Chapter #3
MCQS+S.Q
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MCQS from board papers:
1.
The shortest distance between two points is called:
a) speed b) acceleration c) distance d) displacement
2. When the values of average and instantaneous velocities are equal, the body is moving with:
a) Uniform speed b) uniform velocity c)uniform acceleration
d) average velocity
3. An ant walk with speed:
a)0.1m/s
b)0.1ms
c)0.01m/s
d) 100m/s
4. The dimension of acceleration is:
[LT-1]
b) [LT-2]
c) [LT]
d) [LT-1]
5. When a velocity of body changes with constant rate then acceleration is:
Zero b) Constant c) negative d) positive
6. Slope of velocity time graph is:
a) Distance
b) power
c) acceleration d)displacement
7. Area under velocity time graph is equal to:
a)Displacement
d) distance
c) acceleration
d) work done
8. When a body moves with constant velocity, then velocity time graph is:
a) Parabola
b) straight line c) curve d) hyperbola
9. The distance covered by the a body with uniform acceleration a in time t starting form rest:
a)
½ at2
b)vt
c) ½ at
d) zero
10. A body falling freely strikes the ground in 5 seconds, distance covered it in 5 seconds is:
a) 122.5m
b)122.5cm
c) 123m
d)25m
11. Laws of motions are not valid in a system which is:
a) At rest
b) moving with uniform velocity
c)non inertial d)inertial
12. Dimension of linear inertia is:
a) [MLT2]
b) [ML0 T2]
c) [ML0 T0] d) [MLT1]
13. The magnitude of the force which is producing the acceleration of 10m/s2 in a body of mas 0.5kg is equal to :
a) 3N
b)4N
c) 5N
d) 6N
14. If mass is doubled then acceleration becomes:
a)one fourth b)half
c)double d)constant
15. If the force acting on body is doubled then the acceleration becomes
a) constant
b) Double
c) Half
d) One forth
16. 10N and 20N are acting on body of mass of 2kg the minimum acceleration will be:
a) 10m/s2
b) 20m/s2
c)5m/s2
d) 60m/s2
nd
17. 2 law :
a) ∆P/t=F
b) F=ma
c) both
d) none
18. A body of mass 5kg is acted upon by a constant force of 10N for 7 sec the total change in momentum is:
a) 70N/S
b)100N/S
c)140NS
d)200NS
19. A force of 15N acts on a body of mass5Kg for 5sec to a distance of 10cm, the rate of change of momentum is:
a)75N
b)45N
c)15N
d)15Nm
20. Rate of change of momentum is called:
a)Force
b) pressure
c) Impulse
d)Tension
21. When speed of body is doubled then its:
a) Kinetic energy is doubled
b)P.E is doubled
c) Acceleration is doubled
d) momentum is doubled
22. If the momentum of body is numerically equal to its kinetic energy, then speed of body is:
a)1m/s
b)2m/s
c)4m/s
d)8m/s
23. SI unit of impulse is:
a) N.s
b) J.s
c) Both
d) None
24. Change in momentum is:
a) Force
b) impulse
c) work
d) none
25. Dimensions of impulse are same as that off:
a) Force
b) angular momentum
c)momentum
d) mass
26. Impulse can be defined as:
Chapter #3
MCQS+S.Q
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a) F×d=I
b)F×d=I
c)F×v=I
d)F×a=I
27. In the absence of external forces change in momentum of system is:
a) constant
b) increases
c) decreases
d)Zero
28. For a rocket the change in momentum per second of the ejecting gases is equal to:
a) acceleration of rocket b) velocity of rocket
c) force acting on rocket d)momentum of rocket
29. Before launching of any rocket, the mass of rocket due to fuel is approximately equal to:
a) 90%
b) 65%
c)80%
d)70%
30. The mass of fuel consumed by typical rocket to overcome earth’s gravity is:
a) 1000kg/s
b) 100kg/s
c)10000kg/s
d)10kg/s
31. A typical rocket consume about 10000kg per sec of the fuel and eject burn gases at speed:
a) 2000m/s
b)3000m/s
c)4000m/s
d)5000m/s
32. During the projectile motion the horizontal component of velocity:
a) changes with time
b) becomes zero c)doesn’t change with time but remain constant d) increases with time
33. Which of the following remain constant during the motion of projectile fired from a planet
a) Kinetic energy
b) momentum
c)vertical component of velocity
d)horizontal component of velocity
34. The path of projectile usually appears as:
a) Parabola
b) Hyperbola
c) Straight line
d)none of these
35. During the projectile motion the vertical component of velocity:
a) changes with time
b) becomes zero c)doesn’t change with time but remain constant d) increases with time
36. Motion of projectile is:
a) One dimension
b) Two dimension
c)Three dimension d)None of these
37. A bomber drops its bomb when it is vertically above the target, it misses the target due to
a) Horizontal component of velocity b) Pull of the earth c) Vertical component of velocity d) Acceleration due to gravity
38. A ball is thrown up at an angle of 60 0 with horizontal, with a speed of 14m/s the velocity of ball at highest point is:
a) 14m/s
b)0m/s
c)7m/s
d)16m/s
39. The velocity of projectile at its maximum height is:
a) visinƟ
b) vicosƟ
c) maximum
d)zero
40. Height of projectile is maximum at an angle of:
a)450
b) 600
c)300
d)900
41. Time of flight for projectile is
a)
2𝑣𝑖 𝑠𝑖𝑛𝜃
(b)
2𝑔
𝑣𝑖2 𝑠𝑖𝑛2 𝜃
c)
2𝑔
𝑣𝑖2 𝑠𝑖𝑛𝜃
2𝑔
d)none of these
42. If the initial velocity if a projectile becomes double. The time of flight will be:
a) Double
b) same
c)three times
d)four times
43. Range of projectile is proportional to
a) sinƟ
b)Sin2Ɵ
c)2sinƟ
d)None of these
44. A projectile will cover same horizontal distance when the initial angle of projection are:
a) 300, 600
b) 200, 500
c) 200, 400
d)200, 800
45. Range of projectile are equal for pair of angles:
a) 450,500
b) 450,600
c) 400,500
d) 450,550
46. Which shows the correct relation between H and T of projectile :
a)𝐻 =
𝑔𝑇 2
8
b)
𝐻=
𝑔𝑇 2
𝑔
c) 𝐻 =
8𝑔
𝑇2
d) 𝐻 =
8
𝑔𝑇 2
47. The angle of projection for which its maximum height is equal to range is:
a)460
b) 760
c) 560
d) 660
48. The ballistic missiles are useful only for:
a) short range
b)Long range
c)Vertical range
d)normal range
49. An unpowered and unguided missile is called:
a) simple missile
b)ballistic missile
c) long range missile
d) remote control missile
Important Short questions from chapter:
1. Define positive and negative acceleration with there direction?
2. How acceleration and distance can be calculated from velocity time graph?
3. Describe Newton First law of motion?
Chapter #3
MCQS+S.Q
4.
5.
6.
7.
8.
9.
Define inertial frame of reference? Is earth an inertial frame of reference?
State Newton’s second law of motion and define S.I unit of force?
State Newton third law of motion and give at least two examples?
A shell is explode in two pieces why they move in opposite direction?
A bullet is fired from a rifle. Derive the relation for velocity of rifle.
Define Ballistic flight and ballistic trajectory?
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