Error Calculation
1.
A physical parameter a can be determined by measuring the parameters b, c, d and e using
the relation a = b  c  / d  e  . If the maximum errors in the measurement of b, c, d and e are
b1 %, c1 %, d 1 % and e1 %, then the maximum error in the value of a determined by the
experiment is
(a) ( b1  c1  d 1  e 1 )%
(b) ( b 1  c 1  d 1  e 1 )%
(c) ( b1  c1  d 1  e 1 )%
(d) ( b1  c1  d 1  e 1 )%
2.
3.
4.
5.
6.
The relative density of material of a body is found by weighing it first in air and then in water. If the
weight in air is (5.00 0.05 ) Newton and weight in water is (4.00  0.05) Newton. Then the relative
density along with the maximum permissible percentage error is
(a) 5.0  11%
(b) 5.0  1%
(c) 5.0  6%
(d) 1.25  5%
The resistance R =
V
where V= 100  5 volts and i = 10  0.2 amperes. What is the total error in R
i
(a) 5%
(b) 7%
(c) 5.2%
(d)
5
%
2
The period of oscillation of a simple pendulum in the experiment is recorded as 2.63 s, 2.56 s, 2.42
s, 2.71 s and 2.80 s respectively. The average absolute error is
(a) 0.1 s
(b) 0.11 s
(c) 0.01 s
(d) 1.0 s
The length of a cylinder is measured with a meter rod having least count 0.1 cm. Its diameter is
measured with vernier calipers having least count 0.01 cm. Given that length is 5.0 cm. and radius
is 2.0 cm. The percentage error in the calculated value of the volume will be
(a) 1%
(b) 2%
(c) 3%
(d) 4%
In an experiment, the following observation's were recorded : L = 2.820 m, M = 3.00 kg, l = 0.087
cm, Diameter D = 0.041 cm Taking g = 9.81 m /s 2 using the formula , Y=
4 MgL
D 2 l
, the maximum permissible
error in Y is
(a) 7.96%
(c) 6.50%
7.
(b) 4.56%
(d) 8.42%
According to Joule's law of heating, heat produced H  I 2 Rt, where I is current, R is resistance and
t is time. If the errors in the measurement of I, R and t are 3%, 4% and 6% respectively then error
in the measurement of H is
(a)  17%
(c)  19%
(b)  16%
(d)  25%
8.
If there is a positive error of 50% in the measurement of velocity of a body, then the error in the
measurement of kinetic energy is
(a) 25%
(c) 100%
(b) 50%
(d) 125%
1
9.
A physical quantity P is given by P=
A3B 2
C
4
3
D2
. The quantity which brings in the maximum percentage
error in P is
(a) A
(c) C
10.
(b) B
(d) D
If the length of rod A is 3.25  0.01 cm and that of B is 4.19  0.01 cm then the rod B is longer than
rod A by
(a) 0.94  0.00 cm
(b) 0.94  0.01 cm
(c) 0.94  0.02 cm
(d) 0.94  0.005 cm
1
a
2
a
3
b
4
b
5
c
6
c
7
b
8
d
9
c
10
c
Significant Figures
1.
The number of significant figures in all the given numbers 25.12, 2009, 4.156 and 1 .217  10 4 is
[Pb. PET 2003]
2.
3.
4.
5.
6
(a) 1
(b) 2
(c) 3
(d) 4
The decimal equivalent of 1/20 upto three significant figures is
(a) 0.0500
(b) 0.05000
(c) 0.0050
(d) 5.0 × 10-2
What is the number of significant figures in 0.310×103
(a) 2
(b) 3
(c) 4
(d) 6
If L  2 .331 cm, B  2.1 cm , then L  B 
[DCE 2003]
(a) 4.431 cm
(b) 4.43 cm
(c) 4.4 cm
(d) 4 cm
If 97.52 is divided by 2.54, the correct result in terms of significant figures is
(a) 38.4
(b) 38.3937
(c) 38.394
(d) 38.39
The number of significant figures in (i) 0.03800 and (ii) 90.00 is (A) (i) 4 (ii) 4
(B) (i) 2 (ii) 1
(C) (i) 3 (ii) 3
7
8
9

(D) (i) 2 (ii) 4
The number of significant figures in 3.04 × 1023 is (A) 2
(B) 3
(C) 23
(D) 25
The number of significant figures in 0.0060 × 10–18 m is (A) 1
(B) 2
(C) 4
(D) 5
The number of significant figures in (i) 10.85 meter (ii) 0.0001234 kg is 
(A) (i) 4 (ii) 4
(B) (i) 3 (ii) 7
(C) (i) 4 (ii) 7
(D) (i) 2 (ii) 7

