a) Metal spray welding
b) Electro-slug welding
c) Electro-beam welding
d) plasma arc welding
Which of the following best describes the 0.2% offset yield stress?
a. It is the elastic limit after which a measurable plastic strain has occurred.
c. It is the stress at which the material elastically strains 0.2%.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
b. It is the stress at which the material plastically strains 0.2%.
d. It is 0.2% below the fracture point of the material
For shafts, the shear due to bending is a maximum at the neutral plane where the normal stress is
a. zero
b. minimum
c. maximum
d. constant
The bearing load on feather keys should not exceed
a. 600 psi
b. 800 psi
c. 1000 psi
d. 1200 psi
The screw thread commonly used for transmission of motion is one of the following types of ________ threads.
a. vee
b. knuckle
c. British Association
d. acme
Grey cast iron is best welded by
a. arc
b. oxy-acetylene
c. MIG
d. TIG
Which of the following does not belong to foundry or metal casting shop?
a) Core-making machine
b) Forging machine
c) Shake-out machine
Which of the following is an example of a solid lubricant?
a. graphite
b. molybdenum disulfide
c. tungsten disulfide
Speedometer drive is generally taken from
a. dynamo
b. flywheel
c. front wheel
In laminated spring the strips are provided in different lengths for
a. economy
b. reduction in weight
c. improved appearance
When a spring is made of ductile material, the curvature factor would be
a. zero
b. constant
c. unity
In motor vehicles, it is a very common practice to use a
a. multiple clutch
b. hydraulic clutch
c. cone clutch
Power brakes require ______ power.
a. equal
b. less
c. more
d) Molding machine
d. all of the above
d. gear
d. space consideration
d. positive
d. single plate clutch
d. pulsating
14. In practice it is found that arcs less than _______ require high belt tensions.
a. 135°
b. 150°
c. 165°
d. 180°
15. Which of the following is a suitable method to check the eccentricity of a shaft?
a) Bench target and scriber
b) Bench top and tachometer c) Bench side and calliper d) Bench centers and dial indicator
16. This is a work supporting device which is bolted to the saddle of the lathe machine. It travels with the cutting tool, and used to prevent the
springing away of the work piece from cutting tool. How do you call this part?
a) Tool post
b) Carriage stop
c) Follower rest
d) Rubber-flex collets
17. For maximum quietness, use sprockets with ______ or more teeth.
a. 21
b. 23
c. 25
d. 27
18. The curve that satisfy the law of gearing
a. tooth profile
b. stub curve
c. conjugate curve
d. involute curve
19. Which of the following raw materials are used in the foundry molding operation?
a) Silica sand, linseed oil, & flour
c) Silica sand, lime, flour
b) Silica sand, paste, & graphite electrode
d) Silica sand, bentonite, flour/paste, and water
20. Which of the following is not part of a micrometer calliper?
a) Head screw
b) Thimble
c) Spindle
d) Anvil
21. The flux that should be avoided in soldering electrical connection or commutator wires as it tends to corrode the connections.
a) Acid fluxes
b) Salt ammoniac
c) Zinc chloride
d) Sodium chloride
22. It is a lathe machine operation used to produce a flat surface at the end of the part such as parts that are attached to other components, or to
produce grooves for o-ring seats.
a) Boring
b) Knurling
c) Facing
d) Parting
23. A line drawn through all the points at which the teeth touch each other.
a. arc of contact
b. arc of approach
c. path of contact
d. angle of contact
1
MACHINE DESIGN/SHOP PRACTICE
24. The reason for noise at the time of engaging brakes.
a. back plate being loose or bent
b. brake shoe being loose or bent
c. brake drum could be defective
d. all of the above
25. Tumbling is done so as to
a. clean the surface of small parts
b. get surface finish
c. stress relieve the components
d. plate the surface
26. Which gauge is used to check internal threads?
a. plug gauge
b. ring gauge
c. thread plug gauge
d. thread ring gauge
27. A hacksaw blade can be placed in a frame in
a.. one position
b. two positions
c. three positions
d. four positions
28. When outside diameter of a job is turned in relation to the internal hole, the job should be held:
a. in three jaw chuck
b. on lathe mandrel
c. on face plate
d. between centers
29. These are molds prepared in the floor in the foundry which are very large and symmetrical objects can be mold.
a. drawbacks
b. sweep boards
c. drag
d. cupola
30. A caliper usually used to locate approximate centers of work.
a. hermaphrodite caliper b. vernier caliper
c. divider
d. micrometer
31. The most important operations in manufacturing is hole making. This can be done by which of the following?
a) Drilling machine
b) Sawing machine
c) Boring mills
d) Milling machine
32. It is a machine operation used to produce regularly shaped, roughness on cylindrical surfaces, as in making knobs. How do you call this
operation?
a) Milling
b) Sawing
c) Drilling
d) Knurling
33. Which of the following material properties is adversely affected by grain refinement?
a) Creep resistance
b) Tensile strength
c) Ductility
d) yield strength
34. Hard solder is made of which of the following?
a) Tin and zinc
b) tin and copper
c) Copper and zinc
d) Tin and lead
35. Which of the following is the unit of mass moment of inertia?
b) kg/m2
c) kg
d) N-m
a) kg-m2
36. Which of the following is the unit of Young’s modulus of elasticity?
a) Dimensionless
b) Pascal
c) Metter
d) Newton
37. When a lathe tool bit burns, it means that the:
a) Speed is too low
b) Material is too hard
c) Speed is too fast
d) Material can’t be cut
38. In Indian Standard System, it is a fit which has a close contact providing either a clearance or an interference. The tolerance zone of the hole
and shaft overlap.
a. interference fit
b. clearance fit
c. transition fit
d. shrink fit
39. A twist drill has its point thinned in order to ____________.
a. reduce the hole diameter
40. In a planer, the feed is provided
a. at forward stroke
b. increase the rake angle
c. locate the center punch mark
d. reduce the axial feed pressure
b. at return stroke
c. in between forward stroke
d. in between return stroke
41. The area of the machine shop whose metal is being melted to form a new shape.
a) Foundry area
b) Tool and die
c) Welding area
d) Mass production area
42. A corrosion occurs within or adjacent to a crevice formed by contact with another piece of the same or another metal.
a) Pitting
b) Galvanic
c) Erosion
d) Crevice
43. Which of the following is not part of a headstock?
a) Anvil
b) Spindle
c) Motor
d) Back gear
44. What kind of bond is commonly used?
a. vitrified
b. silicon
c. shellac
d. rubber
45. It is used on soft metals and non-metals for making holes.
a. center punch
b. dot punch
c. hollow punch
d. prick punch
46. Slightly rounding a cutting edge to reduce the probability of edge chipping is
a. broaching
b. butting
c. blunting
d. bleaching
47. The length of shaper stroke is the length of job plus ________.
a. displacement
b. tolerance
c. allowance
d. clearance
48. Which of the following pairs of plastics and their modes of formation are correctly matched?
1. Polythene ------------------------- Condensation polymerization
2. Polycarbonate ------------------- Addition polymerization
3. Polystyrene ----------------------- Addition polymerization
4. Polyamide ------------------------- Either by addition or by condensation polymerization
Select the correct answer using the codes given below:
a. 3 and 4
b. 1 and 4
c. 1 and 2
d. 2 and 4
49. Dielectric strength of a material depends on the material’s __________.
a. moisture content
b. thickness
c. temperature
d. all of the above
50. Which of the following is a primary cell?
a. mercury-oxide
b. lead-acid
c. nickel-iron-alkaline
d. nickel-cadmium-alkaline
51. It refers to any layer or deposit of extraneous material on a heat-transfer surface.
a) Low line
b) Pressure drop
c) Fouling
d) Scaling
52. Have the same thermal and minimum film thickness limitation as sleeve bearing.
a) Ball bearing
b) Roller bearing
c) Thrust bearing
d) Oil whip
2
MACHINE DESIGN/SHOP PRACTICE
53. An oil storage tank roof formed to approximately a spherical surface, supported only at its periphery.
a) Self-supporting umbrella roof
54. What is a unit deformation?
a) Torsion
55. Accident prevention is:
b) Self-supporting cone roof
c) Self-supporting
d) Supported cone roof
b) Strain
c) Stress
d) Shear
a) An association of employers, organization & individuals
c) The Foreman’s responsibility just as much as production
b) A job of a safety director
d) The responsibility of top management
56. Fixture clamps are generally made of
a. high carbon steel
b. high speed steel
c. case-hardened mild steel
57. Steel can be strengthened by all of the following practices EXCEPT
a. annealing
b. work hardening
c. quenching and tempering
58. Which of the following metals has the highest specific heat capacity at 100°C?
a. aluminum
b. bismuth
c. copper
d. alloy steel
d. grain refinement
d. iron
59. Alloy steel known for its resistance to corrosion, abrasion and wear that is usually ideal for mill grinding of ore in cement and concentrator
application. It is usually combined with molybdenum to increase the depth hardening.
a) Manganese chromium steel
b) Chromium-moly steel
c) Chrome-nickel-moly steel
d) Manganese-moly steel
60. Cutting of internal threads of a work piece can be produced by which of the following?
a) Milling
b) Tapping
c) Boring
d) Reaming
61. Which of the following milling operations is used to produce curved profiles, with cutters that have specially shaped teeth?
a) Form
b) Straddle
c) End
d) Slab
62. In screw threads, what is a pitch?
a) The distance from a point on one thread to a corresponding point on the next thread measured parallel to the axis.
b) The distance of the full length of the thread
c) The distance from the bottom of a head on a bolt to the first thread.
d) The distance from the top of one thread to the bottom of the next thread
63. Tapered shanks are used on large drill presses so that:
a) The drill can be centered more easily
c) The shank will not turn when cutting
b) The drill can be easily forced out of the sleeve with a drift
d) The shank can be ground when worn
64. What is used in the main condenser to control electrolysis?
a. brass plates
b. aluminum plates
c. zinc plates
d. bronze plates
65. An intimate mechanical mixture of two or more phases having a definite composition and a definite freezing or melting point.
a. allotropy
b. peritectic
c. eutectic
d. pearlitic
66. The cylinder head of a steam engine is held by 14 bolts. The diameter of the cylinder 14 inches and the steam pressure is 125 psi. What size
of bolts is required if tensile stress is 3000 psi?
a. use 1-in bolt nominal diameter
b. use 1/2-in bolt nominal diameter
c. use 3/4-in bolt nominal diameter
d. use 1 1/2-in bolt nominal diameter
67. It is a squeezing process used to finish steel or bar stock for special purposes.
a. cold forging
b. sizing
c. cold rolling
d. coining
68. Is a trade name for a patented alloy made up chiefly of cobalt, chromium, and tungsten in varying proportions.
a. stellite
b. carboloy
c. HSS
d. stainless steel
69. You can distinguish between carbon steel and high speed steel by ________ test.
a. punch
b. break
c. drop
d. spark
70. Usual allowance on raw steel materials for machining is about
a. 1/16 to ¼ inch
b. ½ to 1 inch
c. 1 to 1 ½ inch
d. 1 inch minimum.
71. It is a type of chuck wherein a work piece with standard diameter or size could be attached fast and quick specially small size work of mass
production. How do you call this type of chuck?
a) Collet attachment
b) Lathe drive plate
c) Clamp toe dog
d) Steady center rest
72. A type of projection where the object is drawn as viewed in a glass box. Thus, the views are projected to six sides of the box.
a) Fourth angle projection
b) Third angle projection c) Second angle projection d) First angle projection
73. Which of the following is often called as the backbone of lathe machine?
a) Bed
b) Headstock
c) Tailstock
d) Carriage
74. Which of the following properties of metal is insensitive to the microstructure?
a) Hardness
b) Ductility
c) Tensile strength
d) Modulus of elasticity
75. Which of the following is not considered as an NDT (Non-Destructive Testing) Method?
a. Leak Test
b. Hydrostatic Test
c. Eddy Current Test
d. Penetrant Test
76. The mechanical treatments by which the concentration of ores is increased are
a. Gravity Separation
b. Ore Dressing
c. Distillation
d. Sintering
77. In pure torsion, the minimum torsional stress occurs at the
a. long side
b. center
c. medium side
d. short side
78. Which of the following elastic modulus is applied to liquids?
a) Young’s Modulus
b) Bulk Modulus
c) Shear modulus
d) Modulus of rigidity
79. Polymers which, at room temperature, can undergo large deformations under a load and return back to their original shape upon release of
load called as:
a) Meso-polymers
b) Thermoplastics
c) Thermosetting polymers d) Elastomers
80. When using a drill press, the work should be held with which of the following?
a) The hand
b) The glove hand
c) Pliers
d) A vise and clamp
3
MACHINE DESIGN/SHOP PRACTICE
81. Which of the following classes of materials exhibits a decreasing electrical conductivity with increasing temperature?
a) Intrinsic semiconductor
b) P-type semiconductor
c) Metals
d) Pure ionic materials
82. When varying loads are applied that are not regular in amplitude, the loading is called
a. reversed loading
b. random loading
c. fluctuating loading
d. repeated loading
83. A built-in or fixed support is capable of supporting
a. an axial load
b. a bending moment
c. a transverse force
d. all of these
84. The coefficient of thermal expansion of concrete is almost equal to
a. plastic
b. steel
c. copper
d. wood
85. Which type of load is applied slowly and is never removed?
a. equilibrium load
b. impact load
c. uniform load
d. static load
86. In the overdrive transmission system, the rotation speed of _________ rests higher than that of engine’s speed.
a. main shaft
b. crankshaft
c. machine shaft
d. propeller shaft
87. In the top gear, the rotational speeds of ________ remain the same.
a. primary and lay shafts
b. main and lay shafts
c. secondary and main shafts
88. Which of the following is another name of hydrochloric acid?
a) Sulfuric acid
b) Acetic acid
c) Muriatic acid
89. Fatigue failure occurs when a part is subjected to which of the following?
a) Fluctuating stress
b) Torsion
c) Tensile stress
90. A body having identical properties all over is called as:
a) Elastic
b) Homogeneous
c) Ductile
91. If a material recovers its original dimensions when the load is removed, the material is said to be:
a) Annealed
b) Brittle
c) Elastic
92. The primary and lay shafts rotate in _______ direction.
a. different
b. reverse
c. the same
93. In many cases, the __________ of the shaft is an important design feature.
a. strength
b. rigidity
c. size
d. primary and main shafts
d) Nitric acid
d) Compressive stress
d) Isentropic
d) Plastic
d. none of the above
d. deflections
94. It is the behaviour of metals where in strength is increased and ductility is decreased on heating at a relatively low temperature after cold
working.
a) Strain aging
b) Screw dislocation
c) Clustering
d) Twinning
95. A ductile fracture is characterized by which of the following?
a) Fragmentation into more than two pieces
b) Negligible deformation
c) Appreciable plastic deformation prior to propagation of crack
d) rapid rate for crank propagation
96. How do you call the ability of a material to absorb energy when deformed elastically and to return it when unloaded?
a) Resilience
b) Hardness
c) Fatigue strength
d) Creep
97. The machinability of steel can be increased by which of the following?
a) Sulphur and carbon b) Phosphorous, lead, & sulphur
c) Sulphur, graphite and aluminium
d) Silicon and Sulphur
98. Cold drawing produces a ________ shaft than hot rolling, but with higher residual stresses.
a. stronger
b. weaker
c. harder
d. none of the above
99. For three keys, a _______ percent overload is often used.
a. 10
b. 15
c. 20
d. 25
100. The maximum hardenability of any steel depends on which of the following?
a) Chemical composition
b) Carbon content
c) Grain size
d) Alloying element present
Note: The following questions are for your reading and Familiarization
101. Hastalloy contains which of the following?
a) Nickel and molybdenum
b) Nickel and copper
c) Copper and aluminium
102. Trimming is a process associated with which of the following?
a) Machining of metals
b) Press work
c) Electroplating
d) nickel and aluminum
d) Forging
103. Addition of lead and bismuth to aluminium results in which of the following?
a) Improving machinability
b) One of the best known age and precipitation hardening system
c) Improvement of corrosion resistance
d) Improvement of casting characteristics
104. Which of the following does not pertain to joining of metals?
a) Welding
b) Soldering
c) Casting
d) Brazing
105. Endurance strength is nearly proportional to the ultimate strength but not with:
a) Yield strength
b) Design stress
c) Shear stress
d) b and c
106. If the velocity of a mass is the same all the time during which motion takes place is called:
a) Deceleration
b) Uniform motion
c) Acceleration
d) None of these
107. In involute teeth, the pressure angle is often defined as the angle between the line of action and the line of tangent to the pitch circle. It is
termed as:
a) Helix angle
b) Angle of recess
c) Angle of obliquity
d) Arc of action
108. The function of the clutch in the machine tools is:
a) Lowering the drive speed
b) To disconnect or connect the shaft at will the drive
c) Alignment of drive shaft
d) To insure that two shafts line up at high speed
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MACHINE DESIGN/SHOP PRACTICE
109. Which of the following is not a heat treatment process?
a) Sintering
b) Annealing
110. An instrument used to analyse the compositions of metals:
a) Spectrometer
b) Radiometer
111. Creep is the term used in referring to the:
a) Elongation before yield point
c) Fatigue limit of ductile materials
c) Hardening
d) Tempering
c) Profilometer
d) Ultimate analyser
b) Maximum stress of brittle materials
d) Continuous increase in the strain, or deformation, of any material subjected to stress
112. The strength of non-ferrous alloys is maximum at room temperature while that of ferrous metal has a maximum strength at:
a) 400 oF
b) 450 oF
c) 1200 oF
d) 350 oF
113. Which of the following is not a kind of a cast iron?
a) Malleable iron
b) Head iron
c) Gray iron
d) White iron
114. The kind of center which is being attached and meshed to the tailstock spindle which is also static while the work is rotating is:
a) Dead center
b) Live center
c) Focal center
d) Work center
115. Which process does not belong to the group?
a) Resistance welding
b) Soldering
c) Hardening
d) Brazing
116. It is the maximum stress achieved in stress-strain diagram.
a) Yield Strength
b) Ultimate strength
c) Elastic strength
d) Shear strength
117. A support where one end is pinned and other is roller-supported.
a) Simply supported beam
b) Column
c) Compound supported beam
d) Simple beam
118. Functions used to evaluate shear and moment diagrams, especially when discontinuities, such as concentrated load or moment, exist.
a) Singularity functions
b) Machine element functions
c) Finite element functions d) Statistical Element functions
119. A condition where principal stresses exist while all other tensor elements are zero is known as:
a) Symmetrical tensor
b) Bolt tensor
c) Unsymmetrical tensor
d) Beam tensor
120. The stress at time of fracture or rupture is called as:
a) Ultimate stress
b) Fracture stress
c) Yield stress
d) Fatigue stress
121. It is the linear interpolation between densities of alloy concentration.
a) Rule of thumb
b) Miner’s rule
c) Rule of mixtures
d) Slide rule
122. Compounds of carbon and other elements forming long-chain molecules.
a) Polymers
b) Ceramics
c) Glasses
d) Isotropic
123. The stress above which stress is no longer linearly proportional to strain.
a) Proportional limit
b) Elastic limit
c) Ultimate limit
d) Yield limit
124. When a hot part is cooled suddenly by quenching, there is momentarily a high temperature gradient that induces a stress gradient. Some
metal parts under certain conditions crack as a result. How do you call this phenomenon?
a) Thermal-shock failure
b) Thermal fatigue c) Honing
d) Quenching
125. It is the condition of a machine element when it is completely inoperable, cannot perform its intended function adequately, or is unreliable
for continued safe use. What do you call this condition?
a) Fail-safe condition
b) Failure condition
c) Critical condition
d) Salvage condition
126. How do you call a statistical data used to identify the most likely failure modes?
a) Finite element analysis
b) Fault free analysis
c) Failure analysis
d) Random analysis
127. It is a computational method used for solving complex shapes, such as those found in machinery; replaces the complex shape with a set of
simple elements interconnected at a finite set of a specific purpose. What is this computational method?
a) Finite element analysis
b) Numerical method of analysis
c) Fault free analysis
d) Synthesis
128. It is a design approach where needed service is made apparent before catastrophic failure. How do you call this?
a) Manifest danger design approach
b) Machine element function approach
c) Failure analysis
d) Random analysis
129. It is a beam where one end is fixed and other end is free. How do you call this beam?
a) Cantilever beam
b) Continues beam
c) Overhanging beam
d) Long beam
130. It is a method used to graphically visualize state of stress acting in different planes passing through a given point. What is this?
a) Mohr’s circle
b) Soderberg Criterion
c) Goodmann’s method
d) Gerber’s line criterion
131. This minimum distance is measured between the non-driving side of a tooth and the adjacent side of the mating tooth. It is the amount by
which the width of a tooth space exceeds the thickness of the engaging tooth measured on the pitch circle. What is this distance?
a) Circular pitch
b) Whole depth
c) Backlash
d) Space width
132. It is an arc of the pitch circle of a spur gear through which a tooth travels from the point of contact with the mating tooth to the pitch point.
