1. The capacity of a body to do
work is called-
(a) Energy
(b) Power
(c) Force
(d) Velocity
ANS: Energy
2. Which is the renewable
source of energy among the following-
(a) Coal
(b) Natural gas
(c) Sun
(d) Fossil fuels
ANS: Sun
3. The unit of work is joule.
The other physical quantity that has same unit is-
(a) power
(b) velocity
(c) energy
(d) force
ANS: energy
4.
1 Joule = ______ erg.
(a) 107
(b) 105
(c) 10-7
(d) 10-5
ANS: 107
5. 1 erg = _____ Joule.
(a) 107
(b) 105
(c) 10-7
(d) 10-5
ANS: 10-7
6.
1 J = ______ x 10 m
(a) 1 s
(b) 1 N
(c) 10-1 s
(d) 10-1 N
ANS: 10-1 N
7.
Which one of the following is not the unit of energy?
(a) joule
(b) newton metre
(c) kilowatt
(d) kilowatt hour
ANS: kilowatt
8.
Which one of the following is not the unit of energy?
(a) joule
(b) newton per metre
(c) electron-volt
(d) kilowatt hour
ANS: newton per metre
(electron-volt or eV is a unit of
energy)
9.
1 MeV (Mega electron volt) is equal to-
(a) 1.6 x 1013 J
(b) 1.6 x 10-19 J
(c) 1.6 x 1019 J
(d) 1.6 x 10-13 J
ANS: 1.6 x 10-13 J
10. The energy of a body due to
its motion is called-
(a) gravitational energy
(b) static energy
(c) kinetic energy
(d) all of these
ANS: kinetic energy
11.
An object of mass ‘m’ moving with a velocity ‘v’ has a kinetic energy of-
(a) ½ mv2
(b) mgh
(c) 2mv2
(d) 4mv2
ANS: ½ mv2
12. Kinetic energy of a body
depends-
(a) on its mass only
(b) on its velocity only
(c) on its mass as well as on
its velocity
(d) neither on its mass nor on
its velocity
ANS: on its mass as well as on its
velocity
13.
The kinetic energy of an object is K. If its mass is reduced to half,
then its kinetic energy will be-
(a) K
(b) K/2
(c) 2K
(d) K/4
ANS: K/2
14. The kinetic energy of an
object is K. If its velocity is doubled, then its kinetic energy will be-
(a) 2K
(b) K/2
(c) 4K
(d) K/4
ANS: 4K
15.
The kinetic energy of a body is increased most by doubling its-
(a) mass
(b) weight
(c) velocity
(d) density
ANS: velocity
16.
Kinetic energy of a body becomes double if-
(a) its mass and velocity are
doubled
(b) its mass remains the same but its
velocity is doubled
(c) its mass is doubled and its
velocity remains the same
(d) its mass remains the same
but its velocity is reduced to half
ANS: its mass is doubled and its
velocity remains the same
17.
When speed of the moving object is doubled its-
(a) acceleration is doubled
(b) momentum increases to four times
(c) K.E. becomes four times
(d) Potential energy gets
doubled
ANS: K.E. becomes four times
18.
On tripling the speed of motion of a body, the change in K.E. is-
(a) 9 times
(b) 8 times
(c) 4 times
(d) 2 times
ANS: 9 times
19.
The speed of a motor bike decreases by 4 times. Its kinetic energy will
decrease by-
(a) four times
(b) eight times
(c) sixteen times
(d) thirty-two times
ANS: sixteen times
20.
The work required to be done to stop a car of 2500 kg moving at a
velocity of 90 km/h is,
(a) -781.25 kJ
(b) 781.25 kJ
(c) 2250 kJ
(d) -2250 kJ
ANS: -781.25 kJ
21.
The mass of a ball A is twice the mass of another ball B. The ball A
moves at half the speed of the ball B. The ratio of the kinetic energy of A to
that of B is-
(a) 3:2
(b) 1:2
(c) 5:2
(d) 4:2
ANS: 1:2
22. Two bodies have their
masses m1/m2 = 3 and their kinetic energies K.E1/K.E2 = 1/3. The ratio of their
velocities is-
(a) 1:1
(b) 1:2
(c) 1:3
(d) 2:3
ANS: 1:3
23. Which of the following
graphs show variation of kinetic energy with speed?
ANS: (d)
24.
Which of the following graph correctly describes the variation of
kinetic energy with time of a block when it slides down a smooth inclined plane
from rest?