10 Which of the following measurements is most accurate ?
(A) 9 × 10–2m
(B) 90 × 10–3m
(C) 900 × 10–4m
(D) 0.090m
1
d
2
a
3
b
4
c
5
a
6
a
7
b
8
b
9
a
10
c
1
2
3
4
5
6
7
8
9
10
Vernier calliper and rounding off
Formulas (H,R,T)
1.
2.
3.
A projectile fired with initial velocity u at some angle  has a range R . If the initial velocity be
doubled at the same angle of projection, then the range will be
(a) 2 R
(b) R / 2
(c) R
(d) 4 R
If the initial velocity of a projectile be doubled, keeping the angle of projection same, the
maximum height reached by it will
(a) Remain the same
(b) Be doubled
(c) Be quadrupled
(d) Be halved
In the motion of a projectile freely under gravity, its
(a) Total energy is conserved
(b) Momentum is conserved
(c) Energy and momentum both are conserved
(d) None is conserved
4.
The range of a projectile for a given initial velocity is maximum when the angle of projection is
. The range will be minimum, if the angle of projection is
(a)
(b)
90 o
(c) 60 o
5.
45 o
180 o
(d) 75 o
The angle of projection at which the horizontal range and maximum height of projectile are equal
is
[Kurukshetra CEE 1996; BCECE 2003; Pb. PET 2001]
(a)
45
(c)   tan 1 4 or (
6.
(b)   tan (0 . 25 )
1
o
 76 )
(d)
60 o
A ball is thrown upwards and it returns to ground describing a parabolic path. Which of the
following remains constant
[BHU 1999; DPMT 2001; AMU (Engg.) 2000]
(a) Kinetic energy of the ball
(b) Speed of the ball
(c) Horizontal component of velocity
(d) Vertical component of velocity
7.
At the top of the trajectory of a projectile, the directions of its velocity and acceleration are
(a) Perpendicular to each other
(b) Parallel to each other
(c) Inclined to each other at an angle of
45 o
(d) Antiparallel to each other
8.
An object is thrown along a direction inclined at an angle of
horizontal range of the particle is equal to
(a) Vertical height
(b) Twice the vertical height
45 o
with the horizontal direction. The
[MP PMT 1985]
(c) Thrice the vertical height
(d) Four times the vertical height
9.
The horizontal range is four times the maximum height attained by a projectile. The angle of
projection is
[MP PET 1994; CBSE PMT 2000; RPET 2001]
(a)
10.
90
o
(b)
(c) 45
o
(d) 30 o
60
o
A ball is projected with kinetic energy E at an angle of
during its flight, its kinetic energy will be
45 o
to the horizontal. At the highest point
[MP PMT 1994; CBSE PMT 1997, 2001; AIEEE 2002; Pb. PMT 2004; Orissa PMT 2004]
(a) Zero
(c)
(b)
E
E
2
(d) E
2
1
d
2
c
3
a
4
a
5
c
6
c
7
a
8
d
9
c
10
b
Avg. & Insta. Velocity
1.
A person travels along a straight road for half the distance with velocity v1 and the remaining half
distance with velocity v 2 The average velocity is given by
(a) v1v 2
(c)
2.
v1  v 2
2
v 22
v12
(d)
2v1v 2
v1  v 2
The displacement-time graph for two particles A and B are straight lines inclined at angles of
and 60 o with the time axis. The ratio of velocities of V A : VB is
(a) 1 : 2
3.
(b)
30 o
(b) 1 : 3
(c) 3 : 1
(d) 1 : 3
A car travels from A to B at a speed of 20 km / hr and returns at a speed of 30 km / hr . The average
speed of the car for the whole journey is
(a) 25 km / hr
(b) 24 km / hr
(c) 50 km / hr
(d) 5 km / hr
4.
5.
1.
2.
3.
A boy walks to his school at a distance of 6 km with constant speed of 2.5 km/hour and walks back
with a constant speed of 4 km/hr. His average speed for round trip expressed in km/hour, is
(a) 24/13
(b) 40/13
(c) 3
(d) ½
A car travels the first half of a distance between two places at a speed of 30 km/hr and the second
half of the distance at 50 km/hr. The average speed of the car for the whole journey is
(a) 42.5 km/hr
(b) 40.0 km/hr
(c) 37.5 km/hr
(d) 35.0 km/hr
The motion of a particle is described by the equation x  a  bt 2 where a  15 cm and b  3 cm/s2.
Its instantaneous velocity at time 3 sec will be
(a) 36 cm/sec
(b) 18 cm/sec
(c) 16 cm/sec
(d) 32 cm/sec
A body moves from rest with a constant acceleration of 5 m / s 2 . Its instantaneous speed (in m / s)
at the end of 10 sec is
(a) 50
(b) 5
(c) 2
(d) 0.5
The acceleration ' a' in m / s 2 of a particle is given by a  3 t 2  2 t  2 where t is the time. If the
particle starts out with a velocity u  2 m / s at t  0 , then the velocity at the end of 2 second is
(a) 12 m/s
(c) 27 m/s
(b) 18 m/s
(d) 36 m/s
4.
The displacement of a particle, moving in a straight line, is given by
metres and t in seconds. The acceleration of the particle is
(a) 2 m/s2
(b) 4 m/s2
(c) 6 m/s2
(d) 8 m/s2
5.
The instantaneous velocity of a body can be measured
(a) Graphically
(b) Vectorially
(c) By speedometer
(d) None of these
s  2t 2  2t  4
where s is in
1
d
2
d
3
b
4
b
5
c
6
b
7
a
8
b
9
b
10
ac
Crossing the river
1.
A boat is moving with velocity of 3ˆi  4 ˆj in river and water is moving with a velocity of
with respect to ground. Relative velocity of boat with respect to water is :
(a)  6ˆi  8 ˆj
2.
3.
4.
 3ˆi  4 ˆj
(b) 6ˆi  8 ˆj
(c) 8 î
(d) 6 î
A boat is sent across a river with a velocity of 8 km/hr. If the resultant velocity of boat is 10 km/hr,
then velocity of the river is :
(a) 10 km/hr
(b) 8 km/hr
(c) 6 km/hr
(d) 4 km/hr
A boat moves with a speed of 5 km/h relative to water in a river flowing with a speed of 3 km/h
and having a width of 1 km. The minimum time taken around a round trip is
(a) 5 min
(b) 60 min
(c) 20 min
(d) 30 min
A river is flowing from W to E with a speed of 5 m/min. A man can swim in still water with a
velocity 10 m/min. In which direction should the man swim so as to take the shortest possible path
to go to the south.
[BHU 2005]
(a) 30° with downstream (b) 60° with downstream
5
(c)120° with downstream
(d) 90° with downstream
A boat moves relative to water with a velocity which is 1/n times the river flow velocity. At what
angle to the stream direction must be boat move to minimize drifting ?
(B) sin–1 (1/n)
(A) /2
(C)
6

+ sin–1(1/n)
2
(D)