What is this arc?
a) Arc of action
b) Arc of approach
c) Arc of recess
d) Involute curve
133. What is the intersection of the elements making up the pitch cone?
a) Pitch cone
b) Cone distance
c) Apex of pitch cone
d) Root cone
134. What do you call a type of bolt threaded on both ends and can be used where a through bolt is impossible?
a) Coupling bolt
b) Machine bolt
c) Stud bolt
d) Carriage bolt
135. To avoid excessive wear rate, what is the recommended limiting pressure for 6 x 19 rope for cast iron?
a) 200 psi
b) 400 psi
c) 300 psi
d) 500 psi
136. How do you call a type of welding where the arc is covered with a welding composition and a bare electrode wire is fed automatically?
a) Resistance welding
b) Submerged arc welding c) Induction welding
d) Spot welding
137. It is a kind of wear that occurs because of fatigue failure of the surface materials as a result of high contact stresses. What do you call this?
a) Slotting
b) Pitting
c) Involuting
d) Curving
138. It is caused by foreign matters, such as grit or metal particles, or by a failure of the oil film at low speed. How do yopu call this?
a) Auction
b) Scoring
c) Abrasion
d) Corrosion
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MACHINE DESIGN/SHOP PRACTICE
139. It occurs when the oil films fails, but in this case, the load and speed are so high that the metal is melted and the metal is smeared down the
profile. What is this?
a) Abrasion
b) Corrosion
c) Spalling
d) Scoring
140. In gearing system, it is the advance of the tooth in the face width divided by circular pitch. What do you call this?
a) Face contact ratio
b) Speed ratio
c) Profile ratio
d) Advance ratio
141. When the pitch line speed is above 8000 fpm, the teeth should be _____.
a) Ground after hardening
b) Should be cooled in air
c) Should not be quenched after hardening`
d) none of these
142. How do you call a spring material that is hard drawn (80 % reduction) but made up of high-grade steel?
a) Music wire
b) Oil tempered wire
c) Song wire
d) Chromium-silicon wire
143. The combination of applied normal and shear stresses that produces maximum principal normal stress or minimum principal normal stress,
with a third principal stress between or equivalent to the extremes.
a) Principal shear stress b) Principal normal stress
c) Maximum shear stress
d) Bending and shear stresses
144. It is a load applied transversely to longitudinal axis of member.
a) Combined loads
b) Concentrated load
c) Bending load
d) Distributed load
145. It is the intensity and direction of internal force acting at given point on particular plane.
a) Load
b) Strain
c) Stress
d) Sustained load
146. It is the capacity of a material to absorb energy when it is deformed elastically and then, upon unloading, to increase this energy.
a) Resilience
b) Toughness
c) Rigidity
d) Ductility
147. It is the strain energy per unit volume required to stress a material from an unloaded state to the point of yielding.
a) Modulus of roughness b) Modulus of elasticity
c) Modulus of rigidity
d) Modulus of resilience
148. The ability of the material to absorb energy up to fracture.
a) Toughness
b) Rigidity
c) Resilience
d) Stiffness
149. The Maximum-Shear-Stress Theory, as a failure prediction theory, is also known as:
a) von Mises criterion
b) Tresca yield criterion
c) Coulomb-Mohr theory d) Modified Mohr theory
150. A failure prediction theory, which states that a part subjected to any combination of loads will fail (by yielding or fracturing) whenever the
maximum shear stress exceeds a critical value.
a) Distortion-energy theory
b) Maximum-shear-stress theory
c) Internal friction theory
d) Modified Mohr theory
151. A theory in cyclic and impact loading, which states that damage at any stress level is proportional to number of cycles.
a) Miner’s Rule
b) Paris Power Law
c) Goodman Rule
d) Manson-Coffin Relationship
152. A journal bearing where the radius of the journal is less than the radius of the bushing or bearing.
a) Fitted journal bearing
b) Clearance journal bearing
c) Partial journal bearing
d) Full journal bearing
153. A lubrication where the load-carrying surfaces of the bearing are separated by a relatively thick film of lubricant, so as to prevent metal-tometal contact; and where the stability of the film can be explained by the laws of fluid mechanics.
a) Hydrostatic lubrication
b) Hydrodynamic lubrication c) Elastohydrodynamic lubrication
d) Boundary lubrication
154. A lubrication condition where non-conformal surfaces are completely separated by lubricant film and no asperities are in contact.
a) Elastohydrodynamic lubrication b) Boundary lubrication
c) Hydrodynamic lubrication
d) Hydrostatic lubrication
155. A speed at which rotating shaft becomes dynamically unstable.
a) Normal speed
b) Variable speed
c) Critical speed
d) Average speed
156. A ball bearing with race containing pronounced groove for rolling elements.
a) Crown bearing
b) Conrad bearing
c) Angular-contact bearing
d) Cylindrical bearing
157. A machining process for producing internal straight cylindrical surface or profiles, with process characteristics and tooling similar to those
for turning operations.
a) Boring
b) Drilling
c) Reaming
d) Milling
158. A machining operation for all types of metallic and nonmetallic materials and is capable of producing circular parts with straight or various
profiles.
a) Boring
b) Turning
c) Drilling
d) Milling
159. A set of specification for parts, materials, or processes intended to achieve uniformity, efficiency, and a specified quality.
a) Code
b) Standard
c) Law
d) Theorem
160. A set of specifications for the analysis, design, manufacture, and construction of something; the purpose of which is to achieve a specified
degree of safety, efficiency, and performance or quality.
a) Code
b) Standard
c) Law
d) Theorem
161. The algebraic difference between the maximum limit and the corresponding basic size.
a) Fundamental deviation
b) Upper deviation
c) Lower deviation d) Tolerance
162. A material having different properties in all directions at point in solid.
a) Isotropic material
b) Anisotropic material
c) Orthotropic material
d) Ceramic material
163. A principle or method that a deflection at any point in bar is equal to sum of deflections caused by each load acting separately.
a) Summation Method
b) Method of balancing
c) Method of superposition
d) Shear and Moment diagram method
164. A failure prediction theory in which failure is caused by the elastic energy associated with shear deformation.
a) Maximum-shear-stress theory
b) Distortion-energy theory
165. When a lathe tool bit is burns, it means that the:
a) Speed is too low
b) Material is too hard
166. What does the designation AISI 4130 for a steel mean?
a) Molybdenum-Chromium, 0.3 % carbon
c) Maximum-normal-stress theory
c) Speed is too fast
b) Plain carbon, 0.41 % carbon
d) Internal friction theory
d) Material cannot be cut
c) Molybdenum-nickel, 0.0 % carbon
d) Manganese, 0.13 % carbon
167. Which of the following is not a method of non-destructive testing of steel, casting and forging?
a) Radiography
b) Ultra sound
c) Magnetic particles
d) Chemical analysis
168. It is a spring wire with good quality for impact loads and moderately high temperatures. What is this spring material?
6
MACHINE DESIGN/SHOP PRACTICE
a) Hard drawn spring wire
b) helical spring wire
c) Chromium-silicon
d) Helical tension wire
169. What do you call a ratio of the length of the column and the radius of gyration of the cross-sectional area about the centroidal axis?
a) Power factor
b) Contact ratio
d) Constant ratio
d) Slenderness ratio
170. A screw that requires a positive torque to lower the load, or to loosen the screw if it has been turned tight against a resistance. How do you
call this screw.
a) Power screw
b) Self screw
c) Lock screw
d) Self-locking screw
171. How do you call the product of the length and diameter of the bearing?
a) Projected area
b) Shearing area
c) Compressive area
d) Cross-sectional area
172. Devise used to measure an accurate speed:
a) Speedometer
b) Dial Indicator
c) Tachometer
d) Dial Gauge
173. When the hole is smaller than shaft, it will take pressure to put the parts together. The allowance is said to be negative and is termed as:
a) Negative tolerance
b) Negative allowance
c) Negative fits
d) Interference of metal
174. When two elastic bodies collide, which of the following laws can be used to solve for the resulting velocity?
a) Dalton’s law
b) Avogadro’s law
c) Conservation of energy
d) Conservation of momentum and conservation of energy
175. The ability of a metal to be deformed considerably without rapture is called as:
a) Plasticity
b) Ductility
c) Malleability
d) All of these
176. Permanent deformation or strain may occur without fracture:
a) Malleability
b) Elasticity
c) Ductility
d) Plasticity
177. A mechanism that usually do the indexing in a machine tool:
a) Universal chuck
b) Slotter
c) Dividing head
d) Indexing
178. The product of the resultant of all forces acting on a body and the time that the resultant acts:
a) Angular impulse
b) Angular momentum
c) Linear Impulse d) Linear momentum
179. Which of the following is not a structural class of steel?
a) Low carbon steel
b) Tool and die steel
c) High chrome alloy steel d) High strength low allow steel
180. Poisson’s ratio is the ratio of which of the following?
a) Shear strain to compressive strain
c) Lateral strain to longitudinal strain
b) Elastic limit to compressive strain
d) Elastic limit to proportional limit
181. All are associated with the grade of steel except:
a) SAE 43xx
b) SAE 13xx
c) SAE 10xx
d) SAE 74xx
182. A property of material that relates the lateral strain to the longitudinal strain:
a) Stress
b) Strain
c) Poisson’s ratio d) Strength
183. The maximum stress to which a material may be subjected before failure occurs.
a) Ultimate strength
b) Ultimate stress
c) Endurance limit
d) Tensile stress
184. Hypoid gear is a special type of gear like:
a) Worm gear
b) Spur gear
c) Herringbone gear
d) Bevel gear
185. The considered maximum safe center distance of sprockets because very long center distance causes catenary tension in the chain.
a) 70 pitches
b) 80 pitches
c) 60 pitches
d) 50 pitches
186. Cold working of steel plates make the metal:
a) Tougher
b) More ductile
c) Harder
d) More malleable
187. Recommended best cutting angle of drill for work on steel or cast iron is:
a) 48 degree
b) 63 degrees
c) 59 degrees
d) 50 degrees
188. One of the causes of spur gear tooth breakage is the unbalanced load on one end of the tooth that results in higher stresses than when the
load is evenly distributed. To minimize this problem, the face width “b” should not be greater than the thickness (or pitch) of the tooth. In
the absence of test values, the following can be a guide:
b) 2pd < b < 4 pd
c) 2.5pd < b < 4pd
d) 2pc < b < 4 pc
a) 2.5pc < b 4pc
189. The three moment equation may be used to analyse:
a) Tapered column
b) Continuous beam
c) Composite beam
d) Axially end loaded beam
190. Ordinary steel begins to loose strength and elasticity significantly at about:
a) 900 to 1000 oF
b) 800 to 900 oF
c) 750 to 850 oF
d) 600 to 700 oF
191. Clearance to a new boiler installation to the existing or old plant building should follow a minimum clearance of ________ between top of
the boiler proper and the ceiling as stated in the PSME Code.
a) 2000 mm (max)
b) 1000 mm (max)
c) 2130 mm (max)
d) 2150 mm (max)
192. For a high corrosion resistant stainless steel, what minimum chromium content is required?
a) 8 %
b) 4.3 %
c) 1.1 %
d) 5.8 %
193. Name the type of chuck commonly used for holding workpiece in a lathe operation. Example: 3-jaw universal chuck, 4-jaw independent
chuck.
a) Magnetic jaw chuck b) 2-jaw independent chuck
c) 8-jaw universal
d) Combination
194. V-belt operate efficiently at speed of about:
a) 4500 fpm
b) 4400 fpm
c) 4200 fpm
d) 3600 fpm
195. What type of gear is used for high speed operation?
a) Helical
b) Spur
c) Bevel
d) Worm
196. In a pair of gears, it is the plane perpendicular to the axial plane and tangent to the pitch surface.
a) Pitch
b) Pitch plane
c) Pitch circle
d) Pitch point
197. Killed steel is always associated with:
a) Silicon
b) Manganese
c) Phosphorous
d) Sulfur
198. The usual ratio of water to soluble oil used as cutting fluid.
a) 50 % water to 50 % oil
b) 2 water to 1 oil
c) 3 water to 1 oil
d) 4 to 80 water to 1 oil
7
MACHINE DESIGN/SHOP PRACTICE
199. How do you call a type of welding whereby a wire or powder from the nozzle of a spray gun is fused by a gas flame, arc or plasma jet and
the molden particles are projected in form of a spray by means of compressed air or gas?
a) Electro-slug building
b) Electro-beam welding
c) Plasma arc welding
d) Metal spray welding
200. Which of the following does not belong to foundry or metal casting shop?
a) Shake-out machine
b) Molding machine
c) Core making
d) Forging machine
201. Which of the following is an unsafe act or condition in operating a lathe machine?
a) Wearing demin pants and safety shoes
c) Operating with safety gloves
b) Wearing a canvas apron
d) Wearing safety goggles and hearing aid
202. It is a type of welding in which the weld metal is a mixture of aluminum powder and a metal oxide powder which is ignited in a crucible.
a) Thermit welding
b) Gas welding
c) Electric arc welding
d) Metal spray welding
203. These are polymers which, at room temperature, can undergo large deformation under a load and return back to their original shape upon
release of load.
a) Elastomers
b) Thermosetting polymers
c) Thermoplastics
d) Meso-polymers
204. Which of the following is the 4th most commonly used metal in the world?
a) Zinc
b) Steel
c) Aluminum
d) Copper
205. The most widely used material for machine elements because of its properties of high strength, high stiffness, durability, and relative ease of
fabrication.
a) Zinc
b) Steel
c) Aluminum
d) Copper
206. In a pressure vessel, the ratio of minimum strength of joint to the strength of solid joint is known as:
a) Efficiency
b) Performance Factor
c) Joint Efficiency d) Relative Strength
207. In a pressure vessel, the usual factor of safety may be taken as:
a) 2
b) 4
c) 3
d) 5
208. It is the permissible variation of the size of a dimension.
a) Tolerance
b) Fits
c) Limits
d) None of above
209. If there is no fit, a liberal tolerance of the order of ______ in machining work could be permitted.
a) ± 0.020
b) ± 0.010
c) ± 0.09
d) ± 0.05
210. A tolerance where the size of a part is permitted to be either larger or smaller than the given dimension.
a) Bilateral
b) Unilateral
c) lateral
d) None of these
211. A tolerance where the size of a part may be larger only, or smaller only, than the given dimension.
a) Bilateral
b) Unilateral
c) Lateral
d) None of these
212. If two principal stresses are zero, the state of stress is:
a) Biaxial
b) Uni-axial
c) Mono-axial
d) Triaxial
213. If one principal stress is zero, the state of stress is:
a) Biaxial
b) Uni-axial
c) Mono-axial
d) Triaxial
214. If all the principal stresses have finite values, the system is:
a) Biaxial
b) Uni-axial
c) Mono-axial
d) Triaxial
215. Under theories of failure, for static loading of ductile material, the design stress is equal to:
a) Yield stress/Factor of safety
b) Ultimate stress/Factor of safety
c) Factor of safety/Yield stress
d) Endurance strength/Factor of safety
216. An old rule of thumb for transmission shafting is that the deflection should not exceed _______ of length between supports.
a) 0.01 inch per foot
b) 0.03 inch per foot
c) 0.02 inch per foot
d) 0.04 inch per foot
217. In general, for machinery shafts, the permissible deflection may be closer to:
a) 0.02 inch per foot
b) 0.01 inch per foot
c) 0.002 inch per foot
d) 0.03 inch per foot
218. What is this part of headstock of a lathe machine used to transmit power from the spindle?
a) Motor
b) Back gear
c) Headstock spindle
d) Switch
219. When a hot part is cooled suddenly by quenching, there is momentarily a high temperature gradient that induces a stress gradient. Some
metal parts under certain conditions crack as a result. What is this phenomenon?
a) Thermal-shock failure
b) Thermal fatigue c) Honing
d) Quenching
220. How do you call an axial distance that a screw advances in one turn or revolution?
a) Lead
b) Circular pitch
c) Pitch
d) Axial pitch
221. What is a screw fastener with a nut on it?
a) Bolt
b) Rivet
c) Fastener
d) Square screw
222. It is a type of bolt distinguished by a short portion of shank underneath the head, being square or finned or ribbed. What is this bolt?
a) Coupling bolt
b) Machine bolt
c) Stud bolt
d) Carriage bolt
223. How do you call a large wood screw that is used to fasten machinery and equipment to a wooden base?
a) Lag screw
b) Wood screw
c) Log screw
d) Square screw
224. It is a low cost spring material, suitable where service is not severe and dimensional precision is not needed. How do you call this spring
material?
a) Hard drawn wire
b) helical spring wire
c) Stainless steel
d) helical tension spring wire
225. Used for permanent fits, are similar to involute splines except that the pressure angles 14.5o
a) Separation load
b) Stub serrations
c) Spline shaft
d) Involute serrations
226. Are used as couplings or in additions to other couplings where, in case of overload, there is a danger of injury to machines o to materials in
process.
a) Involute serrations
b) Shear pin
c) Flange coupling
d) King pin
227. A coupling that transmits power via the frictional forces induced by pulling the flanges each over slotted tapered sleeves.
a) Flange coupling
b) Ribbed compression coupling
c) Rigid Coupling
d) Flanged compression coupling
8
MACHINE DESIGN/SHOP PRACTICE
228. A coupling used for absorbing some shock and vibration that may appear on one shaft and preventing the occurrence of reversed
stresses caused of the shaft deflecting at the coupling.