ANS: C
25.
The momentum of a bullet of mass 20 g fired from a gun is 10 kg m/s. The
kinetic energy of this bullet in kJ will be-
(a) 25
(b) 2.5
(c) 0.25
(d) 5
ANS: 2.5
26. The momentum of a body is-
(a) directly proportional to
velocity of the body, provided its mass remains constant
(b) directly proportional to the
mass of the body, provided its velocity remains constant
(c) inversely proportional to
the kinetic energy of the body
(d) both (a) and (b)
ANS: both (a) and (b)
27.
When the momentum of a body is increased by 100%, its K.E. increases by
(a) 100%
(b) 200%
(c) 300%
(d) 400%
ANS: 300%
28. A player transfers a
momentum of 12 kg m/s to a ball of mass 400 g which is at rest. Find the work
done on the ball-
(a) 180 J
(b) 345 J
(c) 400 J
(d) 427 J
ANS: 180 J
29. Two bodies of mass mA
and mB have equal kinetic energy. The ratio of their momenta is-
(a) mA : mB
(b) mA2 : mB2
(c) √mA : √mB
(d) mB : mA
ANS: √mA : √mB
30.
Two bodies of mass 2 g and 3 g have equal kinetic energy. Which of the
ratios of their momentum given below, is the correct one?
(a) 2:3
(b) 4:9
(c) 3:2
(d) √2 : √3
ANS: √2 : √3
31.
Two objects of masses 1 x 10-3 kg and 4 x 10-3 kg
have equal momentum. What is the ratio of their kinetic energies?
(a) 2:1
(b) 1:4
(c) 4:1
(d) 1:2
ANS: 4:1
32.
Which of the following graphs best represents graphical relation between
momentum P and kinetic energy K for a body in motion?
ANS: (d)
33. A body at rest can have-
(a) Energy
(b) Power
(c) Momentum
(d) Acceleration
ANS: energy
34.
Potential energy of a body depends on its-
(a) position
(b) configuration
(c) both position and
configuration
(d) mass and velocity
ANS: both position and configuration
35.
When a coil spring is compressed, the work is done on the spring. The
elastic potential energy-
(a) increases
(b) decreases
(c) disappears totally
(d) remains unchanged
ANS: increases
36.
When you stretch a coil spring you do work on it. The elastic P.E. of
the spring-
(a) remains unchanged
(b) decreases
(c) disappears
(d) increases
ANS: increases
37. P.E. of a spring increases,
when it is in the state of-
(a) compression
(b) expansion
(c) both (a) and (b)
(d) neither (a) nor (b)
ANS: both (a) and (b)
38.
Potential energy of a person is maximum when-
(a) person is sitting on a chair
(b) person is standing on the roof
(c) person is lying on the
ground
(d) person is sitting on the
ground
ANS: person is standing on the roof
39. Potential energy of your
body is minimum when you
(a) are standing
(b) are sitting on the chair
(c) are sitting on the ground
(d) lie down on the ground
ANS: lie down on the ground
40.
A stone is thrown vertically upward with a velocity v. The kinetic
energy at the highest point is-
(a) ½ mgh
(b) mgh
(c) ½ mv2
(d) zero
ANS: zero
41. A stone is thrown
vertically upward. It comes to rest momentarily at the highest point. What
happens to its kinetic energy?
(a) it converts into elastic
potential energy
(b) it converts into
gravitational potential energy
(c) it converts into chemical
energy
(d) it is completely destroyed
ANS: it converts into gravitational
potential energy
42.
A body at rest at a certain height possesses-
(a) kinetic energy
(b) gravitational potential energy
(c) elastic potential energy
(d) heat energy
ANS: gravitational potential energy
43.
The gravitational potential energy of an object of mass ‘m’ raised
through a height ‘h’ from the earth’s surface is given by-
(a) ½ mgh
(b) mgh
(c) 2mv2
(d) Zero
ANS: mgh
44. The gravitational potential
energy of an object is due to-
(a) its mass
(b) its acceleration due to
gravity
(c) its height above the earth’s
surface
(d) all the above
ANS: all the above
45.
A man of mass 50 kg jumps to a height of 1 m. His potential energy at
the highest point is (g = 10 m/s2)-
(a) 5 J
(b) 50 J
(c) 500 J
(d) 5000 J
ANS: 500 J
46.