– sin–1(1/n)
2
A boat which has a speed of 5 km/hr in still water crosses a river of width 1 km along the
shortest possible path in 15 minutes. The velocity of the river water in km/hr is :
7.
8
(A) 1
(B) 3
(C) 4
(D)
41
A river is flowing from west to east with a speed of 5 m/min. A man can swim in still water with
a velocity 10 m/min. In which direction should the man swim, so as to take the shortest possible
path to go to the south?
(a) 30° with downstream
(b) 60° with downstream
(c) 120° with downstream
(d) towards south
A man can row a boat with speed 4 km/hr in still water. If the velocity of water in river is
3 km/hr. The time taken to reach just opposite end is (river width = 500 m)
(a)
500
7
hr
(b)
1
2 7
hr
(c) 100 hr
(d) none
9.
A boat which has a speed of 5 m/s in still water crosses the river of width 25 m in 10
seconds. The boat is heading at an angle of  with downstream, where  is equal to
(a) 150°
(b) 120°
(c) 90°
(d) 60°
10.
A swimmer wishes to cross a 800 m wide river flowing at 6 km/hr. His speed with respect to
water is 4 km/hr. He crosses the river in shortest possible time. He is drifted downstream on
reaching the other bank by a distance of
(a) 800 m
(b) 1200 m
(c) 400
13 m
(d) 2000 m
1
b
2
c
3
d
4
c
5
c
6
b
7
c
8
b
9
a
10
b
Connected Mass System
1.
2.
A 2 kg block is lying on a smooth table which is connected by a body of mass 1 kg by a string which passes through a
pulley. The 1 kg mass is hanging vertically. The acceleration of block and tension in the string will be
(a)
3 . 27 m / s 2 , 6 . 54 N
(b)
4 . 38 m / s 2 , 6 . 54 N
(c)
3 . 27 m / s 2 , 9 . 86 N
(d)
4 . 38 m / s 2 , 9 . 86 N
A light string passes over a frictionless pulley. To one of its ends a mass of 6 kg is attached. To its other end a mass of 10
kg is attached. The tension in the thread will be
(a) 24.5 N
(b) 2.45 N
(c) 79 N
(d) 73.5 N
3.
4.
6 kg
10 kg
USS 150) Two masses of 5kg and 10kg are connected to a pulley as shown. What will be the acceleration of the system
(g  acceleration due to gravity)
(a)
g
(b)
g
2
(c)
g
3
(d)
g
4
5 kg
10 kg
A block A of mass 7 kg is placed on a frictionless table. A thread tied to it passes over a frictionless pulley and carries a
body B of mass 3 kg at the other end. The acceleration of the system is (given g = 10 ms 2 )
(a) 100 ms 2
A
(b) 3 ms 2
(c)
10 ms 2
B
(d) 30 ms 2
5.
Three blocks of masses 2 kg, 3 kg and 5 kg are connected to each other with light string and are then placed on a frictionless
surface as shown in the figure. The system is pulled by a force F  10 N , then tension T1 
(a) 1N
(b) 5 N
(c) 8 N
10N
2kg
T1
3kg
T2
5kg
(d) 10 N
6.
Two masses m 1 and m 2 are attached to a string which passes over a frictionless smooth pulley. When m 1  10 kg ,
m 2  6 kg, the acceleration of masses is
(a) 20 m / s 2
(b) 5 m / s 2
(c) 2.5 m / s 2
m1
m2
(d) 10 m / s 2
7.
A body of weight 2kg is suspended as shown in the figure. The tension T1 in the horizontal string (in kg wt) is
30°
8.
(a)
2/ 3
(b)
3 /2
(c)
2 3
(d)
2
T1
2 kg-wt
One end of a massless rope, which passes over a massless and frictionless pulley P is tied to a hook C while the other end
is free. Maximum tension that the rope can bear is 360 N. with what value of minimum safe acceleration (in ms 2 ) can a
monkey of 60 kg move down on the rope
P
(a) 16
(b) 6
(c) 4
C
(d) 8
9.
A light string passing over a smooth light pulley connects two blocks of masses m 1 and m 2 (vertically). If the acceleration
of the system is g/8 then the ratio of the masses is
10.
(a) 8 : 1
(b) 9 : 7
(c) 4 : 3
(d) 5 : 3
Two masses m 1  5 kg and m 2  4 . 8 kg tied to a string are hanging over a light frictionless pulley. What is the
acceleration of the masses when they are free to move (g  9 .8 m / s 2 )
0 .2 m / s 2
(a)
(b) 9 . 8 m / s 2
5 m / s2
(c)
(d) 4 . 8 m / s 2
m1
1
6
m2
a
2
d
3
c
4
b
5
c
c
7
c
8
c
9
b
10
a
Static Friction
1.
To avoid slipping while walking on ice, one should take smaller steps because of the
(a) Friction of ice is large
(b) Larger normal reaction
(c)
Friction of ice is small
(d) Smaller normal reaction
2.
3.
A box is lying on an inclined plane what is the coefficient of static friction if the box starts sliding
when an angle of inclination is 60o
(a) 1.173
(b) 1.732
(c) 2.732
(d) 1.677
A block of mass 2 kg is kept on the floor. The coefficient of static friction is 0.4. If a force F of 2.5
Newtons is applied on the block as shown in the figure, the frictional force between the block and
the floor will be
(a) 2.5 N
(b) 5 N
F
(c) 7.84 N
(d) 10 N
4.
Which one of the following is not used to reduce friction
(a) Oil
(c)
5.
7.
(d) Graphite
If a ladder weighing 250N is placed against a smooth vertical wall having coefficient of friction
between it and floor is 0.3, then what is the maximum force of friction available at the point of
contact between the ladder and the floor
75 N
(b) 50 N
(c) 35 N
(d) 25 N
(a)
6.
Sand
(b) Ball bearings
A body of mass 2 kg is kept by pressing to a vertical wall by a force of 100 N. The coefficient of
friction between wall and body is 0.3. Then the frictional force is equal to
(a) 6 N
(b)
20 N
(c) 600 N
(d) 700 N
A horizontal force of 10 N is necessary to just hold a block stationary against a wall. The coefficient
of friction between the block and the wall is 0.2. the weight of the block is
(a)
2N
(b) 20 N
(c) 50 N
(d) 100 N
10 N
8.
The coefficient of static friction,  s , between block A of mass 2 kg and the table as shown in the
figure is 0.2. What would be the maximum mass value of block B so that the two blocks do not
move? The string and the pulley are assumed to be smooth and massless. (g  10 m / s 2 )
2 kg
A
(a) 2.0 kg
(b) 4.0 kg
B
(c) 0.2 kg
(d) 0.4 kg
9.
If mass of A  10 kg , coefficient of static friction
= 0.2, coefficient of kinetic friction = 0.2. Then
mass of B to start motion is
10 kg
(a) 2 kg
A
(b) 2.2 kg
(c) 4.8 kg
B
(d) 200 gm
10.
A uniform metal chain is placed on a rough table such that one end of chain hangs down over the