a) Rigid Coupling
b) Flexible Coupling
c) Flange Coupling
d) None of these
229. For thrust bearings, the speed at the moderate operating condition is
b) 50 < Vm < 220 fpm
c) 50 < Vm< 250 fpm
d) 50 < Vm < 290 fpm
a) 50 < Vm < 200 fpm
230. Experience suggests that the most economical designs are obtained for a belt speed of
a) 4000 to 4500 fpm
b) 2000 to 3000 fpm
c) 3000 to 4000 fpm
d) 4000 to 5000 fpm
231. For leather belts, recommended speed is
a) 6000 to 7500 fpm
b) 2000 to 3000 fpm
c) 7000 to 8000 fpm
d) 4000 to 5000 fpm
232. The ability of the material to absorb energy up to fracture.
a) Toughness
b) Rigidity
c) Resilience
d) Stiffness
233. The combinations of two or more materials, usually consisting of fiber and thermosetting polymer.
a) Brittle materials
b) Composite materials
c) Polymers
d) Ceramics
234. The product of the length and diameter of the bearing is called:
a) Projected area
b) Shearing area
c) Compressive area
d) Cross-sectional area
235. In motor vehicles, it is a very common practice to use:
a) Multiple clutch
b) Hydraulic clutch
c) Cone clutch
d) Single plate clutch
236. Which gauge is used to check internal threads?
a) Plug gauge
b) Ring gauge
c) Thread plug gauge
d) Thread ring gauge
237. When outside diameter of a job is turned in relation to the internal hole, the job should be held:
a) In three-jaw chuck
b) On the lathe mandrel
c) On face plate
d) Between centers
238. Shaper operation which is shaping the given stock and having the excess material remain with a tolerable allowance for finishing.
a) Roughing
b) Finishing
c) Angular cutting
d) Contouring
239. The property of a material that measures the degree of plastic deformation sustained at fracture.
a) Toughness
b) Stiffness
c) Ductility
d) Brittleness
240. The product of the resultant of all forces acting on a body and the time that the resultant acts:
a) Angular impulse
b) Angular momentum
c) Linear Impulse
d) Linear momentum
241. Which of the following is not a structural class of steel?
a) Low carbon steel
b) Tool and die steel
c) High chrome alloy steel
d) High strength low allow steel
242. Poisson’s ratio is the ratio of which of the following?
a) Shear strain to compressive strain
c) Lateral strain to longitudinal strain
b) Elastic limit to compressive strain
d) Elastic limit to proportional limit
243. All are associated with the grade of steel except:
a) SAE 43xx
b) SAE 13xx
c) SAE 10xx
d) SAE 74xx
244. A property of material that relates the lateral strain to the longitudinal strain:
a) Stress
b) Strain
c) Poisson’s ratio
d) Strength
245. The phenomenon of continuous stretching under load even if the stress is less than the yield point.
a) Elasticity
b) Ductility
c) Plasticity
d) Creep
246. A machinery operation whereby done with the accurately fastened has a reciprocating (forward and backward) motion and tool head is
stationary.
a) Shaping
b) Planing
c) Turning
d) Reaming
247. The maximum stress to which a material may be subjected before failure occurs.
a) Ultimate strength
b) Ultimate stress
c) Endurance limit
d) Tensile stress
248. Hypoid gear is a special type of gear like:
a) Worm gear
b) Spur gear
c) Herringbone gear
d) Bevel gear
249. The usual ratio of water to soluble oil used as cutting fluid.
a) 50 % water to 50 % oil
b) 2 water to 1 oil
c) 3 water to 1 oil
d) 4 to 80 water to 1 oil
250. The considered maximum safe center distance of sprockets because very long center distance causes catenary tension in the chain.
a) 70 pitches
b) 80 pitches
c) 60 pitches
d) 50 pitches
9
MACHINE DESIGN/SHOP PRACTICE
JCSF ENGINEERING REVIEW CENTER
# 2 Alvaran’s Apartment, Purok 7, Halang
City of Calamba, Laguna
MACHINE DESIGN AND SHOP PRACTICE
(Refreshers Trivia # 12 for September 2012 Board Examination)
Prepared by: Jose R. Francisco, PME
September 2012
MULTIPLE CHOICE QUESTIONS
Select the best answer from each of the following questions. On the answer sheet provided, shade the box that corresponds to your choice. Strictly no
erasures allowed.
1. A motor is used to drive a centrifugal pump that discharges 3000 li/min at a head of 10m. The pump efficiency is 68% and running at 550 rpm. Find the
torsional stress of shaft if shaft diameter is 35mm.
A. 13.85 MPa
B. 11.85 MPa
C. 12.85 MPa
D. 14.87 MPa
Solution:
⎛ 3000 ⎞ 3
⎜
⎟m / s × 9.81kN / m3 × 10m
Q ⋅ γ ⋅ TDH ⎝ 60 × 1000 ⎠
P=
=
= 7.213kW = 7.213 × 106 N ⋅ mm / s
e
0.68
(
6
⎛
⎛ 30 ⋅ P ⎞ 16 × ⎜ 30 × 7.213 × 10
16 × ⎜
⎟
⎜
π × 550
16 ⋅ T
⎝ π⋅ N ⎠ =
⎝
=
Ss =
3
3
π⋅D
π⋅D
π × 353
2.
SR =
N motor
Nsawblade
V = π⋅D⋅ N = π×
; N sawblade =
3
800
1000
× 3.28ft / m = 137.39ft / sec
m×
1000
60 sec
⎛ 10 ⎞
D= ⎜
⎟ = 1.18in
⎝ 8.95 ⎠
2
Two circular shafts, one hollow shaft and one solid shaft, are made of the same material and have diameters as follow: hollow shaft inside diameter is
one-half of the external diameter. The external diameter is equal to the diameter of the solid shaft. What is the ratio of the twisting moment of the hollow
shaft to that of the solid shaft?
A.1/4
B. 1/3
C. 9/16
D. 15/16
(
)
32 ⋅ T ⋅ L
π⋅G
⎡
⎛D
θ S × D o4 = θ H × ⎢D o4 − ⎜⎜ o
⎢⎣
⎝ 2
15
θS = θ H
16
Do
and Ds = Do
2
But: Di =
⎞
⎟⎟
⎠
4⎤
⎛
D4 ⎞
θ S × D o4 = θ H × ⎜ D o4 − o ⎟
⎜
16 ⎟⎠
⎝
⎥
⎥⎦
θ S × D o4 = θ H ×
15D o4
16
Determine the thickness of the hollow shaft having an outside diameter of 100 mm If it is subjected to a maximum torque of 5,403.58 N.m without
exceeding a shearing stress of 60 MPa or a twist of 0.5 degree per meter length of shaft. G=83,000 MPa
A. 15 mm
B. 86 mm
C. 16.8 mm
D. 14.2 mm
Solution:
32 ⋅ T
θ
=
L π ⋅ D o4 − D i4 ⋅ G
(
)
0.5 o ×
π
(
)
3
180 o = 32 × 5403.58 × 10
1× 1000
π × 100 4 − D i4 × 83000
(
then; t =
6.
D. 1.64
3
Solution: θS ⋅ DS4 = θ H ⋅ D o4 − Di4 =
5.
1800
= 1000rpm
1.8
A shaft has a length of 10 ft. Find the diameter of the shaft that could safely deliver.
A. 1.18 in
B. 7.55 in
C. 2.34 in
Solution: L = 8.95 ⋅ D
4.
⎟
⎠ = 14.87 MPa
An 800 mm diameter circular saw blade is driven by a 1800 rpm motor with gear speed ratio of 1.8. Find the peripheral speed of the blade.
A. 137.39 ft/sec
B. 140.65 ft/sec
C. 132.43 ft/sec
D. 135.21 ft/sec
Solution
3.
)⎞⎟
)
D i = 70mm
D o − D i 100 − 70
=
= 15mm
2
2
A tubular shaft having, having an inner diameter of 30 mm and outside diameter of 42 mm, is to be used to transmit 90 kW power. Determine the
frequency of rotation of the shaft so that the shear stress cannot exceed 50 MPa.
A. 26.6 Hz
B. 20.6 Hz
C. 97.5 Hz
D. 66.5 Hz
1
MACHINE DESIGN/SHOP PRACTICE
Solution: T =
P
90 × 106 1432.3944 × 104
=
=
2π ⋅ N 2 ⋅ π ⋅ N
N
Then,
7.
(
1432.3944 × 104 50 × π × 424 − 304
=
N
16 × 42
)
(
)
Also, T =
S ⋅ π ⋅ Do4 − Di4
16D0
N = 26.6
rev
cycle
= 26.6
= 26.6Hz
s
sec
A solid transmission shaft is 3.5 inches in diameter. It is desired to replace it with a hollow shaft with the same material and same torsional strength but
its weight should only be half as much as the solid shaft. Find the outside diameter and the inside diameter of the shaft in millimeters.
A. 107.31 mm ; 86.97 mm
B. 112.231 mm ; 84.60 mm C. 120.217 mm; 65.97 mm
D. 131.204 mm ; 54.30 mm
Ds = 3.5in = 88.9mm
Solution: When solid shaft is to be replaced by hollow shaft having equal strength but 1/2 weight
⎞
⎛
⎛1+ 2 ⎞
⎟ ⋅ D = ⎜ 1 + 2 ⎟ × 88.9 = 107.31mm
Do = ⎜
⎜ 2 ⎟ s ⎜ 2 ⎟
⎠
⎠
⎝
⎝
8.
Ds2
88.92
= 107.312 −
= 86.97 mm
2
2
A turbine is connected to a generator by means of flange bolt coupling that has a bolt circle diameter of 500 mm. The generator output is 40 MW, 3600
rpm and 90% efficiency. If there are 16 bolts, determine the force acting on each bolt.
A. 26.41 kN
B. 29.47 kN
C. 35.62 kN
D. 32.61 kN
Solution: Pinput =
Poutput
e
Fb =
9.
Di = Do2 −
=
40
= 44.44MW
0.90
(
T=
)
(
)
30P
30 × 44.44 × 103
=
= 117.88kN.m
πN m
π × 3600
2T
2 × 117.88 × 103
=
= 29.47 kN
n bDb
16 × 500
A 75 mm diameter shaft is transmitting 300 kW at 600 rpm. As solid coupling has 6 bolts and each is 18 mm in diameter, find the required bolt circle
diameter if shearing stress in bolt is 27.5 MPa.
A. 227.4 mm
B. 233.6 mm
C. 254.5 mm
D. 272.6 mm
(
Solution: Ssb =
8T
π ⋅ n b ⋅ d 2 ⋅ Db
T=
and
)
⎡ 30 × 300 × 106 ⎤
⎛ 30P ⎞
8× ⎢
⎥
8⎜
⎟
π × 600
⎢⎣
⎦⎥ = 227.4mm
⎝ πN ⎠
Then, D b =
=
π × 6 × 182 × 27.5
π ⋅ n b ⋅ d 2 ⋅ Ssb
30P
πN
10. A flat key is to be designed for a 75 mm diameter shaft which will transmit 150 kW at 400 rpm. If allowable shearing stress is 20 MPa and key width is
15 mm, determine the length of the key.
A. 30.65 mm
B. 31.83 mm
C. 33.75 mm
D. 32.85 mm
(
6
⎡
⎛ 30P ⎞ 2 × ⎢ 30 × 150 × 10
2⎜
⎟
⎢⎣ π × 4000
2T
πN ⎠
Solution: L =
=
= ⎝
Sc ⋅ b ⋅ D Sc ⋅ b ⋅ D
20 × 75 × 15
)⎤⎥
⎥⎦
= 31.83mm
11. A square key is to be used in a 40 mm flat key and that will develop a 2 kN.m torque. If bearing stress of key is 448 MPa, determine the cross sectional
dimension of flat key to be used using key length of 21.12 mm.
A. 21.12 mm
B. 25.61 mm
C. 28.21 mm
D. 18.61 mm
Solution:
t=
(
)
4T
4 × 2 × 106
=
= 21.13mm
Sc ⋅ b ⋅ D 448 × 21.12 × 40
12. A rectangular key was used in a pulley connected to a line shaft with power of 7.46 kW at a speed of 1200 rpm. If the shearing stress for the shaft and
2
2
key are 30 N/mm and 40 N/mm , respectively. What is the diameter of the shaft?
A. 18.7 mm
B. 21.7 mm
C. 25.8 mm
D. 30.2 mm
Solution:
⎛ 30P ⎞
16⎜
⎟
16T
⎝ π⋅ N ⎠
S=
=
π ⋅ D3
π ⋅ D3
(
hence;
)
⎡ 30 × 7.46 × 106 ⎤
⎛ 30P ⎞
⎥
16⎜
⎟ 3 16 ⎢
π × 1200
3
⎣⎢
⎦⎥ = 21.6mm
⎝ π⋅ N ⎠ =
D=
π × 30
π ⋅S
13. A bearing 150 mm diameter and 300 mm long supports a load of 5000 kg. If coefficient of friction is 0.18, find the torque required to rotate the shaft.
A. 331 N-m
B. 662 N-m
C. 873 N-m
D. 1020 N-m
Solution: Ff = f ⋅ W = 0.18 × (5000 × 9.8066 ) = 8825.94 N
Tf = Ff ⋅
D
0.150
= 8825.94 ×
= 662 N.m
2
2
14. A bearing, whose shaft rotates at 500 rpm, has a friction loss of 15 kW. The bearing load is 30 kN and friction of 0.14. Find the bearing diameter.
A. 136.42 mm
B. 146.42 mm
C. 156.42 mm
D. 166.42 mm
2
MACHINE DESIGN/SHOP PRACTICE
D⎞
⎛
Pf = 2π ⋅ Tf ⋅ N = 2π ⋅ ⎜ Ff × ⎟ ⋅ N = π ⋅ Ff ⋅ D ⋅ N
2⎠
⎝
Pf
15
=
× 1000 = 136.42mm
Then, D =
π ⋅ Ff ⋅ N π × 4.2 × 500
60
Solution: Ff = f ⋅ W = 0.14 × 30 = 4.2kN
15. A shaft revolving at 1740 rpm is supported by bearing with a length of 105 mm and diameter of 64 mm. If the load is light and SAE Oil No. 20 ( µ = 2.4 x
-6
10 reyns ) is used and diametral clearance is 0.136 mm, find the power loss due to friction.
A. 164 watts
B. 174 watts
C. 184 watts
D. 194 watts
-6
Solution: µ = 2.4 x 10 reyns = 0.0165 Pa-s
h = Cd / 2 = 0.136/2 = 0.068 mm
3
1740
⎛ 0.064 ⎞
4 × π2 × ⎜
⎟ × 0.0165 × 0.105 ×
4 ⋅ π2 ⋅ r 3 ⋅ µ ⋅ L ⋅ Ns
2 ⎠
60
⎝
=
= 0.9558 N.m
Then, Tf =
h
0.068 × 10−3
1740
Pf = 2 ⋅ π ⋅ Tf ⋅ Ns = 2 × π × 0.9558 ×
= 174 watts
60
16. A bearing 2.085 inches in diameter and 1.762 in long supports a journal running at 1200 rpm. It operates satisfactorily with a diametral clearance of
0.0028 in and a total radial load of 1400 lbs. at 160° F operating temperature of the oil film, the bearing modulus Zn/P was found to be 16.48.
Determine the bearing stress.
A. 281 psi
B. 381 psi
C. 481 psi
D. 581 psi
Solution: Sb =
F
F
1400
=
=
= 381psi
A D × L 2.085 × 1.762
17. Find the tooth thickness of a 14° involute gear having a diametral pitch of 6.
A. 5.33 mm
B. 6.65 mm
C. 8.45 mm
Solution:
tooth thickness =
D. 12.36 mm
1.5708 1.5708
=
× 25.4 = 6.65mm
Pd
6
18. Compute for the speed mounted in a 52.5 mm diameter shaft receiving power from a prime motor with 250 Hp.
A. 2182 rpm
B. 2081 rpm
C. 2265 rpm
D. 2341 rpm
Solution:
P=
D3 × N
80
hence;
N=
80P
D3
=
80 × 250
⎛ 52.5 ⎞
⎜
⎟
⎝ 25.4 ⎠
3
= 2265rpm
19. A spur pinion rotates at 1800 rpm and transmits to mating gear 30 Hp. If the pitch diameter is 8 inches and the pressure angle is 14.5°, determine the
total loads in lbs.
A. 123.45 lbs
B. 653.15 lbs
C. 271.14 lbs
D. 327.43 lbs
Solution:
Then;
T=
63,000Hp 63,000 × 30
=
= 1050in.lb
Nm
1800
F=
Ft
262.5
=
= 271.14lbs
cos φ cos14.5
Ft =
2T 2 × 1050
=
= 262.5lbs
D
8
20. A precision cut gear transmits 25 Hp at a pitch line velocity of 6000 ft/min. If the service is intermittent, compute for the dynamic load.
A. 244 lb
B. 264 lb
C. 274 lb
D. 284 lb
Solution:
Ft =
Hp × 33000 25 × 33000
=
= 137.5lbs
Vm
6000
For precision cut;
⎡ 78 + Vm
Fd = ⎢
78
⎢⎣
⎤
⎡ 78 + 6000 ⎤
⎥ × Ft = ⎢
⎥ × 137.5 = 274lbs
78
⎥⎦
⎢⎣
⎦⎥
21. A 28-tooth helical gear having a pitch diameter of 7 has a helix angle of 22 degrees. Find the circular pitch in a plane normal to the pitch.
A. 0.528
B. 0.628
C. 0.728
D. 0.828
Solution:
⎛ πD ⎞
⎛ π×7 ⎞
Pcn = ⎜
⎟ × cos ψ = ⎜
⎟ × cos 22 = 0.728
⎝ T ⎠
⎝ 28 ⎠
22. A helical gear having 20 teeth and pitch diameter of 5 in. Find the normal diametral pitch if helix angle is 22 degrees.
A. 3.31 in
B. 4.31 in
C. 5.31 in
D. 6.31 in
Solution:
Pdn =
T
20
=
= 4.31 in
D × cos ψ 5 × cos 22
3
MACHINE DESIGN/SHOP PRACTICE
23. A helical gear tangential load of 200 lbs and axial load of 73 lbs. find the helix angle.
A. 14 degrees
B. 16 degrees
C. 18 degrees
Solution:
D. 20 degrees
⎡F ⎤
⎡ 73 ⎤
o
ψ = tan −1 ⎢ a ⎥ = tan −1 ⎢
⎥ = 20
⎣ 200 ⎦
⎣ Ft ⎦
24. A pair of straight bevel gear connects a pair of shafts 90°. The velocity ratio is 3 to 1. What is the cone pitch angle of smaller gear?
A. 71.57 deg
B. 65.34 deg
C. 18.43 deg
D. 12.34 deg
Solution:
SR =
Tg
Tp
=
3
1
tan α =
sin θ
Tg
Tp
For θ = 90°,
+ cos θ
⎡ Tp ⎤
⎡1⎤
α = tan −1 ⎢ ⎥ = tan −1 ⎢ ⎥ = 18.43 deg
T
⎣3⎦
⎣⎢ g ⎦⎥
25. A spiral bevel pinion with a left hand spiral rotates clockwise transmits power to a mating gear with speed ratio of 2 to 1. Determine the pitch angle of
the pinion.
A. 16.56 deg
B. 20.56 deg
C. 26.56 deg
D. 32.56 deg
Solution:
⎡ 1 ⎤
−1 ⎡ 1 ⎤
α = tan −1 ⎢
⎥ = tan ⎢ 2 ⎥ = 26.56 deg
⎣ SR ⎦
⎣ ⎦
26. The cone angle of the pinion and the gear are 25° and 65° respectively. Find the speed ratio.
A. 1.5
B. 5.2
C. 4.23
Solution:
SR =
D. 2.14
sin β sin 65
=
= 2.14
sin α sin 25
27. A work at 1150 rpm drives a worm gear. The velocity is 15 to 1. A 10 hp motor is used to supply the worm with pitch gear diameter of 3 in. Find the
force on the worm.