edge of the table. When one-third of its length hangs over the edge, the chain starts sliding. Then,
the coefficient of static friction is
(a)
3
4
(b)
1
4
(c)
2
3
(d)
1
2
1
c
2
b
3
a
4
c
5
a
6
b
7
a
8
d
9
a
10
d
Acceleration in Circular Motion
1.
The acceleration of a train travelling with speed of 400 m/s as it goes round a curve of radius 160
m, is
[Pb. PET 2003]
(a) 1 km / s
2
(c) 10 m / s 2
2.
(d) 1 m / s 2
A particle moves with constant speed v along a circular path of radius r and completes the circle in
time T. The acceleration of the particle is
[Orissa JEE 2002]
(a) 2  v / T
(b) 2  r / T
(c) 2  r 2 / T
3.
(b) 100 m / s
2
(d) 2  v 2 / T
A stone ties to the end of a string 1m long is whirled in a horizontal circle with a constant speed. If
the stone makes 22 revolution in 44 seconds, what is the magnitude and direction of acceleration
of the stone
[CBSE PMT 2005]
(a)
2
4
ms  2 and direction along the radius towards the centre
(b)  2 ms 2 and direction along the radius away from the centre
(c)  2 ms 2 and direction along the radius towards the centre
(d)  2 ms 2 and direction along the tangent to the circle
4.
A car is moving with speed 30 m / sec on a circular path of radius 500 m. Its speed is increasing at
the rate of 2m / sec 2 , What is the acceleration of the car
[MP PMT 2003; Roorkee 1982; RPET 1996; MH CET 2002]
5.
6.
7.
8.
(a) 2m / sec 2
(b) 2 . 7 m / sec 2
(c) 1 . 8 m / sec 2
(d) 9 .8 m / sec 2
A stone is tied to one end of a string 50 cm long is whirled in a horizontal circle with a constant
speed. If the stone makes 10 revolutions in 20 s, what is the magnitude of acceleration of the
stone
[Pb. PMT 2000]
2
2
(a) 493 cm/s
(b) 720 cm/s
(c) 860 cm/s2
(d) 990 cm/s2
If a cycle wheel of radius 4 m completes one revolution in two seconds. Then acceleration of a
point on the cycle wheel will be
[Pb. PMT 2001]
2
2
2
2
(a)  m / s
(b) 2 m / s
2
2
(c) 4 m / s
(d) 8 m /s 2
A cycle wheel of radius 0.4 m completes one revolution in one second then the acceleration of a
point on the cycle wheel will be
[MH CET (Med.) 1999]
(a) 0.8 m/s2
(b) 0.4 m/s2
(c) 1 . 6  2 m / s 2
(d) 0 .4  2 m / s 2
Certain neutron stars are believed to be rotating at about 1 rev / sec . If such a star has a radius of 20
km, the acceleration of an object on the equator of the star will be
[NCERT 1982]
(a) 20  10 8 m / sec 2
9.
(b) 8  10 5 m / sec 2
(c) 120  10 5 m / sec 2
(d) 4  10 8 m / sec 2
An electric fan has blades of length 30 cm as measured from the axis of rotation. If the fan is
rotating at 1200 r.p.m. The acceleration of a point on the tip of the blade is about
[CBSE PMT 1990]
(a) 1600 m / sec
2
(b) 4740 m / sec
(c) 2370 m / sec
2
(d) 5055 m / sec 2
2
1
a
2
a
3
c
4
b
6
a
7
c
8
c
9
b
5
a
Vertical Circular Motion
1.
In a circus stuntman rides a motorbike in a circular track of radius R in the vertical plane. The
minimum speed at highest point of track will be
[CPMT 1979; JIPMER 1997; RPET 1999]
2.
3.
(a)
2 gR
(b) 2 gR
(c)
3 gR
(d)
gR
A block of mass m at the end of a string is whirled round in a vertical circle of radius R . The critical
speed of the block at the top of its swing below which the string would slacken before the block
reaches the top is
[DCE 1999, 2001]
(a) Rg
(b) (Rg )2
(c) R / g
(d)
Rg
A sphere is suspended by a thread of length l . What minimum horizontal velocity has to be
imparted the ball for it to reach the height of the suspension
[ISM Dhanbad 1994]
4.
(a) gl
(b) 2 gl
(c)
(d)
gl
2 gl
A bottle of sodawater is grasped by the neck and swing briskly in a vertical circle. Near which
portion of the bottle do the bubbles collect
(a) Near the bottom
(b) In the middle of the bottle
(c) Near the neck
(d) Uniformly distributed in the bottle
5.
6.
A bucket tied at the end of a 1.6 m long string is whirled in a vertical circle with constant speed.
What should be the minimum speed so that the water from the bucket does not spill, when the
bucket is at the highest position (Take g  10m / sec 2 )
[AIIMS 1987]
(a) 4 m/sec
(b) 6.25 m/sec
(c) 16 m/sec
(d) None of the above
A wheel is subjected to uniform angular acceleration about its axis. Initially its angular velocity is
zero. In the first 2 sec, it rotates through an angle 1 . In the next 2 sec, it rotates through an
additional angle  2 . The ratio of  2 / 1 is
[AIIMS 1985]
7.
(a) 1
(b) 2
(c) 3
(d) 5
A 1 kg stone at the end of 1 m long string is whirled in a vertical circle at constant speed of 4
m/sec. The tension in the string is 6 N, when the stone is at (g = 10 m/sec2)
[AIIMS 1982]
(a) Top of the circle
(b) Bottom of the circle
(c) Half way down
(d) None of the above
8.
A cane filled with water is revolved in a vertical circle of radius 4 meter and the water just does not
fall down. The time period of revolution will be
[CPMT 1985;
RPET 1995; UPSEAT 2002; MH CET 2002]
9.
(a) 1 sec
(b) 10 sec
(c) 8 sec
(d) 4 sec
A 2 kg stone at the end of a string 1 m long is whirled in a vertical circle at a constant speed. The
speed of the stone is 4 m/sec. The tension in the string will be 52 N, when the stone is
[AIIMS 1982]
(a) At the top of the circle
(b) At the bottom of the circle
(c) Halfway down
(d) None of the above
10.
A body slides down a frictionless track which ends in a circular loop of diameter D , then the
minimum height h of the body in term of D so that it may just complete the loop, is
(a) h 
5D
2
(b) h 
5D
4
(c) h 
3D
4
(d) h 
D
4
1
d
2
d
3
d
4
c
5
a
6
c
7
a
8
d
9
b
10
b
Work Done by Force
1.
2.
A force of (3 ˆi  4 ˆj) Newton acts on a body and displaces it by (3 ˆi  4ˆj)m . The work done by the
force is
[AIIMS 2001]
(a) 10 J
(b) 12 J
(c) 16 J
(d) 25 J
A 50kg man with 20kg load on his head climbs up 20 steps of 0.25m height each. The work done in
climbing is
[JIPMER 2002]
(a) 5 J
(c) 100 J
3.
(b) 350 J
(d) 3430 J
A force F  6ˆi  2ˆj  3kˆ acts on a particle and produces a displacement of s  2ˆi  3 ˆj  x kˆ . If the
work done is zero, the value of x is
(a) – 2
(b) 1/2
(c) 6
(d) 2
4.
[Kerala PMT 2002]


A particle moves from position r1  3ˆi  2ˆj  6 kˆ to position r2  14 ˆi  13 ˆj  9 kˆ under the action of
force 4ˆi  ˆj  3kˆ N . The work done will be
(a) 100 J
(c) 200 J
5.

(b) 50 J
(d) 75 J

A force (F)  3ˆi  cˆj  2kˆ acting on a particle causes a displacement: (s )  4ˆi  2ˆj  3kˆ in its own
direction. If the work done is 6 J , then the value of 'c' is
(a) 0
(c) 6
6.
7.
[Pb. PMT 2002,03]
[CBSE PMT 2002]
(b) 1
(d) 12
A force of 5 N acts on a 15 kg body initially at rest. The work done by the force during the first second
of motion of the body is
[JIPMER 1999]
5
J
6
(a) 5 J
(b)
(c) 6 J
(d) 75 J
A force of 5 N, making an angle  with the horizontal, acting on an object displaces it by 0 .4 m
along the horizontal direction. If the object gains kinetic energy of 1J, the horizontal component of
the force is
[EAMCET (Engg.) 2000]
1.
(a) 1.5 N
(b) 2.5 N
(c) 3.5 N
(d) 4.5 N
A position dependent force F  7  2 x  3 x 2 newton acts on a small body of mass 2 kg and displaces
it from x  0 to x  5 m . The work done in joules is[CBSE PMT 1994]
(a) 70
(c) 35
(b) 270
(d) 135
2.
A body of mass 3 kg is under a force, which causes a displacement in it is given by S 
t3
3
(in m).
Find the work done by the force in first 2 seconds[BHU 1998]
3.
(a) 2 J
(b) 3.8 J
(c) 5.2 J
(d) 24 J
The force constant of a wire is k and that of another wire is 2k . When both the wires are stretched
through same distance, then the work done
[MH CET 2000]
(a) W2  2W12
(b) W2  2W1
(c) W2  W1
(d) W2  0 .5W1
1
d
2
d
3
d
4
a
5
c
6
b
7
b
8
d
9
d
10
b
Relation between Force & potential Energy
1.
A spring of force constant 800 N/m has an extension of 5cm. The work done in extending it from
5cm to 15 cm is
[AIEEE 2002]
2.
3.
4.
(a) 16 J
(b) 8 J
(c) 32 J
(d) 24 J
When a spring is stretched by 2 cm, it stores 100 J of energy. If it is stretched further by 2 cm, the
stored energy will be increased by
[Orissa JEE 2002]
(a) 100 J
(b) 200 J
(c) 300 J
(d) 400 J
A spring when stretched by 2 mm its potential energy becomes 4 J. If it is stretched by 10 mm, its
potential energy is equal to
[BCECE 2003]
(a) 4 J
(b) 54 J
(c) 415 J
(d) None
A spring of spring constant 5  103 N/m is stretched initially by 5cm from the unstretched position.
Then the work required to stretch it further by another 5 cm is
[AIEEE 2003]
(a) 6.25 N-m
(b) 12.50 N-m
(c) 18.75 N-m
5.
6.
(d) 25.00 N-m
A mass of 0.5kg moving with a speed of 1.5 m/s on a horizontal smooth surface, collides with a
nearly weightless spring of force constant k  50 N / m . The maximum compression of the spring
would be
[CBSE PMT 2004]
(a) 0.15 m
(b) 0.12 m
(c) 1.5 m
(d) 0.5 m
A particle moves in a straight line with retardation proportional to its displacement. Its loss of
kinetic energy for any displacement x is proportional to [AIEEE 2004]
(a) x 2
(c) x
7.
8.
(b) e x
(d) log e x
A spring with spring constant k when stretched through 1 cm, the potential energy is U. If it is
stretched by 4 cm. The potential energy will be
[Orissa PMT 2004]
(a) 4U
(b) 8U
(c) 16 U
(d) 2U
A spring with spring constant k is extended from x  0 to x  x 1 . The work done will be
[Orissa
PMT 2004]
9.
1 2
kx 1
2
(a) kx 12
(b)
(c) 2kx 12
(d) 2kx 1
If a long spring is stretched by 0.02 m, its potential energy is U. If the spring is stretched by 0.1 m,
then its potential energy will be
[MP PMT 2002; CBSE PMT 2003; UPSEAT 2004]
(a)
10.
U
5
(b) U
(c) 5U
(d) 25U
Natural length of a spring is 60 cm, and its spring constant is 4000 N/m. A mass of 20 kg is hung
from it. The extension produced in the spring is, (Take g  9 .8 m / s 2 )
[DCE 2004]
(a) 4.9 cm
(c) 9.4 cm
(b) 0.49 cm
(d) 0.94 cm
1
b
2
c
3
d
4
c
5
a
6
a
7
c
8
b
9
d
10
a
Centre of mass of Different Figures
1
4
2
4
3
2
4
2
5
4
6
3
7
4
8
3
9
4
10
3
Recoil of Gun & COM of Two Particle System
1.
The law of conservation of momentum for a system is based on Newton's :(1) First law of motion
(2) Second law of motion
(3) Third law of motion
(4) Law of gravitation
2.
A person of mass m is standing on one end of a plank of mass M and length L and floating in
water. The person moves from one end to another and stops. The displacement of the plank is(1)
Lm
(m  M)
(2) Lm (M + m) (3)
(M  m)
Lm
(4)
LM
(m  M)
3.
Bullets of mass 40 g each are fired from a machine gun with a velocity of 103 m/s. If the person
firing the bullets experience an average force of 200 N, then the number of bullets fired per minute will
be(1) 300
4.
(2) 600
(3) 150
(4) 75
If the system is released, then the acceleration of the centre of mass of the system:
(1)
g
4
(2)
(3) g
g
2
(4) 2g
5.
A bomb of 50 Kg is fired from a cannon with a velocity 600 m/s. If the mass of the cannon is 103
kg, then its velocity will be (1) 30 m/s
(2) –30 m/s
(3) 0·30 m/s
(4) –0.30 m/s
Answer
1.
(3)
2.
(1)
3.
(1)
4.
(1)
5.
(2)
Moment of Inertia
1
Two rings of same radius (r) and mass (m) are placed such that their centres are at a common
point and their planes are perpendicular to each other. The moment of inertia of the system
about an axis passing through the centre and perpendicular to plane of one of the ring is -
2
3
4
(A)
1
mr2
2
(B) mr2
(C)
3
mr2
2
(D) 2mr2
A stone of mass 4 kg is whirled in a horizontal circle of radius 1m and makes 2 rev/sec. The
moment of inertia of the stone about the axis of rotation is(A) 64 kg × m2
(B) 4 kg × m2
(C) 16 kg × m2
(D) 1 kg × m2
In an arrangement four particles, each of mass 2 gram are situated at the coordinate points
(3, 2, 0), (1, –1, 0), (0, 0, 0) and (–1, 1, 0). The moment of inertia of this arrangement about the
Z-axis will be(A) 8 units
(B) 16 units
(C) 43 units
(D) 34 units
Two discs have same mass and thickness. Their materials are of densities 1 and 2. The ratio of
their moment of inertia about central axis will be -
5
(A) 1 : 2
(B) 12 : 1
(C) 1 : 12
(D) 2 : 1
Three rings, each of mass P and radius Q are arranged as shown in the figure. The moment of
inertia of the arrangement about YY' axis will be1
Y 2
Q
Q
P
P
Q
P
3
Y'
(A)
7
PQ2
2
(B)
2
PQ2
7
(C)
2
PQ2
5
(D)
5
PQ2
2
6
The moment of inertia depends upon(A) angular velocity of the body
(B) angular acceleration of the body
(C) only mass of the body
(D) distribution of mass and the axis of rotation of the body
7
Three thin uniform rods each of mass M and length L and placed along the three axis of a
Cartesian coordinate system with one end of each rod at the origin. The M.I. of the system
about z-axis is(A)
8
ML2
3
(B)
2ML2
3
(C)
ML2
(D) ML2
6
A circular disc A of radius r is made from an iron plate of thickness t and another circular disc B
of radius 4r is made from an iron plate of thickness t/4. The relation between the moments of
inertia IA and IB is(A) A > B
(B) A = B
(C) A < B
(D) depends on the actual values of t and r.
9
One quarter sector is cut from a uniform disc of radius R. This sector has mass M. It is made to
rotate about a line perpendicular to its plane and passing through the center of the original disc.
Its moment of inertia about the axis of rotation is –
(A)
1
MR2
2
(B)
(C)
1
MR2
8
(D)
1
MR2
4
2 MR2
10
Two spheres of same mass and radius are in contact with each other. If the moment of inertia of
a sphere about its diameter is I, then the moment of inertia of both the spheres about the
tangent at their common point would be (A) 3I
(B) 7I
(C) 4I
(D) 5I
1
c
2
b
3
d
4
d
5
a
6
d
7
b
8
c
9
a
10
b
1
2
3
4
5
6
7
8
9
10
Angular Momentum Conservation
1
A uniform heavy disc is rotating at constant angular velocity () about a vertical axis through its
centre O. Some wax W is dropped gently on the disc. The angular velocity of the disc(A) does not change
(C) decreases
(B) increases
(D) becomes zero
[C]
2
A girl sits near the edge of a rotating circular platform. If the girl moves from circumference
toward the centre of the platform then the angular velocity of the platform will(A) decrease
(B) increase
(C) remain same
(D) becomes zero
[B]
3
A smooth uniform rod of length L and mass M has identical beads of negligible size, each of
mass m , which can slide freely along the rod. Initially the two beads are at the centre of the rod
and the system is rotating with angular velocity 0 about an axis perpendicular to the rod and
passing through the mid point of the rod., There are no external forces. When the beads reach
the ends of the rod, the angular velocity of the rod would be -
4
(A)
M0
M  2m
(B)
M0
M  4m
(C)
M0
M  6m
(D)
M 0
M  8m
[C]
The rate of change of angular momentum is called(A) angular velocity
(B) angular acceleration
(C) force
(D) torque
5
[D]
A man sitting on a rotating stool with his arms stretched out, suddenly lowers his hands(A) his angular velocity decreases
(B) his moment of inertia decreases.
(C) his angular velocity remains constant
(D) his angular momentum increases.
6
7
8
[B]
The rotational kinetic energy of a rigid body of moment of inertia 5 kg-m2 is 10 joules. The
angular momentum about the axis of rotation would be (A) 100 joule-sec
(B) 50 joule-sec
(C) 10 joule-sec
(D) 2 joule –sec [C]
A circular ring of mass 1kg and radius 0.2m executes 10 revolutions per sec. Its angular
momentum would be - (kg-m2/sec)
(A) 0.025
(B) 0.25
(C) 2.5
(D) 25
[C]
A particle is confined to rotate in a circular path decreasing linear speed, then which of the
following is correct ?