A. 365.37 lbs
B. 465.37 lbs.
C. 565.37 lbs
D. 665.37 lbs
Solution:
Ft =
2T 2 ⎛ 63,000Hp ⎞ 2 ⎛ 63,000 × 10 ⎞
⎟= ⎜
= ⎜⎜
⎟ 3 ⎝ 1150 ⎟⎠ = 365.21lbs
D
D ⎝ Nm
⎠
28. A double thread worm has a lead of 1.5 in and pitch diameter of 3.5 in. If normal pressure angle is 14.5°, find the pressure angle of the worm.
A. 11.68°
B. 12.68°
C. 13.68°
D. 14.68°
Solution:
Then;
⎛ L ⎞
1.5 ⎞
⎟ = tan −1⎛⎜
λ = tan −1⎜⎜
⎟ = 7.768o
⎟
π
π
D
⎝ × 3.5 ⎠
w ⎠
⎝
⎛ tan φn ⎞
⎛ tan 14.5 ⎞
φ = tan −1⎜
⎟ = tan −1⎜
⎟ = 14.628o
⎝ cos λ ⎠
⎝ cos 7.768 ⎠
29. Find the angle of contact on the small pulley for a belt drive with center distance of 72 inches if pulley diameters are 6 in. and 12 in., respectively.
A. 180.60 deg
B. 243.40 deg
C. 203.61 deg
D. 175.22 deg
Solution:
θ = π−
D 2 − D1
12 − 6
180o
= π−
= 3.0582rad ×
= 175.22o
C
72
πrad
30. Determine the belt length of an open belt to connect the 6 cm and 12 cm diameter pulley at center distance of 72 cm.
A. 172.39 cm
B. 160.39 cm
C. 184.39 cm
D. 190.39 cm
Solution:
L=
2
2
π
(D1 + D2 ) + 2C + (D2 − D1 ) = π (6 + 12) + 2(72) + (12 − 6) = 172.39cm
2
4C
2
4(72)
3
31. A 3/8 inch flat belt is 12 inches wide and is used on 24 inches diameter pulley rotating at 600 rpm. The specific weight of the belt is 0.035 lb/in . If the
angle of contact is 150 degrees, the coefficient of friction is 0.3 and stress is 300 psi, how much power can it deliver?
A. 65.4 Hp
B. 69.5 Hp
C. 60.5 Hp
D. 63.5 Hp
Solution:
3
24 600
;
F1 = S ⋅ b ⋅ t = 300 × × 12 = 1350lbs
Vs = π ⋅ D ⋅ N = π ×
×
= 62.83fps
8
12 60
3
12 × 0.035 × × 12 × 62.832
12 ⋅ ρ ⋅ b ⋅ t ⋅ Vs2
8
=
= 231.707lbs
Fc =
32.2
g
⎞
⎛ ⎛⎜ 0.3×150×π ⎞⎟
⎟
⎜ ⎝
180 ⎠
⎛ efθ − 1 ⎞
e
1
−
⎟ = 608.42lbs
⎜
⎜
⎟
F = (F1 − Fc )
= (1350 − 231.707 )⎜
150×π ⎞ ⎟
⎜ efθ ⎟
⎛
×
0
.
3
⎜
⎟
⎝
⎠
⎜⎜ ⎝
180 ⎠ ⎟⎟
⎠
⎝ e
4
MACHINE DESIGN/SHOP PRACTICE
Hp =
TN m
Nm ⎛ F ⋅ D ⎞
600 ⎛ 608.42 × 24 ⎞
=
⎜
⎟=
⎜
⎟ = 69.5Hp
63,000 63,000 ⎝ 2 ⎠ 63,000 ⎝
2
⎠
32. A pulley has an effective belt pull of 3 kN and an angle of belt contact of 160 degrees. The working stress of belt is 2 MPa. Determine the thickness of
the belt to be used if width is 350 mm and coefficient of friction is 0.32.
A. 6.42 mm
B. 7.24 mm
C. 8.68 mm
D. 9.47 mm
Solution:
⎛ 160×π ⎞
⎟
180 ⎠
0.32×⎜
F1
⎝
= efθ = e
F2
F = F1 − F2
Then;
t=
= 2.444
therefore : F2 =
3 = F1 −
substituting
F1
2.444
F1
2.444
therefore ; F1 = 5.07
F1
5.07 × 103
=
= 7.24mm
S⋅ b
2 × 350
33. A pulley has a belt pull of 2.5 kN. If 20 Hp motor is use to drive the pulley, determine the belt speed.
A. 19.58 ft/sec
B. 5.97 ft/sec
C. 7.42 ft/sec
D. 10.86 ft/sec
Solution:
F = 2.5 kN ≈ 562.12 lbs
Vs =
550Hp 550 × 20
=
= 19.568ft / sec
F
562.12
34. A chain and sprocket has 18 teeth with chain pitch of ½ in. Find the pitch diameter of sprocket.
A. 0.879 in
B. 1.879 in
C. 2.879 in
Solution:
D=
D. 3.879 in
P
0.5
=
= 2.879in
⎛ 180 ⎞
⎛ 180 ⎞
sin ⎜
⎟ sin⎜
⎟
⎝ T ⎠
⎝ 18 ⎠
35. A chain and sprocket has 24 teeth with chain pitch of ½ in. If the sprocket turns at 600 rpm, find the speed of chain.
A. 601.72 fpm
B. 621.72 fpm
C. 641.72 fpm
D. 661.752 fpm
Solution:
V = π⋅D⋅ N = π×
P
0.5
× N = π×
× 600 = 601.72fpm
⎛ 180 ⎞
⎛ 180 ⎞
sin⎜
sin ⎜
⎟
⎟ × 12
⎝ T ⎠
⎝ 24 ⎠
36. A chain and sprocket has a pitch diameter of 28.654 in and there are 90 teeth available. Find the pitch of the chain.
A. ½ in
B. ¾ in
C. 1 in
D. 1 ¼ in
Solution:
⎛ 180 ⎞
⎛ 180 ⎞
P = D × sin ⎜
⎟ = 1in
⎟ = 28.654 × sin⎜
⎝ T ⎠
⎝ 90 ⎠
37. It is found that the load of 50 lb, an extension coil deflects 8.5 in. What load deflects the spring by 2.5 in?
A. 10.64 lb
B. 12.48 lb
C. 13.48 lb
D. 14.70 lb
Solution:
k=
F8.5 50
=
= 5.88lb / in
δ
8. 5
then;
F2.5 = k ⋅ δ = 5.88 × 2.5 = 14.70lb
38. Four compression coil spring in parallel support a load of 360 kg. Each spring has a gradient of 0.717 kg/mm.
A. 125.52 mm
B. 132.52 mm
C. 138.52 mm
D. 145.52 mm
Solution: δ =
F
360
=
= 125.52mm
4k 4(0.717)
2
39. Determine the permissible working stress of UNC bolts that that has a stress area of 0.606 in if material used is carbon steel.
A. 4055.5 psi
B. 5244.5 psi
C. 4675.5 psi
D. 4186.5 psi
Solution:
from Vallance;
Sw = C × As 0.418
where : C for carbon steel = 5000 and C for alloy steel = 15000
Sw = 5000 × 0.6060.418 = 4055.5psi
40. Compute the working strength of 1 1/2 in. bolt which if screwed up tightly in packed joint when the allowable working stress is 13,000 psi.
A. 11,465.5 lbs
B. 13,860.5 lbs
C. 11,212.5 lbs
D. 11,854.5 lbs
Solution:
(
from Machinery Handbook, Fw = St 0.55d − 0.25d
2
[ ( )
)
]
Fw = 13,000 0.55 1.52 − 0.25(1.5) = 11,212.5lbs
5
MACHINE DESIGN/SHOP PRACTICE
41. The total torque required to turn the power screw is 50 N.m. If the linear speed of screw is 7 ft/min and lead of 8 mm, find the horsepower input of the
power screw.
A. 2.86 Hp
B. 1.84 Hp
C. 2.14 Hp
D. 2.38 Hp
Solution: N m =
39.36 × 2.205 ⎞
⎛
⎜ 50 ×
⎟ × 304.8
T ⋅ Nm ⎝
9.8066 ⎠
Hp =
=
= 2.14Hp
63000
63000
Vm (8 × 12 × 25.4 )
=
= 304.8rpm
L
8
42. The root diameter of a double square thread power screw is 0.55 in. If the screw has a pitch of 0.2 in., determine the major diameter.
A. 0.524 in
B. 0.750 in
C. 0.842 in
D. 0.961 in
Solution: For square thread:
h=
p 0.2
=
= 0. 1
2
2
then;
Do = 2h + Di = 2(0.1) + 0.55 = 0.750in
43. A square thread screw has an efficiency of 70% when friction of threads is 0.10 and collar friction is negligible. Determine the lead angle.
A. 12.6°
B. 14.3°
C. 16.5°
D. 18.3°
Solution: For square thread power screw, neglecting the collar friction, e =
tan λ(1 − 0.1 tan λ )
× 100%
tan λ + 0.1
0.70 =
tan λ (1 − f tan λ )
× 100%
tan λ + f
Therefore; λ = 14.3°
44. An eyebolt is lifting a block weighing 350 lbs. The eyebolt is of SAE 1040 material with Su = 67 ksi and Sy = 55 ksi. What is the stress area (in inches
square) of the bolt if it is under the unified coarse series thread?
A. 1341
B. 0.1134
C. 0.991
D. 1043
Solution: From Faires, Fw =
Sy
6
(As )
3/ 2
Then,
⎛ 6 ⋅ Fw
As = 3 ⎜
⎜ Sy
⎝
2
2
⎞
⎟ = 3 ⎛⎜ 6 × 350 ⎞⎟ = 0.1134 in 2
⎜ 55,000 ⎟
⎟
⎝
⎠
⎠
45. In a brake, the tension on the tight side is thrice the slack side. If coefficient of friction is 0.25, find the angle of contact on the band,
A. 240.61 deg
B. 251.78 deg
C. 286.75 deg
D. 275.65 deg
Solution:
F1
= ef ⋅θ = 3
F2
then;
θ=
ln 3 180
×
= 251.78 deg
0.25 π
46. A steel band has a maximum tensile stress of 55 MPa and thickness of 4 mm. If the tension in tight side is 6 kN, what width of band should be used?
A. 25.25 mm
B. 27.27 mm
C. 28.28 mm
D. 29.29 mm
Solution: t =
F1
6 × 103
=
= 27.27 mm
St ⋅ b 55 × 4
47. Determine the torque can a cone clutch transmits if the angle of the conical elements is 10 degrees. The mean diameter of conical sections is 200 mm
and an axial force of 600 N is applied. Consider a coefficient of friction of 0.45.
A. 135.49 N.m
B. 155.49 N.m
C. 175.49 N.m
D. 195.49 N.m
Solution:
Tf = f ⋅
Fa D m
600 0.200
⋅
= 0.45 ×
×
= 155.49 N ⋅ m
sin θ 2
sin 10
2
48. A spherical tank 15 mm thick has an internal pressure of 5 MPa. The joint efficiency is 96% and stress is limited to 46875 kPa. Find the inner diameter
of the tank.
A. 150 mm
B. 510 mm
C. 450 mm
D. 540 mm
Solution:
Di =
4 ⋅ St ⋅ t ⋅ η 4 × 46.875 × 15 × 0.96
=
= 540mm
Pi
5
49. What is the kinetic energy of a 675 kg weight that is moving 24 kph?
A. 13,000 N.m
B. 14,000 N.m
C. 15,000 N.m
D. 16,000 N.m
2
Solution:
KE =
1
1
⎛ 24 × 1000 ⎞
m ⋅ V 2 = × 675 × ⎜
⎟ = 15,000 N ⋅ m
2
2
⎝ 3600 ⎠
50. A mass weighing56 lb rests on a horizontal surface. If the force needed to move along the surface is 20 lbs. determine the coefficient of friction.
A. 0.01
B. 0.112
C. 0.36
D. 0.28
Solution:
W = Fn and f ⋅ Fn = F
51. Most popular soldering material.
A. 10/80% tin and lead
therefore; f =
B. 45/55% tin and lead
F
F
20
=
=
= 0.36
Fn W 56
C. 50/50 % tin and lead
6
D. 60/40% tin and lead
MACHINE DESIGN/SHOP PRACTICE
52. The following pertain to joining of metals, EXCEPT:
A. welding
B. soldering
53. Liners normally made of:
A. cast iron
B. alloyed bronze
54. A furnace used in melting non-ferrous metals.
A. cupola furnace
B. crucible furnace
D. brazing
C. casting
C. alloyed steel
D. alloyed aluminum
C. induction furnace
D. normalizing furnace
55. The best instrument for measuring a thousand of an inch.
A. micrometer
B. tachometer
C. caliper
D. pyrometer
56. Machine tool used for laying straight lines on metal surfaces made of sharp tool steel.
A. plain scriber
B. a trammel
C. hermaphrodite caliper
D. divider
57. A weld of approximately triangular cross-section that join two surfaces at approximately right angles as in lap joint, tee joint, corner joint:
A. single welded lap joint
B. fillet weld
C. tack weld
D. butt weld
58. A weld place in a groove between two abutting members.
A. full-fillet weld
B. tack weld
C. butt weld
D. fillet weld
59. Imparts of reciprocating motion to a single-point cutting tool.
A. dividing head
B. slotting attachment
C. circular pitch
D. circular milling attachment
60. All ate associated with standard material specification, EXCEPT:
A. American Iron and Steel Institute
B. Society of Automotive Engineers
C. Southeast Asia Iron and Steel Institute
D. American Society for Testing Materials
61. In grater quantity, this element is harmful to the ferrous metal:
A. sulfur
B. silicon
C. zinc
D. aluminum
62. Galvanized steel plate is plate coated with:
A. aluminum
B. tin
C. zinc
D. manganese
63. Major component of bronze casting:
A. aluminum
B. manganese
C. tin
D. lead
64. Heating of the metal to a temperature above the critical temperature and then cooling slowly usually in the furnace to reduce the hardness and improve
the machinability is called:
A. annealing
B. tempering
C. normalizing
D. quenching
65. One of the following materials is unsuitable as a bearing:
A. Teflon
B. low carbon steel
C. cast iron
D. nylon
66. Which is not a generally used standard?
A. ASTM
B. SAE
C. IPS
D. AISI
67. Alloy steel known for its resistance to corrosion, abrasion and wear that is usually ideal for mill grinding of ore in cement and concentrator application. It
is usually combined with molybdenum to increase the depth hardening:
A. manganese chromium steel
B. chromium molybdenum steel
C. chrome-nickel-moly steel
D. manganese-moly steel
68. Commonly utilized/cheapest shaft material available in the markets with carbon content of 0.38 to 0.34% C.
A. SAE 4132
B. SAE 4320
C. SAE 1030
D. SAE 4130
69. It is hardening treatment whereby a cast metal is being heated to a very high temperature then suddenly subjected to rapid cooling to improve
hardenability or wear resistance is called:
A. normalizing
B. tempering
C. quenching
D. annealing
70. SAE steel that responds to heat treatment:
A. SAE 1060
B. SAE 1117
C. SAE 1030
D. SAE 1020
71. Which of the following metals is non-magnetic?
A. manganese steel
B. cast steel
C. alloy steel
D. cast iron
72. Muntz metal contains;
A. copper-nickel
B. copper-zinc
C. copper-tin
D. copper-aluminum
73. A babbit is:
A. a eutectic iron and iron phosphide
B. a gadget for measuring volume
C. a measure of magnetic induction produced in a material
D. antimony bearing lead or tin alloy
74. Machining properties of steel can be improved by adding:
A. sulphur, lead, phosphorus B. silicon, aluminum, titanium C. vanadium, aluminum
D. chromium, nickel
75. A cold chisel is made of:
A. mild steel
B. HSS
C. cast iron
D. high carbon steel
o
76. A welding operation in which a non-ferrous filler metal melts at a temperature below that of the metal joined but is heated above 450 C.
a. Brazing
b. Spot welding
c. Gas welding
d. Projection welding
77. The operation of cooling a heated piece of work rapidly by dipping it in water, brine or oil.
a. tempering
b. annealing
c. quenching
d. normalizing
78. An amorphous solid made by fusing silica with a basic oxide.
a. pearlite
b. rock
c. silicon
d. glass
79. A soft yellow metal, known since ancient times a precious metal which all material values are based.
a. solidus
b. bronze
c. gold
d. austenite
80. Flexible used to seal pressurized fluids, normally under dynamic conditions.
a. Packings
b. Teflon
c. Seals
d. Safety shield
81. A stainless steel is obtained principally by the use of the following alloying element.
a. Chromium
b. Tungsten
c. Carbon
82. A hand tool used to measure tension on bolts.
a. indexer
b. torque wrench
c. torsionmeter
83. The permissible variation in the size of a dimension; the difference between the limits of size.
a. allowance
b. variance
c. clearance
84. A gear with teeth on the outer cylindrical surface.
a. outer gear
b. external gear
c. spiral gear
85. The diameter of a circle coinciding with the top of the teeth of an internal gear.
a. pitch diameter
b. root diameter
c. internal diameter
7
d. Phenol
d. tensionmeter
d. tolerance
d. helical gear
d. central diameter
MACHINE DESIGN/SHOP PRACTICE
JCSF ENGINEERING REVIEW CENTER
# 2 Alvaran’s Apartment, Purok 7, Halang
City of Calamba, Laguna
MACHINE DESIGN AND SHOP PRACTICE
(Refreshers Trivia # 13 for September 2012 Board Examination)
Prepared by: Jose R. Francisco, PME
September 2012
MULTIPLE CHOICE QUESTIONS
Select the best answer from each of the following questions. On the answer sheet provided, shade the box that corresponds to your choice. Strictly no
erasures allowed.
1.
For a bolted connection, specification suggests that a high grade material of 13 mm bolt be tightened to an initial tension of 55 000 N. What is the
appropriate tightening torque?
a) 134 N-m
b) 143 N-m
c) 341 N-m
d) 431 N-m
Solution:
T = C D Fi = (0.20 )(0.013 m )(55 000 N ) = 143 N ⋅ m
Note: Initial Tension and tightening Torque,
T = C D Fi
Fi = initial tension, N, kN, lb
C = torque coefficient
C = 0.15 (for lubricated bolts)
Where, T = tightening torque, N-m, kN-m, in-lb
D = bold nominal diameter, inch, mm
C = 0.20 (for as received bolts)
2.
A 74.6 kW engine of a hoist is capable of lifting 44 500 N of load at a height of 6.10 m in 10 seconds. What is the efficiency of the machine?
a) 36.39 %
b) 39.36 %
c) 63.39 %
d) 93.36 %
Solution:
3.
⎛ 16 ⎞
Vm = π D n = (π) ⎜ ⎟ (450) = 1884.96 fpm
⎝ 12 ⎠
⎛1⎞
W (h + δ ) = ⎜ ⎟ F δ
⎝2⎠
F=
2 W (h + δ ) 2 (100)(18 + 6)
=
= 800 lb
6
δ
2
Determine the permissible working stress of a UNC bolt that has a stress area of 0.606 in if the material used is carbon steel.
a) 4055.49 psi
b) 4505.49 psi
c) 4550.49 psi
d) 4455.09 psi
Solution:
s w = C (A r )0.418 = (5000 )(0.606)0.418 = 4055.49 psi
Note: From Vallance, p138. Bolt permissible stress,
6.
s w = C (A r )0.418
Applied load,
Fa = s w A r = C (A r )1.418
Where, C = 5000 for carbon steel bolt
C = 15 000 for alloy-steel bolts
C = 1 000 for bronze bolts
Compute the working strength of 1.5 inches bolt which is screwed up tightly in packed joint when the allowable working stress is 13000 psi.
a) 11 212.5 lb
b) 10 212.5 lb
c) 12 212.5 lb
d) 13 212.5 lb
Solution: From Machinery’s Handbook,
Where, W = working strength, lb
7.