(A) L (angular momentum) is conserved about the centre

(B) only direction of angular momentum L is conserved
(C) it spirals towards the centre
(D) its acceleration is towards the centre
[B]
Formula For Rolling
1
A disc is performing pure rolling on a smooth stationary surface with constant angular velocity
as shown in figure. At any instant, for the lower most point of the disc.
V/R
R
V
(A) Velocity is v, acceleration is zero
(B) Velocity is zero, acceleration is zero
(C) Velocty is v, acceleration is
v2
R
(D) Velocity is zero, acceleration is nonzero
2
Figure shows a smooth inclined plane of inclination  fixed in a car. A sphere is set in pure rolling
on the incline. For what value of 'a' (the acceleration of car in horizontal direction) the sphere
will continue pure rolling ?
a

3
(A) g cos 
(B) g sin 
(C) g cot 

(D) g tan  
A sphere of radius 'R' is rolling over a horizontal surface. All measurement are made with respect
to surface over which sphere is rolling. Which of the following strictly confirms pure rolling
motion of sphere over horizontal surface ?
(A) xcm = R : xcm & R in meter & '' is in radian
(B) vcm = R : R in meter, vcm in m/s, '' in rad/sec
(C) acm = R : acm in cm/s2, R in cm,  in rad/s2
(D) All of the above
4.
A ring is rolling without slipping. Its energy of translation is E. Its total kinetic energy will be :(1) E
(2) 2E
(3) 3E
(4) 4E
5.
A thin hollow cylinder open at both ends slides without rotating and then rolls without slipping
with the same speed. The ratio of the kinetic energies in the two cases is
(1) 1 : 1
(2) 1 : 2
(3) 2 : 1
(4) 1 : 4
6.
A solid sphere of mass M and radius R rolls on a horizontal surface without slipping. The ratio of
rotational K.E. to total K.E. is :(1)
1
2
(2)
3
7
(3)
2
7
(4)
2
10
7.
A disc is rolling on an inclined plane without slipping then what fraction of its total energy will be
in form of rotational kinetic energy :(1) 1 : 3
(2) 1 : 2
(3) 2 : 7
(4) 2 : 5
8.
A wheel is rolling along the ground with a speed of 2 m/s. The magnitude of the linear velocity
of the points at the extremities of the, horizontal diameter of the wheel is equal to
(1) 2 10 m/s
(3) 2 2 m/s
(2) 2 3 m/s
(4) 2 m/s
Answer
1.
(d)
2.
(d)
7.
(1)
8.
(3)
3.
(d)
4.
(2)
5.
(2)
6.
(3)
Torque Balance
1.
A particle of mass m and radius of gyration K is rotating with an angular acceleration . The
torque acting on the particle is
(1)
1
mK2
2
(2) mK2
(3) mK2/
(4)
1 2
mK 
4
2.
The grinding stone of a flour mill is rotating at 600 rad/sec. for this power of 1.2 k watt is used
the effective torque on stone in N-m will be
(1) 1
3
(2) 2
(3) 3
(4) 4
A rigid body is rotating about an axis. To stop the rotation, we have to apply :(1) pressure
(2) force
(3) momentum (4) torque
4.
A wheel has moment of inertia 5 × 10–3 kg m2 and is making 20 rev/sec. The torque needed to
stop it in 10 sec is . . . . . . . . . . . . . × 10–2 N-m :(1) 2
(2) 2.5
(3) 4 

(4) 4.5
5.
A wheel having moment of inertia 2 kg-m2 about its vertical axis, rotates at the rate of 60 rpm
about the axis. The torque which can stop the wheel's rotation in one minute would be :(1)

N-m
12
(2)

N-m
15
(3)

N-m
18
(4)
2
N-m
15
6
A constant torque acting on a uniform circular wheel changes its angular momentum from A0 to
4 A0 in 4 seconds. The magnitude of this torque is :(1)
7
3A0
4
(2) A0

(3) 4 A0
(4) 12 A0

The torque of force F  2iˆ  3jˆ  4kˆ newton acting at a point r  3iˆ  2ˆj  3kˆ meter about origin
is:
(1) 6iˆ  6ˆj  12kˆ N  m
(2) 6iˆ  6ˆj  12kˆ N  m
(3) 17iˆ  6ˆj  13kˆ N  m
(4) 17iˆ  6ˆj  13kˆ N  m
8.
When constant torque is acting on a body then :(1) body maintain its state or moves in straight line with same velocity
(2) acquire linear acceleration
(3) acquire angular acceleration
(4) rotates with a constant angular velocity
9
If torque on a body is zero, then which is conserved:
(1) force
(2) linear momentum
(3) angular momentum
(4) angular impulse
10.
If I = 50 kg-m2, then how much torque will be applied to stop it in 10 sec. Its initial angular speed
is 20 rad/sec. :(1) 100 N-m
(2) 150 N-m
(3) 200 N-m
(4) 250 N-m
Answer
1.
(2)
2.
(2)
3.
(4)
4.
(1)
7.
(3)
8.
(3)
9.
(3)
10.
(1)
5.
(2)
6.
(1)
bubble
Surface tension,, capillary, Water drop and soap bubbl
1.
Spiders and insects move and run about on the surface of water w
without
ithout sinking because :
(1) Elastic membrane is formed on water due to property of surface tension
(2) Spiders and insects are ligther
(3) Spiders and insects swim on water
(4) Spiders and insects experience rip-thrust
rip
2.
shaped wire and a light slider supports a weight of
A thin liquid f.ilm formed between a U-shaped
–2
1.5×10 N (see figure). The length of the slider is 30 cm and its weight negligible the surface
tension of the liquid film is ::
(1) 0.025 N/m
3.
(2) 4TD2
(3) TD2
(4) None of these
The excess pressure inside an air bubble of radius r just below the surface of water is p1. The
excess pressure inside a drop of the same radius just outside the surface is p2. If T is surface
tension, then
(1) p1 = 2P2
5.
(4) 0.05 N/m
A liquid drop of diameter D breaks into 27 tiny drops. The resultant change in energy is
is-
(1) 2TD2
4.
(2) 0.0125 N/m (3) 0.1 N/m
(2) p1 = P2
(3) P2 = 2p1
(4) P2 = 0, P1  0
A water drop is divided into 8 equal droplets. The pressure difference between inner and
a outer
sides of the big drop
(1) will be the same as for smaller droplet
(2) will be half of that for smaller droplet
(3) will be one-forth
forth of that for smaller droplet
(4) will be twice of that for smaller droplet.
6.
A false statement is:
(1) Angle of contact  < 90°, if cohesive : force < adhesive force × 2
(2) Angle of contact  > 90°, if cohesive force > adhesive force × 2
(3) Angle of contact  = 90°, if cohesive force = adhesive force × 2
(4) If the radius of capillary is reduced to half, the rise of liquid column becomes four times.
7.
If a capillary of radius r is dipped in water, the height of water that rises in it is hand its mass is
M. If the radius of the capillary is doubled the mass of water that rises in the capillary will be
(1) 4M
8.
(2) 2M
(3) M
(4)
M
2
On dipping a capillary of radius 'r' in water, water rises up to a height H and potential energy of
water is u1. If a capillary of radius 2r is dipped in water, then the potential energy is u2. The ratio
u1
is
u2
(1) 2 : 1
9.
(2) 1 : 2
(3) 4 : l
(4) 1 : 1
A vessel, whose bottom has round holes with diameter of 0.1 mm, is filled with water. The
maximum height to which the water can be filled without leakage is :(S.T. of water = 75 dyne/cm, g = 1000 cm/s2)
(l) 100 cm
10.
(2) 75 cm
(3) 50 cm
(4) 30 cm
In a surface tension experiment with a capillary tube water rises up to 0.1 m. If the same
experiment is repeated on an artificial satellite which is revolving round the earth, water will rise
in the capillary tube up to a height of
(1) 0.1m
(2) 0.98 m
(3) 9.8m
(4) full length of capillary tube
Answer
1.
(1)
2.
(1)
3.
(1)
4.
(2)
7.
(2)
8.
(4)
9.
(4)
10.
(4)
5.
(2)
6.
(4)
Hooks Law
1.
The Young's modulus of a rubber string 8 cm long and density 1.5 kg/m3 is 5 × 108 N/m2, is
suspended on the ceiling in a room. The increase in length due to its own weight will be :
(1) 9.6 × 10–5 m (2) 9.6 × 10–11 m
2.
3.
A ball falling in a lake of depth 200m shows 0.1% decrease in its volume at the bottom. What is
the bulk modulus of the material of the ball :
(1) 19.6 × 108 N/m2
(2) 19.6 × 10–10 N/m2
(3) 19.6 × 1010 N/m2
(4) 19.6 × 10–8 N/m2
The pressure of a medium is changed from 1.01×105 Pa to 1.165×105 Pa and change in volume is
10% keeping temperature constant. The bulk modulus of the medium is :(1) 204.8 × 105 Pa
4.
(2) 102.4 × 105 Pa
(2) 4 : 1
(4) 1: 1
(4) attains a value 0 K
A mass of 0.5 kg is suspended from wire, then length of wire increase by 3 mm then find out
work done :
(1) 4.5 × 103 J
(2) 7.3 × 103 J
(3) 9.3 × 10–2 J
(4) 2.5 × 10–2 J
If the strain in a wire is not more than 1/1000 and Y = 2 × 1011 N/m2, Diameter of wire is 1 mm.
The modulus of brass is 9 × 1010 N/m2. The force maximum weight hung from the wire is:required to stretch by 0.1% of its length is :
(1) 110 N
8.
(3) 2 : 1
(2) falls
(3) remains unchanged
7.
(4) 1.55 × 105 Pa
A weight is suspended from a long metal wire. If the wire suddenly breaks, its temperature
(1) rises
6.
(3) 51.2 × 105 Pa
Two wires of the same material and length but diameters in the ratio 1 : 2 are stretched by the
same force. The potential energy per unit volume for the two wires when stretched will be in
the ratio.