27.145
(100 % ) = 36.39 %
74.6
A weight of 100 lb strikes a coil spring from a height of 18 inches and deflects the spring of 6 inches. Find the average force acting on the spring.
a) 800 lb
b) 600 lb
c) 900 lb
d) 700 lb
Solution:
5.
η=
A machine shaft is mounted with 16 inches diameter pulley running at 450 rpm. Find the peripheral speed, in fpm.
a) 1588
b) 1858
c) 1885
d) 5881
Solution:
4.
⎛ 6.10 m ⎞
⎟⎟ = 27 145 W = 27.145 kW
W = F ⋅ V = (44 500 N )⎜⎜
⎝ 10 sec onds ⎠
(
[
)
]
W = s t 0.55 d 2 − 0.25 d = (13 000) 0.55(1.5)2 − 0.25(1.5) = 11 212.5 lb
st = allowable working stress, psi
d = nominal diameter, inch
3
A 2-inch shaft is supported by bearing 90 inches apart. The shaft carries no rotating discs; its weight is 0.28 lb/in , its modulus of elasticity is 30 x 10
psi, and it has a uniform (round) cross section. Find the second critical speed, in rpm.
a) 4217.28 rpm
b) 4172.28 rpm
c) 4228.17 rpm
d) 4712.28 rpm
Solution: Lowest critical speed,
⎡ 2 ⎤
⎛ D⎞
N = 4270 000 ⎜ 2 ⎟ = (4 270 000 ) ⎢
⎥ = 1054.32 rpm
2
⎝L ⎠
⎣⎢ (90 ) ⎦⎥
1
6
MACHINE DESIGN/SHOP PRACTICE
Second Critical Speed,
N 2 = 4 (1054.32 ) = 4217.28 rpm
Note: The next critical speeds from the lowest critical speed can be found by multiplying by 4, 9, 16, 25, and so on.
8.
In 1-inch-diameter shaft has a single disc weighing 75 lb mounted midway between two bearings 20 inches apart. Find the lowest critical speed in rpm.
Neglect the weight of the shaft.. Assume that the modulus of elasticity is 30 000 000 psi.
a) 5763.43 rad/s
b) 301.77 rad/s
c) 1207.09 rad/s
d) 401.77 rad/s
Solution: For the disc mounted midway between bearings (neglecting shaft weight),
ω cr =
Where,
9.
I=
576 E I g
3
=
576 (30 000 000)(0.0982)(32.2 )
(75)(20)3
WL
= 301.77 rad / s
π 4 ⎛ π⎞ 4
D = ⎜ ⎟ (1) = 0.0982 in 4
32
⎝ 32 ⎠
Compute the centrifugal force of a leather belt with the following specifications: width = 4 inches, thickness = 0.25 inch, belt speed = 3601 fpm.
a) 47 lb
b) 74 lb
c) 57 lb
d) 75 lb
2
Solution:
⎛ 3601 ⎞
12 (0.035)(4 )(0.25)⎜
⎟
12 γ b t Vs2
⎝ 60 ⎠
Fc =
=
= 46.98 lb
g
32.2
Note: Specific weight of leather belt = 0.035 lb/in
3
Specific weight of rubber belt = 0.045 lb/in
3
10. A one-fourth inch thick belt transmits 30 Hp while running on a 2-foot pulley rotating at 600 rpm. The allowable belt stress is 500 psi; the angle of
o
3
contact is 150 . Find the belt width required, assuming the coefficient of friction is 0.4 and the specific weight of the belt material is 0.035 lb/in .
a) 2.61 inches
b) 3.61 inches
c) 4.61 inches
d) 5.61 inches
Solution:
⎛ 2 ⎞⎛ 63 000 Hp ⎞ 2 (63 000)(30)
Ft = ⎜ ⎟⎜
= 262.5 lb
⎟=
(2)(12)(600)
n
⎝ D ⎠⎝
⎠
33 000 Hp (33 000 )(30)
Ft =
=
= 262..61 lb
Vm
3769.91
⎛ 12 γ V22
Ft = F1 − F2 = bt ⎜ s −
⎜
g
⎝
b=
⎞ ⎛ e fθ − 1 ⎞
⎟⎜
⎟
⎟ ⎜ e fθ ⎟
⎠
⎠⎝
Vm = π D n = (π )(2 )(600) = 3769.91 fpm
b=
Ft
⎛ 12 γ Vs2
t ⎜s −
⎜
g
⎝
⎞⎛ e fθ − 1 ⎞
⎟⎜
⎟
⎟⎜ e fθ ⎟
⎠
⎠⎝
262.61
⎡
⎛ 3769.91 ⎞
12 (0.035) ⎜
⎢
⎟
⎝ 60 ⎠
0.25⎢⎢500 −
32.2
⎢
⎢⎣
2
⎤
⎥ ⎛ 0.40(150 )(π / 180o ) ⎞
−1 ⎟
⎥⎜e
⎥ ⎜ e 0.4(150 )(π / 180 ) ⎟
⎠
⎥⎝
⎥⎦
=
262.61
= 3.608 inches
⎛ 1.8497 ⎞
112.13⎜
⎟
⎝ 2.8497 ⎠
11. A triple-threaded square power screw with a root diameter of 2 inches and 2 threads per inch is used in conjunction with a collar with an outer diameter
of 4 inches and an inner diameter of 2.5 inches. Find the total torque necessary to raise the load of 3000 lb. The coefficient of friction of 0.2 for both
threads and collar.
a) 2445 lb
b) 2544 lb
c) 2454 lb
d) 4245 lb
Solution: Pitch,
Pa =
1
1
= = 0.5 inch / thread
TPI 2
Major diameter,
⎛P ⎞
D o = D i + 2h = D i + 2⎜⎜ a ⎟⎟ = D i + Pa = 2 + 0.5 = 2.5 inches
⎝ 2 ⎠
D i + D o 2 + 2.5
=
= 2.25 inches
2
2
3
3
3
3
⎛ 2 ⎞ ⎛ ro − ri ⎞⎟ ⎛ 2 ⎞ ⎡ (2) − (1.25) ⎤
Collar mean radius or friction radius, rc = ⎜ ⎟ ⎜
=
⎜
⎟
⎥ = 1.654 inches
⎢
⎝ 3 ⎠ ⎜⎝ ro2 − ri2 ⎟⎠ ⎝ 3 ⎠ ⎢⎣ (2 )2 − (1.25)2 ⎥⎦
Mean diameter,
Dm =
2
MACHINE DESIGN/SHOP PRACTICE
Tanλ =
Lead Angle,
Total Torque,
N P
(3)(0.5) = 0.21221
L
= t a =
πD m
πD m
π (2.25)
T = Tc + Ts = f c W rc +
λ = 11.98 o
W D m ⎛ Tanλ + f ⎞
⎜
⎟
2 ⎝ 1 − f tan λ ⎠
⎡ 3000(2.25) ⎤ ⎡ 0.21221 + 0.2 ⎤
T = (0.2 )(3000)(1.654) + ⎢
⎥ ⎢1 − 0.2(0.21221) ⎥ = 2445.27 in ⋅ lb
2
⎣
⎦⎣
⎦
12. In problem # 17 above, determine the efficiency of the power screw.
a) 25.25 %
b) 39.29 %
c) 29.29 %
Solution:
e=
tan λ(1 − f tan λ )(100 % )
⎛f D
tan λ + f + ⎜⎜ c c
⎝ Dm
⎞
⎟⎟(1 − f tan λ )
⎠
=
(0.21221) [1 − (0.2)(0.21221)](100 % )
= 29.29 %
⎡ 0.2 (3.308) ⎤
[1 − (0.2)(0.21221)]
0.21221 + 0.2 +
⎢
⎣
2.25
13. If the depth of water in a swimming pool is 5 m, what is its depth in fathom?
a) 2.73 fathoms
b) 3.72 fathoms
c) 1.73 fathom
Solution:
d) 24.29 %
⎥
⎦
d) 7.13 fathoms
ft ⎞⎛ 1 fat hom ⎞
⎛
⎟ = 2.73 fat hom
depth = (5 m )⎜ 3.28 ⎟⎜⎜
m ⎠⎝ 6 feet ⎟⎠
⎝
3
14. If the volume of a tank is 30 barrels, what is its volume in m ?
3
3
b) 7.74 m
a) 4.77 m
Solution:
c) 3.77 m
3
3
⎛ 42 gallons ⎞⎛ 3.7854 liters ⎞⎛ 1 m 3 ⎞
⎟ = 4.77 m 3
⎟⎟⎜⎜
⎟⎟⎜
V = (30 barrels)⎜⎜
⎜
⎟
⎝ 1 barrel ⎠⎝ 1 gallon ⎠⎝ 1000 liters ⎠
15. If the length of the fence is 5 furlongs, what is its length in yards?
a) 1000 yards
b) 1150 yards
c) 1100 yards
Solution:
d) 5.77 m
d) 1150 yards
⎛ 220 yards ⎞
⎟⎟ = 1100 yards
L = (5 furlong )⎜⎜
⎝ 1 Furlong ⎠
16. During a punching of 350 kg flywheel the speed varies from 200 rpm to 180 rpm with 1 m mean diameter. Determine the kinetic energy needed.
a) 3.65 kJ
b) 6.28 kJ
c) 4.51 kJ
d) 5.62 kJ
Solution:
πDn 1 π(1 m )(200 )
πDn 2 π(1 m )(180 )
=
= 10.47 m / s
V2 =
=
= 9.42 m / s
60
60
60
60
m 2
⎛ 350 kg ⎞
2
2
∆KE =
V1 − V22 = ⎜
⎟ (10.47 ) − (9.42) = 3 654.8 J = 3.655 kJ
2
2
⎝
⎠
V1 =
(
[
)
]
17. The energy required to punch a square from 20 mm thick plate is 10 kJ. If the ultimate strength of the plate is 420 MPa, determine the maximum sides
of square that can be punched.
a) 45 mm
b) 30 mm
c) 60 mm
d) 55 mm
Solution:
∆KE =
(
)
( )
1
1
1
F ⋅ t p = 4bt p t p s u = (4b )t 2p s u = 2b t p 2 s u
2
2
2
10 000 000 N ⋅ mm
∆KE
b= 2 =
= 29.76 mm
2 t p s u 2(20 mm )2 420 N / mm 2
(
)
18. Determine the diameter of a steel rod 6 inches long if it is to resist the impact of a weight of W = 500 lb dropped through a distance of 2 inches. The
maximum computed stress is to be 20 ksi.
a) 5.65 inches
b) 6.55 inches
c) 4.65 inches
d) 6.45 inches
Solution: Maximum deflection due to the maximum stress,
Solving for cross sectional area,
Solving for the Diameter,
D=
s=
2W ⎛h ⎞
⎜ + 1⎟
A ⎝δ ⎠
4A
=
π
δ=
s L (20 000 psi )(6 inches )
=
= 0.004 inch
E
30 x 10 6 psi
A=
2 W ⎛ h ⎞ ⎡ 2(500 lb ) ⎤⎛ 2
⎞
+ 1⎟ = 25.05 in 2
⎜ + 1⎟ = ⎢
⎥⎜
2
s ⎝ δ ⎠ ⎢⎣ 20 000 lb / in ⎥⎦⎝ 0.004 ⎠
4 (25.05)
= 5.65 inches
π
3
MACHINE DESIGN/SHOP PRACTICE
19. The energy required to punch a square hole from 20 mm thick plate is 10 kJ. If the ultimate strength of the plate is 420 MPa, with factor of safety of 4,
determine the maximum sides of square that can be punched.
a) 25 mm
b) 35 mm
c) 30 mm
d) 20 mm
Solution: Punching Force,
b=
F=
F
=
4su tp
2 (∆KE ) 2(10 000 N ⋅ m )
=
= 1 000 000 N = 1 000 kN
tp
0.02 m
(
1 000 000 N
)
4 420 N / mm 2 (20 mm )
= 29.76 mm ≈ 30 mm
20. A flywheel stops in 15 seconds from a speed of 220 rpm. Compute the number of turns the flywheel makes before it stops.
a) 27.5 turns
b) 172.8 turns
c) 25.7 turns
d) 52.7 turns
Solution: Acceleration,
α=
Angular displacement,
ω f − ω o 0 − 23.04
2 π n 2 (π )(220 )
=
= − 1.536 rad / s 2
ωo =
=
= 23.04 rad / s
t
15
60
60
α
⎛ − 1.536 ⎞
2
θ = ω o t + t 2 = (23.04 )(15) + ⎜
⎟ (15) = 172.8 radians = 27.5 revolutions
2
2
⎝
⎠
21. Determine the cutting speed, in fpm, of a workpiece with 2 inches diameter and running at 100 rpm.
a) 56.23 fpm
b) 52.36 fpm
c) 36.52 fpm
d) 23.56 fpm
Solution:
⎛ 2⎞
V = π D n = (π ) ⎜ ⎟ (100 ) = 52.36 fpm
⎝ 12 ⎠
22. A rectangular beam 60 mm wide and 100 mm deep is used as a cantilever, 2 m long. A 40 kg mass falls through a height of 0.20 m before striking the
free end. Compute the maximum bending stress and deflection caused by the impact. Neglect the mass of the beam and assume that the 40 kg mass
remains in contact with the beam.
a) 162 MPa
b) 261 MPa
c) 126 MPa
d) 621 MPa
Solution: Static stress,
⎛h⎞
mg L ⎜ ⎟
2
Mc W L c
⎝ 2 ⎠ 6 m g L 6 (40 kg ) 9.8066 m / s (2 m )
=
=
=
=
= 7 845 280 N / m 2 = 7.85 MPa
s st =
3
2
(
)(
)
0
.
06
m
0
.
10
m
I
I
bh
bh
12
b h 3 (0.06 )(0.10 )3
Moment of Inertia, I =
=
= 5 x 10 − 6 m 4
12
12
(
δ=
Deflection of Cantilever,
W L3
(40)(9.806)(0.10)3
=
= 1.046 x 10 −3 m = 1.046 mm
3 E I 3 20 000 000 000 N / m 2 5 x 10 − 6 m 4
(
Maximum Stress caused by the Impact,
s max
)
)(
s max =
W W ⎛ 2hEA ⎞
⎜1 +
⎟
+
A A ⎜⎝
W L ⎟⎠
⎡
2 (0.20 ) ⎤
= 7.85 + 7.85⎢1 +
⎥
−3
⎢⎣ 1.046 x 10 ⎥⎦
)
0.5
⎛ 2h ⎞
= s max = s st + s st ⎜1 +
⎟
δ ⎠
⎝
0.5
Where,
δ=
WL
AE
0.5
= 161.56 MPa ≈ 162 MPa
23. A double thread worm gear has a pitch of 1.125 inches and a pitch diameter of 3 inches. It has a coefficient of friction of 0.20 and normal pressure
o
angle of 14.5 . The worm is supplied by 12 Hp at 1200 rpm motor. Find the tangential force on the gear. The worm is a left hand thread.
a) 420 lb
b) 897 lb
c) 798 lb
b) 879 lb
Solution:
⎛ L
λ = tan −1 ⎜⎜
⎝ π Dw
⎞
⎛N P
⎟ = tan −1 ⎜ t a
⎟
⎜ πD
w
⎠
⎝
⎞
⎡ 2 (1.125) ⎤
o
⎟ = tan −1 ⎢
⎥ = 13.427
⎟
⎣ π (3) ⎦
⎠
⎞⎛ 63 000 Hp ⎞ ⎛ 2 ⎞ ⎡ 63 000 (12 ) ⎤
⎟⎜
⎟ =⎜ ⎟⎢
⎥ = 420 lb
⎟⎜
⎟ ⎝3⎠
nw
⎣ 1200 ⎦
⎠⎝
⎠
Tangential load of worm,
⎛ 2
Ftw = ⎜⎜
⎝ Dw
Tangential load on gear,
⎛ cos 14.5 o cos 13.427 o − 0.20 sin 13.427 o
⎛ cos φ n cos λ − f sin λ ⎞
⎟⎟ = (420 )⎜
Ftg = Ftw ⎜⎜
⎜ cos 14.5 o sin 13.427 o + 0.20 cos 13.427 o
⎝ cos φ n sin λ + f cos λ ⎠
⎝
4
⎞
⎟ = 896.65 lb
⎟
⎠
MACHINE DESIGN/SHOP PRACTICE
o
24. A double thread worm has a lead angle of 7.25 and pitch radius of 2.5 inches. Determine the pitch of the worm.
a) 1.5 inch
b) 2 inches
c) 1 inch
d) 0.75 inch
Solution:
L = πD w tan λ = 2πR tan λ = 2(π)(2.5) tan 7.25 o = 1.9983 inches
Pa =
L 1.9983
=
= 0.9992 inch ≈ 1 inch
Nt
2
25. Determine the belt length of an open belt to connect the 6 cm and 12 cm diameter pulleys at a center distance of 72 cm.
a) 127.4 cm
b) 142.7 cm
c) 172.4 cm
d) 147.2 cm
Solution:
(D − D1 )2 ⎛ π ⎞
(12 − 6)2 = 172.4 cm
⎛π⎞
L = ⎜ ⎟(D1 + D 2 ) + 2C + 2
= ⎜ ⎟(6 + 12 ) + 2(72 ) +
4C
4(72 )
⎝2⎠
⎝4⎠
26. Determine the depth of the ACME thread if the pitch is 1.25 inches.
a) 0.625 inch
b) 0.635 inch
c) 1.25 inches
Solution:
d) 0.750 inch
h = 0.5 Pa + 0.01 = (0.5)(1.25) + 0.01 = 0.635 inch
27. A chain and sprocket has 18 teeth with chain pitch of 0.5 inch. Find the pitch diameter of the sprocket.
a) 2.88 inches
b) 2.66 inches
c) 2.55 inches
d) 2.77 inches
Solution:
D=
Pa
⎛ 180
sin ⎜
⎜ T
⎝
⎞
⎟
⎟
⎠
o
=
0.50
⎛ 180 o
sin ⎜
⎜ 18
⎝
⎞
⎟
⎟
⎠
= 2.879 inches
28. On a brake drum the difference in tension between the tight side and slack side is 5 kN. If the the ratio in band tensions is 3, determine the tension in
the tight side.
a) 2.75 kN
b) 3.75 kN
c) 4.75 kN
d) 1.75 kN
Solution:
F1 = 3 F2
F1 = 5 − F2 = 5 −
F1
3
F1 = 3.75 kN
29. A shaft has a critical speed of 800 rpm. If the shaft diameter is doubled, what will be the critical speed?
a) 1600 rpm
b) 3600 rpm
c) 800 rpm
d) 900 rpm
Solution:
⎛ D⎞
n cr = 4 270 000 ⎜ 2 ⎟
⎝L ⎠
D
2
L
=
n
800
=
4 270 000 4 270 000
⎛ 800 ⎞
n cr = (4270 000 )(2 )⎜
⎟ = 1600 rpm
⎝ 4270000 ⎠
30. A 1200 mm cast iron pulley is fastened to 112.5 mm shaft by means of a 28.13 mm square key 175 mm long. The key and shaft have a shearing stress
of 14 000 psi. Determine the force acting at the pulley that will shear the key.
a) 4541.83 kg
b) 4252.83 kg
c) 5441.83 kg
d) 4145.83 kg
⎛ s bLD ⎞
2⎜ s
⎟
⎛ D ⎞
2T
2 ⎠
⎟ = (14 000)⎛⎜ 28.13 ⎞⎟⎛⎜ 175 ⎞⎟⎛⎜ 112.5 ⎞⎟ = 10 014.74 lb
= ⎝
= ss bL⎜
Solution: Fp =
⎜
⎟
⎜
⎟
Dp
Dp
⎝ 25.4 ⎠⎝ 25.4 ⎠⎝ 1200 ⎠
⎝ Dp ⎠
31. A 75-mm diameter shaft is transmitting 300 kW at 600 rpm. A flange coupling is used and has 6 bolts, each 18 mm in diameter. Find the required
diameter of the bolts circle based on an average shearing stress of 27.5 MPa.
a) 8.95 inches
b) 5.98 inches
c) 9.85 inches
d) 7.95 inches
Solution: D B =
8T
π ssd n B
2
=
8(30)P
π d ssn n B
2 2
=
8(30)(300 )
π (0.018)2 (27 500 )(600 )(6 )
2
= 0.2274 m = 227.4 mm
32. What is the working strength of a 2 inches bolt which is screwed up tightly in a packed joint when the allowable working stress is 12 000 psi?
a) 20 120 lb
b) 20 100 lb
c) 20 400 lb
d) 20 200 lb
Solution: From Machinery’s handbook:
(
[
)
]
W = s t 0.55d 2 − 0.25d = (12 000 ) 0.55(2 )2 − 0.25(2) = 20 400 lb
33. A vise is equipped with a 1-inch single square thread, with 4 threads per inch. The frictional radius of the collar is 0.5 inch. The coefficient of friction for
both the collar and threads is 0.20. How much external torque must be applied to produce a force of 200 lb against the jaws of the vise?
a) 39.73 in-lb
b) 33.97 in-lb
c) 37.93 in-lb
d) 39.37 in-lb
5
MACHINE DESIGN/SHOP PRACTICE
Vise Jaw
Screw
Collar
Nut
Handle
F = 200 lb
Solution:
For the thread pitch,
p=
1
1
= = 0.25 inch
Number of Threads per Inch 4
For the minor diameter, Di = Do – p = 1 – 0.25 = 0.75 inch
Do + Di 1 + 0.75
=
= 0.875 inch
2
2
⎛ L ⎞
p ⎞
−1 ⎛
−1 ⎛ 0.25 ⎞
λ = tan −1 ⎜
= tan −1 0.09095 = 5.197o
⎟ = tan ⎜
⎟ = tan ⎜
⎟
⎝ 0.875π ⎠
⎝ πD m ⎠
⎝ πD m ⎠
For the mean or pitch diameter of the screw,
For the lead angle,
Dm =
Solving for the torque required to overcome the collar friction,
Tc =
fFDc ( 0.2 )( 200 )( 0.5 )
=
= 20 in ⋅ lb
2
2
Solving for the torque required to overcome the thread friction,
Ts =
FD m ⎛ tan λ + f ⎞ 200 ( 0.875 ) ⎡ 0.09095 + 0.2 ⎤
⎢
⎥ = 25.93 in ⋅ lb
⎜
⎟=
2 ⎝ 1 − f tan λ ⎠
2
⎢⎣ 1 − 0.2 ( 0.9095 ) ⎥⎦
Solving for the total torque, T = Ts + Tc = 25.93 + 20 = 45.93 inches
ans.
34. Determine the outside diameter of a hollow shaft whose inside diameter is 1 inch if it is to replace a 1.5-inch diameter solid shaft for power
transmission. The shafts have equal torsional strengths.
a) 2.25 in.
b) 1.5 in.
c) 1.75 in.
d) 2.0 in.
Solution:
Ss solid =
16T
πD 3
Ss hollow =
16TD o
π(D o4 − D14 )
Thus , for equal strength , D o4 − 1 = D o (1.5) 3 : D o = 1.589in. Use the next higher standard size, Do=1.75 in.
35. What length of a square key is required for a 4-in diameter shaft transmitting 1000 hp at 1000 rpm? The allowable shear and compressive stresses in
the key are 15 ksi and 30 ksi, respectively.
a) 53.34 mm
b) 54.33 mm
c) 50.34 mm
d) 55.34 mm
Solution: Transmitted torque,
T=
63000 Hp 63000(1000)
=
= 63 000 in ⋅ lb
n
1000
D
, for good proportion
4
2T
2 (63 000 )
=
= 2.1 inches
Key length based on shear, L =
s s bD 15 000 (1)(4 )
Key width,
b≈
Key length based on compression,
L=
4T
4 (63 000 )
=
= 2.1
s c t D 30 000 (1)(4)
Therefore, use L = 2.1 inches
6
36. A steel shaft 1.4375 inches in diameter transmits 40 Hp at 1400 rpm. Assuming a modulus of rigidity of 12 x 10 psi, find the torsional deflection of the
shaft in degrees per foot length.
a) 0.246
b) 0.624
c) 0.426
d) 1.246
Solution:
θ T
32 T
32 (63 000 Hp )
32 (63 000)(40 )(12 )
=
=
=
=
4
4
4
L JG π D G
πn D G
π (1400 )(1.4375) 12 x 106
(
6
)
⎛ 180o ⎞
⎜
⎟
⎜ π ⎟ = 0.246 radian
⎝
⎠
MACHINE DESIGN/SHOP PRACTICE
37. A solid disk flywheel has a diameter of 1.5 m, and a mass of 800 kg. What torque is needed to produce an angular acceleration of 100 revolutions per
minute, per second?
a) 3265 N-m
b) 5236 N-m
c) 2356 N-m
d) 6325 N-m
Torque = Mass Moment of Inertia x AngularAcceleration = I α
Solution:
Where, I = 1 mr 2 , for cylinders;
I=
2
1
(800 kg )(1.5 / 2) 2 m 2 = 225 kg ⋅ m 2
2
Then, T = ( 225) kg − m 2 ⎡100( 2π) ⎤ rad = 2356 .2 N ⋅ m
⎥ 2
⎢
⎣
60
⎦ s
38. Find the pressure required to punch a 2 inches diameter hole through a 0.25 inch thick brass plate.
a) 40 tons
b) 32.5 tons
c) 20.5 tons
Solution:
d) 35 tons
F = 65 d t = (65)(2)(0.25) = 32.5 tons
th
[For steel plate use 80 as constant] (From Machinery’s Hand Book, 26 Ed.)
39. Compute the working strength of 1.5 inches bolt which is screwed up tightly in packed joint when the allowable working stress is 13 000 psi.
a) 12 121.5 lb
b) 11 212.5 lb
c) 21 211.5 lb
d) 12 211.5 lb
Solution:
(
[
)
]
W = St 0.55 D 2 − 0.25D = (13 000 ) (0.55)(1.5)2 − (0.25)(1.5) = 11 212.5 lb
th
[From Machinery’s Hand Book, 26 Ed., p1489]
40. Determine the frictional Power acting on a collar loaded with 100 kg weight. The collar has an outside diameter of 100 mm and an inside diameter of 40
mm. The collar rotates at 1000 rpm and the coefficient of friction between the collar and the pivot surface is 0.15.
a) 572 W
b) 527 W
c) 752 W
d) 275 W
Solution: rf
3
3
3
3
⎛ 2 ⎞⎛ r − r ⎞ ⎛ 2 ⎞ ⎡ (50 ) − (20 ) ⎤
= ⎜ ⎟⎜⎜ o2 i2 ⎟⎟ = ⎜ ⎟ ⎢
⎥ = 37.14 mm = 0.03714 m
⎝ 3 ⎠⎝ ro − ri ⎠ ⎝ 3 ⎠ ⎣⎢ (50 )2 − (20 )2 ⎦⎥
Tf = f W rf = (0.15)(100 kg )(9.8066 N / kg )(0.03714 m ) = 5.464 N ⋅ m
Pf =
π n Tf
π (1000 )(5.464 )
=
= 572.2 W = 0.572 kW
30
30
41. A solid shaft 48.2 cm long is used for transmission of mechanical power at a rate of 37 kW running at 1760 rpm. The torsional stress is 8.13 MPa. What
is the diameter of the shaft?
a) 45 mm
b) 50 mm
c) 55 mm
d) 30 mm
Solution:
1
1
30 P (30 )(37 )
T=
=
= 0.20075 kN ⋅ m = 200.75 N ⋅ m
πn
π (1760 )
⎛ 16 T ⎞ 3 ⎡16 (200 750 N ⋅ mm ) ⎤ 3
⎟ =⎢
D = ⎜⎜
⎥ = 50.10 mm
⎟
2
⎢⎣ π 8.13 N / mm
⎝ π Ss ⎠
⎦⎥
(
)
42. An internal gear is set up with a 127-mm diameter pinion and center distance of 457.2 mm. Determine the diameter of the internal gear.
a) 1140.4 mm
b) 1410.4 mm
c) 1041.4 mm
d) 1104.4 mm
Solution:
D 2 = 2C + D1 = 2(457.2) + 127 = 1041.4 mm
43. Calculate the thickness of a vertical cylindrical steel air receiver with 30 inches diameter and pressure load of 120 psi. The design stress is 8000 psi.
a) 3/16 inch
b) 3/8 inch
c) 5/16 inch
d) ¼ inch
Solution:
t=
pD (120 psi )(30 inches )
=
= 0.225 inch ≈ 1 / 4 inch
2 St
2 (8000 psi )
44. A 50.8-mm solid shaft is driven by a 36-tooth gear and transmits power at 120 rpm. If the allowable shearing stress is 83 MPa. Determine the power
transmitted, in Hp.
a) 36 Hp
b) 28 Hp
c) 42 Hp
d) 38 Hp
Solution:
T=
(
)
π D 3 s s π (50.8 mm )3 83 N / mm 2
=
= 2 136 461.415 N ⋅ mm
16
16
7
MACHINE DESIGN/SHOP PRACTICE
P=
π n T π (120 )(2.14 )
=
= 26.89 kW = 36.05 Hp
30
30
45. A helical spring having squared and ground ends has a total of 18 coils and its material has modulus of elasticity in shear of 78.91 GPa. If the spring
has an outside diameter of 10.42 cm and a wire diameter of 0.625 cm, compute the deflection in the spring due to a load of 50 kg.
a) 490 mm
b) 409 mm
c) 390 mm
d) 309 mm
δ=
Solution:
8F(D w )3 N a
G (d w )4
=
8FC 3 N a
Gd w
Where, for S & G ends:
D m D o − d w 10.42 − 0.625
=
=
= 15.672
dw
dw
0.625
C=
δ=
N a = N − 2 = 18 − 2 = 16 coils
8 (50 kg )(9.8066 N / kg )(15.672 )3 (16 )
(78 910 N / mm )(6.25 mm)
2
= 489.85 mm
46. With the electric arc welding rate of 18 in/min, how long will it takes to weld a 0.5 inch thick plate by 3 ft long seam?
a) 1.5 minutes
b) 3 minutes
c) 2 minutes
d) 2.5 minutes
Solution:
t=
(3 ft )(12 inches / ft ) = 2 min utes
Length
=
Rate of Welding
18 in / min
47. How long will it take to mill 0.75 inch by 2 inches keyway in a 3 inches diameter shafting with 24-tooth cutter turning at 100 rpm and 0.005” feed per
tooth?
a) 10 seconds
b) 8 seconds
c) 12 seconds
d) 15 seconds
Solution:
t=
2 inches
Length
=
= 0.1667 min
(No. of Teeth / rev)(Feed, inch / tooth )(rpm ) (24 teeth / rev)(0.005 in / tooth )(100 rpm )
o
48. Calculate the tooth thickness of a 14½ spur gear with a pitch of 4.
a) 0.3927 inch
b) 9.975 mm
Solution:
t=
c) 0.9975 cm
d) Any of these
1.5708 1.5708
=
= 0.3927 inch = 9.975 mm = 0.9975 cm
Pd
4
49. A journal bearing with diameter of 76.2 mm is subjected to a load of 4.9 kN while rotating at 200 rpm. If its coefficient of friction is 0.02 and L/D = 2.5,
2
find its projected area, in mm
2
2
2
2
b) 14 516.1 mm
c) 15 416.1 mm
d) 16 416.1 mm
a) 41 516.1 mm
Solution:
L = 2.5 D = (2.5)(76.2) = 190.5 mm
Projected Area,
A = D (L ) = (76.2 mm )(190.2 mm ) = 14 516.1 mm 2
50. Determine the diameter of a line shaft transmitting 12 Hp at 180 rpm with torsional deflection of 0.08 degree per foot length.
a) 2.75 inches
b) 2.34 inches
c) 2.25 inches
d) 3.34 inches
Solution:
⎛P⎞
D = 4.6 ⎜ ⎟
⎝N⎠
0.25
⎛ 12 ⎞
= (4.6 )⎜
⎟
⎝ 180 ⎠
0.25
= 2.34 inches
Where, P = power transmitted, Hp
N = n = rpm of the shaft
6
Note: This equation is for torsional deflection of 0.08 degree per ft length and using G = 12 x 10 psi.
Derived from the equations:
32 T
θ
=
L πD 3 G
and
Hp =
Tn
63 000
51. Calculate the maximum unit shear in a 3-inch diameter steel shaft transmitting 2400 in-lb of torque at 180 rpm.
a) 453 psi
b) 543 psi
c) 435 psi
d) 534 psi
Solution:
ss =
16 T
πD
3
=
(16)(2400) = 452.71 psi
π (3)3
52. The shaft whose torque varies from 2000 to 6000 in-lb has 1.5 inches in diameter and 60000 psi yield strength. Determine the shaft mean or average
stress.
a) 6 036.10 psi
b) 6306.10 psi
c) 3 018.05 psi
d) 9 054.15 psi
Solution:
s min =
16Tmin 16 (2000 )
=
= 3018.05 psi
π D3
π (1.5)3
s max =
8
16Tmax 16 (6000 )
=
= 9054.15 psi
π D3
π (1.5)3
MACHINE DESIGN/SHOP PRACTICE
sm =
s min + s max 3018.05 + 9054.15
=
= 6036.10 psi
2
2
53. An open belt drive connects a 450 mm diameter driving pulley to another driven pulley 1000 mm in diameter. The belt is 300 mm wide and 10 mm thick.
The coefficient of friction of the belt drive is 0.30 and the mass of the belt is 2.8 kg/m of belt length. Other data are as follows: center distance between
shafts, 4 m; maximum allowable tensile stress on the belt, 1500 kPa; and speed of driving pulley, 900 rpm. Calculate the maximum power that can be
transmitted, in kW.
a) 40.82 kW
b) 42.80 kW
c) 48.20 kW
d) 28.40 kW
Solution:
P=
⎛ ef θ − 1 ⎞
Ft = F1 − F2 = (F1 − Fc )⎜⎜ fθ ⎟⎟
⎠
⎝ e
F1 − Fc
= e fθ
F2 − Fc
π n1 T1 ⎛ π n ⎞
⎛D ⎞
=⎜
⎟ (Ft )⎜ 1 ⎟
30
30
⎝ 2 ⎠
⎠
⎝
π D1 n1 π (0.450 )(900 )
=
= 21.21 m / s
60
60
⎛ 1000 − 450 ⎞
⎛ D − D1 ⎞
⎟⎟ = 3.0041 radians
θ = θ1 = π − ⎜ 2
⎟ = π − ⎜⎜
C
⎝
⎠
⎝ 4 000 ⎠
F1
V=
Belt speed,
Wrap angle,
Belt tension ratio,
F1 − Fc
= e fθ = e (0.30 )(3.0041) = 2.463
F2 − Fc
Centrifugal Force,
⎛ 2.8 kg / m ⎞
⎟⎟ (b t )(21.21 m / s )2 = 1259.62 N
Fc = ρ bt V 2 = ⎜⎜
b
t
⎝
⎠
Maximum belt tension, F1
(
θ
F2
)
= s t A = s t b t = 1 500 000 N / m 2 (0.30 m )(0.01 m ) = 4500 N
⎛ e fθ − 1 ⎞
⎛ 1.463 ⎞
Ft = (F1 − Fc ) ⎜⎜ fθ ⎟⎟ = (4500 − 1259.62 )⎜
⎟ = 1924.76 N
e
⎝ 2.463 ⎠
⎠
⎝
⎛ 0.45 ⎞
⎛ π n1 ⎞ ⎛ D1 ⎞ ⎛ π (900 ) ⎞
Power to be transmitted, P = ⎜
⎟ Ft ⎜
⎟=⎜
⎟(1924.76 )⎜
⎟ = 40 815.98 W = 40.82 kW
30
2
30
⎠ ⎝
⎠
⎝ 2 ⎠
⎝
⎠ ⎝
Belt Net Tension,
54. There are three parallel shafts A, B, and C. Shaft A has 24 teeth gear of Pd = 4 meshing with a larger gear on shaft B having 70 teeth. A smaller gear,
20 teeth and pitch of 3, on shaft B meshes with 50 teeth gear on shaft C. Find the torque on shaft C if the input Hp to shaft A is 50 Hp turning at 1200
rpm, and the efficiency of each gear combination is 98 %.
a) 1532 ft-lb
b) 1352 ft-lb
c) 1253 ft-lb
d) 1325 ft-lb
Solution: T1 = 24 teeth
T2 = 70 teeth
n1 T2 x T4
=
n 4 T1 x T3
T3 = 20 teeth
A
T4 = 50 teeth
⎛ T ⎞⎛ T ⎞
⎛ 24 ⎞⎛ 20 ⎞
n 4 = n1 ⎜⎜ 1 ⎟⎟⎜⎜ 3 ⎟⎟ = (1200 )⎜ ⎟⎜ ⎟ = 164.57 rpm
T
T
⎝ 70 ⎠⎝ 50 ⎠
⎝ 2 ⎠⎝ 4 ⎠
Hp o = Hp (e ) = (50 )(0.98)(0.98) = 48.02
TC =
1
B
C
2
3
4
63000Hp o (63 000 )(48.02 )
=
= 18 382.82 in ⋅ lb = 1531.90 ft ⋅ lb
nC
164.57
55. A flywheel weighing 450 kg has a radius of 375 mm. How much energy, in N-m, does the flywheel loss from 180 rpm to 168 rpm?
a) 1472.33
b) 1541.33
c) 1451.33
d) 1433.51
Solution:
⎛ 180 ⎞
V1 = 2πRN 1 / 60 = 2π (0.375) ⎜
⎟ = 7.069 m / s
⎝ 60 ⎠
∆KE =
(
)
[
⎛ 168 ⎞
V2 = 2πRN 2 / 60 = 2π (0.375)⎜
⎟ = 6.597 m / s
⎝ 60 ⎠
]
m V12 − V22
450 (7.069 )2 − (6.597 )2
=
= 1451.33 N ⋅ m
2
2
56. A punch punches 1-in diameter hole in a steel plate ¾ inch thick every 10 sec. The actual punching takes 1 sec. The ultimate shear strength of the
2
plate is 60,000 psi. The flywheel of the punch press has a mass moment of inertia of 500 in-lb-sec and rotates at a mean speed of 150 rpm. What is
the speed fluctuation, in rpm?