(1) 16 : 1
5.
(3) 9.6 × 10–3m (4) 9.6m
(2) 125 N
(3) 157 N
(4) 168 N
When a tension F is applied in uniform wire of length  and radius r, the elongation produced is
e. When tension 2F is applied, the elongation produced in another uniform wire of length 2 and
radius 2r made of same material is :-
(1) 0.5 e
9.
(2) 1.0 e
(3) 1.5 e
(4) 2.0 e
How much force is required to produce an increase of 0.2% in the length of a brass wire of
diameter 0.6mm?
[Young's modulus for brass= 0.9 × 1011 N/m2]
10.
(1) Nearly 17 N
(2) Nearly 34 N
(3) Nearly 51 N
(4) Nearly 68 N
If the interatomic spacing in a steel wire is 2.8 × 10–10 m and Y = 2 × 1011 N/m2 then steel force
constant in N/m is(1) 5.6
(2) 56
(3) 0.56
(4) 560
Answer
8.
(2)
9.
(1)
10.
(4)
11.
(1)
14.
(3)
15.
(2)
16.
(3)
17.
(2)
12.
(1)
13.
(2)
Variation of Pressure & Pascals
Pasc Law
1.
The spring balance A read 2 kg. with a block m suspended from it. A balance B reads 5 kg. when
nce. The two balances are now so arranged that
a beaker with liquid is put on the pan of the bala
balance.
:
the hanging mass is inside the liquid in the beaker as shown in figure. In this situation :-
(1) The balance A will read more than 2 kg.
k
(2) The balance B will read more' than 5 kg.
(3) The balance A will read less than 2kg. and B will read more than 5 kg.
(4) The balance
ce A and B will read 2 kg. and 5 kg. respectively.
2.
A jar is filled with two non
non-mixing liquids 1 and 2 having densities 1 and 2, respectively
A solid ball, made of a material of density 3 , is dropped in. the jar. It comes to equilibrium in
the position shown in the figure: Which of the following is true for 1, 2 & 3
3.
(1) 3 < 1 < 2
(2) 1 > 3 > 2
(3) 1 < 2 < 3
(4) 1 < 3 < 2
A boat having a length of 3 mete
meter and breadth 2 meter floating on a lake. The boat sinks by one
cm where a man gets on it. The mass of the man is
(1) 60 kg
(2) 62 kg
(3) 72 kg
(4) 128 kg
4.
If the density of a block is 981 kg/m3 then it shall
(1) Sink in water
(2) float with some part emmersed in water
(3) float completely immersed in water
(4) float completely out of water.
5.
A wooden block, with a coin placed on its, floats in water as shown in figure. The distance  and
h are shown there. After sometime the coin falls into the water. Then:Then:
(1)  decreases and h increases
increa
(3) both  and h increase
rease
6.
(4) both  arid h decrease
A piece of ice is floating in a jar containing
conta
water. When the ice melts, then the level of water ::
(l) Rises
(2) Falls
(3) Remains unchanged
7.
(2)  increases and h decreases
(4) Changes, erratically
A sample of metal weights 210 gram in air, 180 gram in water and 120 gram in an unknown
liquid. Then :-
(1) the density of metal is 3 g/cm3
(2) the density of metal is 7 g/ cm3
(3) density of metal is 4 times the density of the unknown liquid
(4) the metal will float in water
8.
'Torr' is the unit of:(1) Pressure
(2) Density
(3) Volume
(4) Flux
9.
A sphere is floating in water its 1/3rd part is outside the water and when sphere is floating in
unknown
3
th liquid, its part is outside the liquid then density of liquid is
4
(1) 4/9 gm/c.c. (2) 9/4 gm/c.c.
10.
(3) 8/3 gm/c.c. (4) 3/8 gm/c.c.
Which of the following works on Pascal's law?
(1) Sprayer
(2) Venturimeter
(3) Hydraulic lift
(4) Aneroid barometer
3.
(1)
4.
(2)
5.
(4)
(2)
8.
(1)
9.
(3)
10.
Answer
1.
(3)
2.
6.(3)
(4)
7.
(3)
Bernoulli’s
1`
A tank of height 5 m is full of water. There is a hole of cross sectional area 1 cm2 in its bottom.
The initial volume of water that will come out from this hole per second is
(1) 10–3 m3/s
(2) 104 m3/s
(3) 10 m3/s
(4) 10–2 m3/s.
2.
The pressure of water in a water pipe when tap is opened and closed is respectively 3 × 105
N/m2 and 3.5 × 105 N/m2. With open tap, the velocity of water flowing is
(1) 10 m/s
3.
(2) 5 m/s
(3) 20 m/s
(4) 15m/s
The flow speeds of air on the lower and upper surfaces of the wing of an aeroplane are v and
2v respectively. The density of air is p and surface area of wing is A The dynamic lift on the
wing is :
4.
(1) v2A
(2)
2 v2
(3) (1/2) v2A
(4) 2v2A
An incompressible fluid flows steadily through a cylindrical pipe which has radius 2 Rat point A
and radius Rat point B farther along the flow direction. If the velocity at point A is v, its velocity
at point height h in air. The final velocity is B is:(1) 2v
(2) v
(3)
v
2
(4) 4v
5.
Water is flowing through a non-uniform radius tube. If ratio of the radius of entry and exit end
of the pipe is 3 : 2 then the ratio of velocities of entring and exit liquid is:(1) 4 : 9
6.
(2) 9 : 4
(3) 8 : 27
(4) 1 : 1
An aeroplane of mass 3×104 kg and total wing area of 120 m is in a level flight at some height.
The difference in pressure between the upper and lower surfaces of its wings in kilopascals is
(g =10m/s2)
(1) 2.5
7.
8.
(2) 5.0
(3) 10.0
(4) 12.5
Scent sprayer is based on
(1) Charle's law
(2) Archimede's principle
(3) Boyle's law
(4) Bernoulli's theorem
Bernoulli's equation for steady, non-viscous, in compressible flow expresses the
(1) Conservation of angular momentum (2) Conservation of density
(3) Conservation of momentum
9.
10.
(4) Conservation of mechanical energy.
Application of Bernoulli's theorem can be seen in
(1) Dynamic lift to aeroplane
(2) Hydraulic press
(3) Speed Boat
(4) None of these
The velocity of water flowing in a non-uniform tube is 20 cm/s at a point where the tube radius
is 0.2 cm. The velocity at another point, where the radius is 0.1 cm is
(1) 80 cm/s
(2) 40 cm/s
(3) 20 cm/s
(4) 5 cm/s
Answer
1.
(1)
2.
(1)
3.
(3)
4.
(4)
7.
(4)
8.
(4)
9.
(1)
10.
(1)
5.
(1)
6.
(1)