a) 65.4 rpm
b) 64.5 rpm
c) 6.749 rpm
d) 67.49 rpm
(
)
⎛ ω + ω2
⎛1⎞
⎛1⎞
∆KE = ⎜ ⎟ I ω12 − ω12 = ⎜ ⎟ I (ω1 − ω 2 )(ω1 + ω 2 ) = I (ω1 − ω 2 ) ⎜⎜ 1
2
2
2
⎝ ⎠
⎝ ⎠
⎝
2πN 2π (150 )
=
= 15.71 rad / s
Mean angular velocity, ω =
60
60
Punching Force, F = s u (πdt ) = (60 000 )(π )(1)(0.75) = 141 371.67 lb
Solution:
9
⎞
⎟⎟ = I (ω1 − ω) ω
⎠
MACHINE DESIGN/SHOP PRACTICE
Kinetic Energy,
∆KE = 1
Speed Fluctuation,
2
(F) t = (1 2 )(141 371.67 ) ⎛⎜ 0.75 ⎞⎟ = 4417.86 ft ⋅ lb
(ω1 − ω 2 ) = ∆KE =
Iω
⎝ 12 ⎠
(4417.86 ft ⋅ lb)(12)
(500 in ⋅ lb ⋅ s )(15.71) = 6.749 rad / s = 64.5 rpm
2
57. Determine the maximum shear stress induced on a 1.5-inch diameter solid shaft loaded with a torque of 8,000 in-lb and a bending moment of 12,000
in-lb.
a) 21 763.5 psi
b) 27 163.5 psi
c) 23 761.5 psi
d) 26 173.5 psi
s s max =
Solution:
16
πD
3
M2 + T2 =
16
π (1.5)3
(12 000)2 + (8 000)2
= 21 763.5 psi
58. A 75 mm shaft is transmitting 300 kW at 600 rpm. A solid coupling has 6 bolts and each 18 mm in diameter. Find the required bolt circle diameter if the
bolt shearing stress is 27.5 MPa.
a) 227.4 mm
b) 233.6 mm
c) 254.5 mm
d) 272.6 mm
Solution:
T=
30 P (30 )(300 )
=
= 4.775 kN ⋅ m
πn
π (600 )
DB =
8T
π d ss n B
2
=
8 (4 775 000 N ⋅ mm )
(
)
π (18 mm )2 27.5 N / mm 2 (6 )
= 227.4 mm
59. To finally complete milling (finishing) work of steel material, the operator has the option to choose the better available cutter in stock and these are: both
1.5 inches diameter; high speed steel with recommended cutting speed of 90 fpm; carbide tipped with cutting speed of 300 fpm. Compute the rpm of
the cutter.
a) 764
b) 376
c) 673
d) 746
Solution:
n=
300 fpm
V
= 763.94 rpm
=
πD
⎛ 1.5 ⎞
ft ⎟
π⎜
⎝ 12 ⎠
60. It is the peak of the stress-strain curve and sometimes simply called as tensile strength. How do you call this?
a) Yield strength
b) Ultimate tensile strength
c) Endurance strength
d) Elastic strength
61. It is a synergistic collection of machine elements. It is synergistic because as a design it represents an idea or concept greater than the sum of the
individual parts. How do you call this?
a) Synthesis
b) Analysis
c) Mechanical system
d) Concurrent engineering
62. How do you call the ratio of stress and strain?
a) Modulus of rigidity
b) Modulus of resilience
d) Modulus of elasticity
d) Modulus of stiffness
63. What is the philosophy of involving many disciplines from the beginning of a design effort and keeping them involved throughout product development?
a) Synthesis
b) Design
c) Mechanical system
d) Concurrent engineering
64. It is one of the design stages that may be found desirable to use field experience as a basis for further improvement of the product. Since the final
product is available, it often becomes the model for evaluation during this design process. This statge is not always used in the design process. How do
you call this?
a) Detail stage
b) Revision stage
c) Preliminary stage
d) Feasibility stage
65. That portion of the stress-strain diagram where there is a large increase in strain with little or no increase in stress is called as:
a) Yield strength
b) Ultimate tensile strength
c) Endurance strength
d) Elastic strength
66. This is the first stage of design processes that determines whether it is both possible and profitable to undertake a given engineering project. The ideas
generated during this stage of the design process generally consist of general statements about overall concepts rather than specific descriptions of
hardware. How do you call this?
a) Detail stage
b) Revision stage
c) Preliminary stage
d) Feasibility stage
67. At this point in the stress-strain curve, the material experiences some amount of plastic strain and thus will not return to its original shape after release
of the load.
a) Elastic limit
b) Proportional limit
c) Endurance limit
d) Yield point
68. This type of load is the one that is applied slowly and never removed. How do you call this load?
a) Static load
b) Fluctuating load
c) Random load
d) Fluctuating load
69. At the highest point of the stress-strain curve during the test, what highest stress on a test bar of the material is measured?
a) Apparent stress
b) Ultimate stress
c) Elastic stress
d) Yield stress
70. This is a stress when a given element of a load-carrying member is subjected to a certain level of tensile stress followed by the same level of
compressive stress; the stress cycle is repeated many thousands of times. How do you call this type of stress?
a) Repeated and Reversed Stress
b) Static stress
c) Minimum stress
d) Maximum stress
71. These steels contain 30 to 50 points of carbon (0.30%-0.50%). Most machine elements having moderate to high strength requirements with fairly good
ductility and moderate hardness requirements come from this group.
a) High-carbon steels
b) Medium-carbon steels
c) Low-carbon steels
d) Alloy steels
72. It is the process of increasing the hardness and strength of ductile material as it is plastically performed. How do you call this process?
a) Strain hardening
b) Surface hardening
c) Cold hardening
d) Hot hardening
73. Which of the following the average density of a leather belts?
3
3
b) 0.253 lb/in
a) 0.035 lb/in
c) 0.046 lb/in
10
3
d) 0.074 lb/in
3
MACHINE DESIGN/SHOP PRACTICE
74. As a flat belt drive designer, what must be the belt speed to make your design most economical?
a) 4000 to 4500 fpm
b) 2000 to 3000 fpm
c) 3000 to 4000 fpm
d) 4000 to 5000 fpm
75. As suggested by Taylor, what is the recommended initial tension of belt,?
a) 75 lb/in of width
b) 71 lb/in of width
c) 73 lb/in of width
d) 80 lb/in of width
76. Not adaptable to welding due to low tensile strength and poor ductility etc.
a) copper parts
b) aluminum parts
c) cast iron materials
d) bronze parts
77. Bearing surface that completely surrounds the journal is also called:
a) offset bearing
b) centrally loaded bearing
c) full bearing
d) babbit bearing
78. The purpose of lubrication is as mentioned except:
a) to lighten the load
b) prevent adhesion
d) cool the moving elements
c) prevent corrosion/oxidation
79. Tools usually used in wood pattern making in foundry shop.
a) saws and chisel
b) knives and drills
c) band saw
d) drill machine
80. This group of materials characterizes the high level of corrosion resistance offered by alloys in this group. To be classified on this group of material, the
alloy must have a chromium con tent of at least 10%, and most have 12% to 18% chromium.
a) Stainless steels
b) Structural steels
c) Tool steels
d) Mild steels
81. The ability of the material to absorb energy up to fracture.
a) Toughness
b) Rigidity
c) Resilience
d) Stiffness
82. These group of stainless steels fall into the AISI 200 and 300 series. They are general-purpose grades with moderate strength. Most are not heattreatable, and their final properties are determined by the amount of working, with the resulting temper referred to as 1/4 hard, ½ hard, 3/4 hard, and full
hard. These alloys are nonmagnetic and are typically used in food processing equipment.
a) Austenitic stainless steels
b) Ferritic stainless steels
c) Martensitic stainless steels
d) None of these
83. These stainless steels belong to the AISI 400 series, designated as 405, 409, 430, 446, and so on. They are magnetic and perform well at elevated
temperatures, from 1300°F to 1900°F (700°C-1040°C), depending on the alloy. They are not heat-treatable, but they can be cold-worked to improve
properties. Typical applications include heat exchanger tubing, petroleum refining equipment, automotive trim, furnace parts, and chemical equipment.
a) Austenitic stainless steels
b) Ferritic stainless steels
c) Martensitic stainless steels
d) None of these
84. These stainless steels are also members of the AISI 400 series, including 403, 410, 414, 416, 420, 431, and 440 types. They are magnetic, can be
heat-treated, and have higher strength than the 200 and 300 series, while retaining good toughness. Typical uses include turbine engine parts, cutlery,
.scissors, pump parts, valve parts, surgical instruments, aircraft fittings, and marine hardware.
a) Austenitic stainless steels
b) Ferritic stainless steels
c) Martensitic stainless steels
d) None of these
85. Most of these materials are designated by ASTM numbers established by the American Society for Tesfing and Materials. One common grade is ASTM
A36, which has a minimum yield point of 36 000 psi (248 MPa) and is very ductile. It is basically a low-carbon, hot-rolled steel available in sheet, plate,
bar, and structural shapes such as some wide-flange beams, American Standard beams, channels, and angles.
a) Structural steels
b) Tool steels
c) Cast steels
d) Stainless steels
86. Compounds of metallic elements, most frequently oxides, nitrides, and carbides.
a) Plastic
b) Polymers
c) Ceramics
d) Alloy
87. This material refers to a group of steels typically used for cutting tools, punches, dies, shearing blades, chisels, and similar uses. The numerous
varieties of tool steel materials have been classified into seven general types. Whereas most uses of these steels are related to the field of
manufacturing engineering, they are also pertinent to machine design where the ability to maintain a keen edge under abrasive conditions is required.
Also, some of these steels have rather high shock resistance which may be desirable in machine components such as parts for mechanical clutches,
pawls, blades, guides for moving materials, and clamps.
a) Structural steels
b) Tool steels
c) Cast steels
d) Stainless steels
88. A material having different properties in all directions at point in solid.
a) Isotropic material
b) Anisotropic material
c) Orthotropic material
d) Ceramic material
89. Parts subjected to repeated applications of loads or to stress conditions that vary with time over several thousands or millions of cycles fail because of
the phenomenon of fatigue. Materials are tested under controlled cyclic loading to determine their ability to resist such repeated loads. The resulting
data are reported as which of the following?
a) Endurance strength
b) Ultimate strength
c) Yield strength
d) Elastic strength
90. Which of the following is the other term for endurance strength?
a) Fatigue strength
b) Ultimate strength
c) Yield strength
d) Elastic strength
91. A material having different properties in three mutually perpendicular directions at point in solid and having three mutually perpendicular planes of
material symmetry.
a) Orthotropic material
b) Isotropic material
c) Anisotropic material
d) Thermoplastic material
92. The combinations of two or more materials, usually consisting of fiber and thermosetting polymer.
a) Brittle materials
b) Composite materials
c) Polymers
93. Endurance strength is 100% for a component with :
A. ground finish
B. mirror finish
C. machined surface
94. Which one of the following is a finishing process?
11
d) Ceramics
D. hot rolled surface
MACHINE DESIGN/SHOP PRACTICE
a) Rolling
b) Forging
95. Wrought iron contains a maximum of which of the following?
a) 0.01 % carbon
b) 0.3 % carbon
96. Pig iron is produced by reduction of iron ore in a:
a) Cupola
b) Bessemer converter
c) Sintering
d) Engraving
c) 0.6 % carbon
d) 2.0 % carbon
c) Open hearth furnace
d) Blast furnace
97. Which of the following are the main alloying elements present in stainless steel?
a) Nickel and manganese
b) Nickel and tungsten
c) Nickel and chromium
98. Along with chromium and vanadium the main constituent of high speed steel is which of the following?
a) Manganese
b) Nickel
c) Tungsten
99. Grey cast iron gives grey fracture due to the presence of which of the following?
a) Ferrite
b) Pearlite
c) Graphite
100. Copper is the parent metal of brass. Which of the following is the other metal present in brass?
a) Lead
b) Tin
c) Aluminum
101. Gun metal contains 5 to 10 percent of which of the following materials?
a) Zinc
b) Lead
c) Tin
102. The accuracy of the following instrument is maximum:
a) Steel scale
b) Vernier caliper
c) Vernier dial gauge
103. The process of joining two slip gauges for precision measurement is known as:
a) Wringing
b) Sliding
c) Slipping
d) Nickel and cobalt
d) Vanadium
d) Cementite
d) Zinc
d) Aluminum
d) Optical projector
d) Cohesion
104. Which of the following is not a hand cutting tool?
a) Band saw
b) Rip saw
c) Tenon saw
d) Dovetail saw
105. Which of the following is not a boring tool?
a) Bradawl
b) C-clamp
c) Auger
d) Gimlet
106. The working temperature range for soldering process is:
o
o
o
o
o
o
o
o
b) 180 C to 250 C c) 220 C to 300 C
d) 350 C to 480 C
a) 60 C to 120 C
107. Zinc chloride is used as flux in the following process.
a) Soft soldering
b) Brazing
c) Welding
d) Trepanning
108. During a resistance welding process, the pressure is released:
a) As soon as the flow of current starts
b) Immediately after the current supply c) During heating process
d) After the weld cools
109. Seam welding is used:
a) To form mesh
b) For continuous welding operation
c) For welding thick components
d) For multisport welding purpose
110. Forge welding is mainly used for welding which of the following?
a) Cast iron
b) Wrought iron
c) High carbon steel d) Stainless steel
111. The commonly used gases in tungsten arc welding are:
a) Hydrogen and oxygen
b) Hydrogen and argon
c) Hydrogen and helium
d) Helium and argon
112. In an arc process, arc length should be equal to which of the following?
a) The electrode diameter
b) Haft the electrode diameter
c) Twice the electrode diameter
d) Twice the thickness of the work-piece
113. Large gears, machine structures, brackets, linkage parts, and other important machine parts are made from this material. The several types of grades
available span wide ranges of strength, ductility, machinability, wear resistance, and cost. These features are attractive in many applications. How do
you call this material?
a) Structural steel
b) Tool steel
c) Cast steel
d) Stainless steel
114. A pair of flanges fitting on the ends of pipes by bolts to hold the pipes together is known as:
a) Nipple
b) Socket
c) Union
d) Ferrule
115. A short piece of pipe threaded at both ends to join pipe fittings in threaded joint is known as:
a) Nipple
b) Socket
c) Union
d) Nozzle
116. This steel refers to a group of steels typically used for cutting tools, punches, dies, shearing blades, chisels, and similar uses.
a) Stainless Steel
b) Wrought steel
c) Structural steel
d) Tool steel
117. It is called as the fourth most commonly used metal in the world.
a) Zinc
b) Steel
c) Iron
d) Aluminium
118. This is a family of alloys of copper and zinc, with the content of zinc ranging from about 5% to 40%. It is often used in marine applications because of
its resistance to corrosion in salt water. How do you call this?
a) Brass
b) Copper
c) Bronze
d) Gold
119. This cast alloy is actually a high-strength form of brass because it contains zinc, the characteristic alloying element of the brass family. It contains
copper, zinc, tin, and manganese. What do you call this material?
a) Manganese bronze
b) Aluminum bronze
c) Nickel tin bronze
d) Tin bronze
120. A spring material with high tensile strength and corrosion resistance; it has superior creep resistant properties at higher temperatures; and it can be
o
used up to 550 F and subzero temperatures.
a) Music wire
b) Oil-tempered wire
c) Stainless steel 302
d) Plain-carbon steel 1095
121. A spring material that has good corrosion resistance and electrical conductivity, and is frequently used for contact fingers in switches.
a) Music wire
b) Piano wire
c) Phosphor bronze
d) Oil-tempered wire
122. A material that has an increasing use in spring because of its many desirable qualities such as good impact resistance, freedom from decarburisation
and surface defects, and relatively low cost.
a) Stainless steel 302
b) Silicon-manganese steel 9262
c) Chromium-vanadium steel 6150
d) Chromium-nickel-molybdenum steel 8660
123. It is a general-purpose spring steel used for many types of coil springs where the cost of music wire is prohibitive and in sizes larger than available in
music wire. This is not suitable for shock or impact loading.
a) Chrome silicon
b) Chrome vanadium
c) hard-drawn wire
d) Oil-tempered wire
124. This alloy is an excellent material for highly stressed springs that require long life and are subjected to shock loading. It has a common Rockwell
o
hardness ranging from C50 to C53 and this may be used to a temperature up to 250 C.
a) Chrome silicon
b) Chrome vanadium
c) hard-drawn wire
d) Piano wire
12
MACHINE DESIGN/SHOP PRACTICE
125. Polymers with intermediate amount of cross-linking.
a) Elastomers
b) Ceramics
c) Polymers
126. The stress at time of fracture or rupture is called as:
a) Ultimate stress
b) Fracture stress
c) Yield stress
127. The compounds of metallic and non-metallic elements with no crystal structure.
a) Elastomers
b) Ceramics
c) Polymers
128. A material having properties not function of position in solid is known as:
a) Homogeneous material
b) Ductile material
c) Brittle material
129. What is the wire rope where wires and strands are twisted in same direction?
a) Long lay
b) Lang lay
c) Performed
130. These wire ropes used for haulages, rigging, guard rails, etc. How do you call these wire ropes?
a) 6 x 35 IWRC
b) 6 x 25 IWRC
c) 7 x 8 IWRC
131. This wire rope is called as the general purpose rope, how do you designate this rope?
a) 6 x 19 IWRC
b) 6 x 21 IWRC
c) 6 x 19 IWRC
132. Which of the following the average density of a leather belts?
3
3
3
b) 0.253 lb/in
c) 0.046 lb/in
a) 0.035 lb/in
133. What is the breaking strength of oak-tanned belting?
a) 2 to 5 ksi
b) 4 to 7 ksi
c) 3 to 6 ksi
13
d) Astronomers
d) Fatigue stress
d) Glasses
d) Composite material
d) Non-performed
d) 7 x 7 IWRC
d) 7 x 26 IWRC
d) 0.074 lb/in
d) 5 to 8 ksi
3
MACHINE DESIGN/SHOP PRACTICE
JCSF ENGINEERING REVIEW CENTER
# 2 Alvaran’s Apartment, Purok 7, Halang
City of Calamba, Laguna
MACHINE DESIGN AND SHOP PRACTICE
(Refreshers Trivia # 14 for September 2012 Board Examination)
Prepared by: Jose R. Francisco, PME
September 2012
MULTIPLE CHOICE QUESTIONS
Select the best answer from each of the following questions. On the answer sheet provided, shade the box that corresponds to your choice. Strictly no
erasures allowed.
1.
A multi-storey commercial building has a total of 1200 occupants, determine the number of elevator to be installed as a requirement to serve the
building occupants.
a) 3 elevators
b) 5 elevators
c) 6 elevators
d) 4 elevators
Solution:
Number of Elevators =
Number of Occupants 1200
=
= 5.45 ≈ 6 elevators
220
220
Note: There shall be one elevator per 220 persons occupying building other than first floor.
2.
2
If a multi-story building has a floor area of 8250 m other than the first floor, determine the number of passenger elevator to be installed as a
requirement to serve the building occupants.
a) 3 elevators
b) 5 elevators
c) 6 elevators
d) 4 elevators
Solution:
Floor Area 8 250
=
= 887
9.3
9.3
Number of Occupants 887
Number of Elevators =
=
= 4 elevators
220
220
No. of Occupants =
2
Note: By Floor area, 9.3 m of floor area is average density of occupancy per person.
3.
4.
5.
6.
7.
8.
_______ is the process of shaving off small amounts of metal using hand-held tools. This process is most often done to obtain precision alignment of
machine parts; it is also done to provide shallow pockets that will hold lubricants on flat surfaces, such as machine ways.
a) Drilling
b) Scraping
c) Reaming
d) Milling
________ means putting the parts of something together.
a) Laying out
b) Assembling
c) Installing
d) Fabricating
_________ are tools used to turn, or drive, screws; made in may sizes and several shapes; the size is measured by the length of the blade, which is
made of tool steel that is hardened and tempered. The screwdriver point for driving slotted screws should be correctly shaped; it must be fit the slot in
the screw.
a) Wrenches
b) Hammers
c) Screw drivers
d) Scrapers
A place in which metal parts are cut to the size required and put together to form mechanical units of machines, the machine so made to be used
directly or indirectly in the production of the necessities and luxuries of civilization.
a. Welding shop
b. Junk shop
c. Machine shop
c) Flower shop
A metal-turning machine tool in which the work, while revolving on a horizontal axis, is acted upon by a cutting tool which is made to move slowly (feed)
in a direction more or less parallel to the axis of the work (longitudinal feed), or in a direction of right angles to the axis of work (cross feed).
a. Grinding machine
b. B. Milling machine
c. Lathe machine
d. Drilling machine
This screw driver has a bent handle; it is used where a straight screwdriver will not reach.
a) Offset screw driver
b) Phillips screw driver
c) Mechanical screw driver
d) Mill screw driver
9.
A machine tool used mainly for producing holes in metal.
a. Reaming machine
b. Drill press
c. Welding machine
d. Boring machine
10. __________ are tools used for cutting small wire and for holding, twisting, turning, pulling, and pushing.
a) Screw drivers
b) Wrenches
c) Pliers
d) Hammers
11. A machine which is ordinarily used for finishing flat or partly curved surfaces of metal pieces few in number and not usually over a foot or too long.
a. Shaper machine
b. Planer machine
c. Milling machine
d. Grinding machine
12. A machine tool in which an abrasive wheel is used as a cutting tool to obtain a very high degree of accuracy and a smooth finish on metal parts,
including soft and hardened steel.
a. Drilling machine
b. Milling machine
c. Grinding machine
d. Welding machine
13. A file which is thick, rectangular-shaped file with parallel edges.
a. Hand file
b. Pillar file
c. Mill file
d. Half-moon file
14. A file which is tapered in thickness and of uniform width. This is used for filing slots and keyways.
a. Pillar file
b. Hand file
c. Mill file
d. Half-moon file
15. ________ also known as combination pliers, are used for gripping; can also cut small-size wire; the slip-joint makes it possible to grip large parts.
a) Slip-joint pliers
b) Side cutting pliers
c) Round nose pliers
d) Long nose pliers
16. Which of the following is not belong to standard shapes of file?
a. flat
b. half-round
c. three-square
d. none of these
17. One of the three basic ways of using a file which is done by pushing the file lengthwise, straight with or slightly diagonal to the workpiece.
1
MACHINE DESIGN/SHOP PRACTICE
a. Lathe filing
b. Draw filing
c. Straight filing
d. Back filing
18. One of the three basic ways of using a file which consists of stroking the file against the revolving workpiece held in the lathe.
a. Lathe filing
b. Straight filing
c. Draw filing
d. Mill filing
19. One of the three basic ways of using a file which is performed by grasping the file at end and pushing and drawing across the workpiece.
a. Draw filing
b. Lathe filing
c. Straight filing
d. None of the above
20. A hand tool which is commonly used for cutting or twisting wire and chipping small parts and not to be used for tightening or loosening bolts and nuts.
a. Screwdriver
b. Wrench
c. Pliers
d. None of the above
21. A type of pliers which is used for cutting wires and holding flat round stock.
a. Long-nose pliers
b. Side-cutting pliers
c. Slip joint combination pliers or mechanical pliers
d. Square pliers
22. A type of pliers which is used in electrical works for cutting heavy or light wires or for cutting small nails.
a. Side-cutting pliers
b. Long-nose pliers
c. Mechanical pliers
d. None of the above
23. A type of pliers which is used for cutting and holding fine wire. This is also useful in reaching tight places.
a. Long-nose pliers
b. Slide-cutting pliers
c. Diagonal pliers
d. None of the above
24. Which of the following is a primary forming process?
a) Casting
b) Turning
c) Fitting
d) Buffing
25. Which of the following is not a machining process?
a) Turning
b) Milling
c) Casting
d) Grinding
26. The joints produced by this method are as strong as the parent metal.
a) Soldering
b) Brazing
c) Riveting
d) Welding
27. Which one of the following is a finishing process?
a) Rolling
b) Forging
c) Sintering
d) Engraving
28. Which of the following process affects the changes in properties of materials?
a) Shaping
b) Hardening
c) Sintering
d) Anodizing
29. The system used for mass production of identical parts within specified limits of sizes for selection of components at random is known as:
a) Simplification
b) Standardization
c) Interchangeable system
d) Automation
30. Alloys are extensively used in industry because they are:
a) Sufficiently soft
b) Have good strength
c) Malleable
d) Ductile
31. Which of the following is the most abundantly used material in industry?
a) Cast iron
b) Mild steel
c) Medium carbon steel
d) High carbon steel
32. Wrought iron contains a maximum of which of the following?
a) 0.01 % carbon
b) 0.3 % carbon
c) 0.6 % carbon
d) 2.0 % carbon
33. Pig iron is produced by reduction of iron ore in a:
a) Cupola
b) Bessemer converter
c) Open hearth furnace
d) Blast furnace
34. Which of the following are the main alloying elements present in stainless steel?
a) Nickel and manganese
b) Nickel and tungsten
c) Nickel and chromium
d) Nickel and cobalt
35. Along with chromium and vanadium the main constituent of high speed steel is which of the following?
a) Manganese
b) Nickel
c) Tungsten
d) Vanadium
36. Grey cast iron gives grey fracture due to the presence of which of the following?
a) Ferrite
b) Pearlite
c) Graphite
d) Cementite
37. Copper is the parent metal of brass. Which of the following is the other metal present in brass?
a) Lead
b) Tin
c) Aluminum
d) Zinc
38. Gun metal contains 5 to 10 percent of which of the following materials?
a) Zinc
b) Lead
c) Tin
d) Aluminum
39. Y-alloy is an alloy of aluminum and which of the following metals?
a) Manganese
b) Iron
c) Tin
d) Copper
40. Inconel contains 80 % nickel and 14 % chromium. The other metal present in inconel is:
a) Iron
b) Vanadium
c) Silver
d) Tin
41. Monel contains mainly with traces of iron and manganese. The main alloying element of monel is:
a) Aluminum
b) Copper
c) Zinc
d) Lead
42. Bearing materials should posses which of the following?
a) High tensile strength
b) High hardness
c) Hard core
d) High compressive strength
43. Which of the following is the trade name of polypropylene?
a) Alkane
b) Polyprex
c) Styrene
d) Durite
44. The following instrument can be used for subscribing lines parallel to the edges of a part:
a) Vernier caliper
b) Ordinary scale
c) Hermaphordite caliper
d) Combination set
45. Which of the following is the use of surface gauge?
a) Laying out the work accuracy b) Check flatness of surface
c) Checking surface finish
d) Leveling the machine tools
46. The thickness of a thin sheet can be accurately checked with the help of:
a) Ordinary scale
b) Micrometer
c) Combination set
d) Caliper
47. V-block is used in mechanical engineering workshop to check which of the following?
a) Straightness of the job
b) Taper on a job
c) Height of a job
d) Cylindrical jobs
48. ________ is a strong tool used for general work in the shop. Its jaws are pointed at such an angle that it can be used in close corners and unhandy
places.
a) Adjustable-end wrench
b) Adjustable S-wrench
c) Monkey wrench
d) Vise-grip wrench
49. A sine bar is specified by:
a) Its total length
b) Diameter of the rollers
c) Its weight
d) Center to center distance between the rollers
50. _____________ is a handy tool. It works in close places and the strong steel jaws lock to the work and will not slip; it acts like a vise, clamp, plier, pipe
wrench, open-end wrench, or locking tool.
a) Adjustable-end wrench
b) Adjustable S-wrench
c) Monkey wrench
d) Vise-grip wrench
51. A ratchet screw is provided on a micrometer screw gauge to:
a) Lock the measured reading
b) maintain constant measuring pressure for all readings
c) Prevent wearing of screw threads
d) Allow zero adjustments
52. ____________ is a machine for pressing parts of machinery together or forcing them apart, such as pressing a shaft in or out of a pulley or gear
a) Arbor press
b) Drill press
c) Milling machine
d) Forging machine
53. Adjusting nut is provided on a micrometer screw gauge to:
2
MACHINE DESIGN/SHOP PRACTICE
a) Allow zero adjustment
b) Compensate for wear and tear between screw and nut
c) Eliminate backlash
d) Maintain constant measuring pressure for all readings
54. External taper of a job can be measured accurately with help of:
a) Sine bar and slip gauges
b) Sine bar and dial indicator
c) Dial indicator and slip gauges
d) Slip gauges and vernier caliper
55. Internal dovetail taper can be measured by which of the following?
a) Sine bar and slip gauges
b) Balls of standard size and dial indicator
c) Balls of standard size and sine bar
d) Balls of standard size and slip gauges
56. Combination set is used to:
a) Measure long distances
b) Measure cylindrical sizes of a length
c) Measure angles
d) Measure corner radius
57. ____________ are made in many sizes and types are widely used in special work holding fixtures.
a) Toggle clamps
b) C-clamps
c) Spring clamps
d) Spring clamps
58. The measuring accuracy of the following instruments is least.
a) Vernier micrometer
b) Micrometer screw gauge
c) Steel scale
d) Optical projector
59. For filing brass or bronze pieces, the following type of file is preferred.
a) Coarse cut or rough cut file
b) Single cut file
c) Double cut file
d) Second cut file
60. __________ are elements used to hold together metal parts in a form of bolts, screws, pins, and rivets
a) Bolts
b) Screws
c) Fasteners
d) Nuts
61. The cleaning of a file is done by which of the following?
a) Rubbing on wood
b) Using a file card
c) Dipping in dilute-alcohol
d) Dipping in dilute alkali
62. This fastener has a smooth, round head; a back, round finish; and a coarse thread. It is usually used to fasten a wooden part to metal. The square part
under the head sinks into the wood and keeps the bolt from turning while the nut is being tightened.
a) Carriage bolt
b) Tap bolt
c) Cap screw
d) Set screw
63. Thin metal pieces can be cut with saw by:
a) Using saw blade with very fine teeth
b) Projecting the piece on one side of a vice and then cutting
c) Placing several pieces together
d) Placing the piece between two wooden pieces and cutting through the metal and wood
64. During the filing operation, the following precaution must be observed.
a) Do not rub fingers over the work
b) Do not rub fingers over the file
c) Apply equal pressure during forward and backward stroke
d) Clean the file frequently
65. A hacksaw is specified by the following parameter of its blade.
a) Material
b) Thickness
c) Width
d) Distance between two holes at its ends
66. These fasteners are made with heads of several different shapes and are made with either coarse or fine threads; made of steel, stainless steel, or
brass. The smaller diameters are described by gage numbers, 0 – 12. These sizes range from 0.060” to 0.216”. the gage numbers are the same for
both machine screws and wood screws. Larger diameters are usually designated by their sizes: ¼”, 5/8”, and 3/8”.
a) Carriage bolts
b) Machine screws
c) Cap screws
d) Set screws
67. The length of hacksaw blade is measured:
a) From one extreme to another
b) Between centers of two holes at its extremes
c) By the length of cut
d) Between the toothed length
68. Taps are used for which of the following?
a) Cutting accurate square holes b) Finishing the round holes c) Cutting internal threads on jobs
d) Cutting external threads in jobs
69. _________ are often used to fasten metal parts to wood; made with flat, round, or oval heads. The heads are slotted or recessed so they can be turned
with screwdrivers. These screws are made of steel, brass, and aluminum. Steel wood screw come either bright or blued finish, or they are plated with
cadmium, nickel, or chromium to prevent rust or corrosion. The diameter of these screws and machine screws is measured on on the body under the
head with the American Standard Screw gage
a) Wood screws
b) Lag screws
c) Set screw
d) Cap screws
70. These screws are made with heads of several different shapes; usually finished all over and are made with either coarse or fine threads; used when it is
not convenient to get at both sides of the work with wrenches. The head of this screw presses against the top piece and holds the part together.
d) Cap screws
a) Wood screws
b) Lag screws
c) Set screw
71. Scrapers are used for which of the following?
a) Enlarging already drilled holes
b) Increasing roundness of holes
c) Removing burrs from corners
d) Removing convex spots from machined surfaces
72. ________ is sometimes called a lock nut or check nut; thinner than an ordinary nut and is used as a lock to keep another nut from loosening by
vibration. Although the jam nut is usually put on last, the thicker nut may be put on last to make use of the greater strength
a) Jam nut
b) Castle nut
c) Wing nut
d) Self-locking nut
73. Forging possesses the following disadvantage:
a) Steel components can easily be forged
b) Copper and brass is forgeable
c) Cast iron components can be forged
d) Components can be produced to close sizes
74. __________ is part of machinist’s combination set. This protactor can be moved along the rule and locked in any position. The protractor has a flat
base, permitting it to rest squarely on the workpiece.
a) Plate protractor
b) Bevel protractor
c) Dial indicating sinometer angle gage
d) Universal bevel vernier protractor
75. Anvil is used for which of the following?
a) Supporting the work pieces b) Holding the work piece
c) Taking out the job from the forge
d) Giving finish to workpiece
76. Fullers are used for which of the following?
a) Supporting the work pieces
b) Holding the work piece
c) Decreasing the length of the work piece
d) Forming necks or grooves on cross section of a job
77. During the upsetting operation:
a) Cross section of a piece decreases and length increases
b) Cross section of a piece increases and length decreases
c) Extra metals removed from the work piece
d) Components of hexagonal shapes are produced
78. Forging of mild steel is done at about:
o
o
o
o
b) 1050 C
c) 800 C
d) 600 C
a) 1200 C
79. A _________ is a raised impression on the surface of the workpiece produced by two hardened rolls and is usually one of two patterns: diamond or
straight.
a) Groove
b) Part
c) Knurl
d) Thread
80. The process of making bolt heads by forging is known as:
a) Upsetting
b) Drifting
c) Swaging
d) Fullering
81. During forging operation, type of hammer held by the forgsmith’s helper is called as:
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MACHINE DESIGN/SHOP PRACTICE
a) Claw hammer
b) Mallet
c) Sledge hammer
d) Ball pen hammer
82. A type of pliers which is used for cutting medium or fine wires and bending small pieces of soft metals.
a. Long-nose pliers
b. Side-cutting pliers
c. Diagonal pliers
d. Mechanical pliers
83. _________ is a term applied to supeabrassive grinding wheels that refers to the amount of abrasive contained in a unit volume of usable grinding
wheels.
a) Abrasion
b) Concentration
c) Grinding index
d) Grindeability
84. A wrench which is used for heavy-duty works. It assures firm contact on all sides of the bolt head and nut, thereby, lessening the chance of having the
sides get round off.
a. Socket wrench
b. Ratchet wrench
c. Box wrench
d. Open wrench
85. A hand tool which is used for ring nuts with square slots cut on the outside diameter or drilled holes on the outer face.
a. Open end wrench
b. Box wrench
c. Spanner wrench
d. Pipe wrench
86. A hand tool used to cut small stocks to size. This tool consists two essential parts: the frame and the blade.
a. Pliers
b. Hacksaw
c. wrench
d. Hammer
87. The standard number of teeth of a hacksaw for cutting very thin tubing and sheet metal.
a. 32 teeth per inch
b. 24 teeth per inch
c. 18 teeth per inch
d. 12 teeth per inch
88. A hand tool used to cut internal threads.
a. hacksaw
b. die
c. tap
d. Wrench
89. The standard number of teeth of a hacksaw for cutting angle iron, brass, copper and pipe.
a. 14 teeth per inch
b. 18 teeth per inch
c. 32 teeth per inch
d. 24 teeth per inch
90. Which of the following is not a principal part of a lathe machine?
a. headstock
b. tailstock
c. tailstock spindle
d. bed
91. One of the parts of tailstock of a lathe machine.
a. Carriage handwheel
b. rack gear
c. upper casting
d. dead center
92. _____________ is somewhat harder abrasive that aluminum oxide but has a sharper, more friable, and quite brittle crystalline structure. It works well
on cast iron and non ferrous materials such as aluminum and copper –based alloys.
a) Fused aluminum oxide
b) Ceramic Aluminum oxide
c) Silicon Carbide
d) Cubic boron nitride
93. The drill that is used to make the hole before tapping.
a. toolbit
b. drill bit
c. tap drill
d. bit drill
94. The process of cutting internal threads.
a. reaming
b. drilling
c. boring
d. tapping
95. A type of wrench which especially designed for allen-head screws only.
a. box wrench
b. open-end wrench
c. allen wrench
d. Monkey wrench
96. The various marking tools used in sheet metal works are:
a) Try square, wing compass, divider and vernier caliper
b) V-block, slip gauges, wing compass and sine bar
c) Sine bar dial indicator and combination set
d) Height gauge, combination set and optical comparator
97. A half-moon stake is used for:
a) Bending, holding and supporting the components
b) Making conical components
c) Working edges on discs
d) Forming pipes and hollow cylindrical surfaces
98. A tunnel stake is used for:
a) Bending, holding and supporting the components
b) Making conical components
c) Working edges on discs
d) Forming pipes and hollow cylindrical surfaces
99. __________ are used to lock a nut or screw in place, thus preventing movement or loosening due to vibration. The helical spring type lock washer
looks like a coil from spring.; they are hardened and tempered, and are used under a screw or nut.
a) Lock washers
b) Plain washers
c) Tooth-type lock washer
d) Square washers
100. Plain butt welding process is used for welding plates approximately up to:
a) 10-mm thickness
b) 25-mm thickness
c) 50-mm thickness
d) 100-mm thickness
101. ___________ are straight-fluted, with two, three, or four flutes depending on the size of the tap. Cutting edges are ground at an angle to the centerline
of the tap; the angular cutting edges cause the chips to shoot ahead of the tap. Plug-type gun taps are designated for tapping open, or through, holes.
Bottoming-type gun taps are designed for tapping blind holes (holes that go only part-way into work piece), producing fine chips that can readily
escape.
a) Gun taps
b) Serial taps
c) Thread forming taps
d) Hand taps
102. The following process is preferred for welding non-ferrous metals:
a) AC high frequency
b) AC normal frequency
c) DC method
d) AC low frequency
103. The commonly used gases in tungsten arc welding are:
a) Hydrogen and oxygen
b) Hydrogen and argon
c) Hydrogen and helium
d) Helium and argon
104. In an arc welding process, metal is deposited on the work piece from the electrode:
a) By force across the arc
b) By gravity
c) Due to attraction of the work piece
d) Due to electromagnetic action
105. Which of the following is the tool used for making holes in red hot jobs?
a) Drill
b) Punch
c) Hardie
d) Chisel
106. It is a process of welding by local fusion with or without the use of a filler. It is the further developed way of welding and was used in building ships in
the world war I.
a) Fusion welding
b) Oxyacetylene welding
c) Resistance welding
d) Shielded metal arc welding
107. In welding GMAW stands for which of the following?
a) Oxyacetylene welding
b) Gas tungsten arc welding
c) Gas metal arc welding
d) Shielded metal arc welding
108. The other term for GMAW
a) SMAW
c) MIG
d) TIG
b) GMAW
109. A type of welding which is an arc welding process which produces a uniting of metals by heating them with an arc between a tungsten (nonconsumable) electrode and the work piece. Shielding of the weld area is obtained from a gas, usually argon or helium
a) Oxyacetylene welding
b) Gas tungsten arc welding
c) Gas metal arc welding
d) Shielded metal arc welding
110. Which of the following is a primary forming process?
a) Casting
b) Turning
c) Fitting
d) Buffing
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