Two bodies of equal weight are kept at heights of h and 1.5 h
respectively. The ratio of their potential energies is-
(a) 3:2
(b) 2:3
(c) 1:1
(d) 4:3
ANS: 2:3
47. A ball is dropped from the
roof of a tower of height ‘h’. The velocity of the ball when it reaches the
ground is 10 m/s. Find the height of the tower. (g = 10 ms-2)
(a) 5.6 m
(b) 12 m
(c) 5 m
(d) 10 m
ANS: 5 m
48. An object of mass 1 kg has
a P.E. of 1 Joule relative to the ground when it is at a height of-
(a) 0.102 m
(b) 1 m
(c) 9.8 m
(d) 32 m
ANS: 0.102 m (calculate h using the
relation, P.E. = mgh)
49. 9800 Joule of energy was
spent to raise a mass of 50 kg. The mass was raised to a height of-
(a) 20 m
(b) 980 m
(c) 10 m
(d) none of the above
ANS: 20 m
50. Which of the following is
not a stored form of energy?
(a) chemical energy
(b) gravitational potential
energy
(c) kinetic energy
(d) elastic potential energy
ANS: kinetic energy
51.
Which of the following is not an example of potential energy?
(a) water stored in a dam
(b) a stretched bow and arrow system
(c) a dog chasing a hare
(d) a stone lying on the top of
a roof
ANS: a dog chasing a hare
52.
A car is accelerated on a levelled road and attains a velocity 4 times
of its initial velocity. In this process the potential energy of the car
(a) does not change
(b) becomes twice to that of initial
(c) becomes 4 times that of
initial
(d) becomes 16 times that of
initial
ANS: does not change
53. A girl is carrying a school
bag of 3 kg mass on her back and moves 200 m on a levelled road. The work done
against the gravitational force will be (g=10 m/s2)
(a) 6 x 103 J
(b) 6 J
(c) 0.6 J
(d) Zero
ANS: zero
54.
A rocket rises vertically. What happens to its potential energy?
(a) it increases
(b) it initially increases then
decreases
(c) it initially decreases then
increases
(d) it increases, till it
becomes maximum
ANS: it increases, till it becomes
maximum
55. Mechanical energy of a body
includes-
(a) kinetic energy only
(b) potential energy only
(c) both kinetic energy and
potential energy
(d) none of these
ANS: both kinetic energy and
potential energy
56. The energy possessed by an
oscillating pendulum of a clock is-
(a) kinetic energy
(b) potential energy
(c) mechanical energy
(d) sound energy
ANS: mechanical energy
57.
The type of energy possessed by a simple pendulum, when it is at the
mean position is-
(a) kinetic energy
(b) potential energy
(c) kinetic + potential energy
(d) sound energy
ANS: kinetic energy
58.
The type of energy possessed by a simple pendulum, when it is at the
extreme position is-
(a) kinetic energy
(b) potential energy
(c) kinetic + potential energy
(d) sound energy
ANS: potential energy
59.
The form of energy possessed by a flying bird/ flying aeroplane is-
(a) kinetic energy
(b) potential energy
(c) both kinetic and potential
energy
(d) zero
ANS: both kinetic and potential
energy
60. When a body rolls down an
inclined plane, then it has-
(a) kinetic energy
(b) potential energy
(c) both kinetic and potential
energy
(d) zero
ANS: both kinetic and potential
energy
61.
According to the law of conservation of energy-
(a) energy can’t be destroyed
(b) energy can’t be created
(c) energy can be transformed
from one form to another
(d) all the above
ANS: All the above
62.
An iron sphere of mass 10 kg has the same diameter as an aluminium sphere
of mass is 3.5 kg. Both spheres are dropped simultaneously from a tower. When
they are 10 m above the ground, they have the same-
(a) acceleration
(b) momenta
(c) potential energy
(d) kinetic energy
ANS: acceleration
63. When a body falls freely
towards the earth, then its total energy-
(a) increases
(b) decreases
(c) remains constant
(d) first increases and then
decreases
ANS: remains constant
64. A mass ‘m’ falls from a
height ‘h’. The total energy at any point on its path is-
(a) ½ mgh
(b) mgh
(c) 3mgh
(d) 2mgh
ANS: mgh
65. A stone weighing 1 kg is
dropped from rest from a height of 4 metres above the ground. When it has
fallen 1 metre its total energy with respect to the ground is -
(a) 20 J
(b) 30 J
(c) 40 J
(d) 35 J
ANS: 40 J
66.
When a ball is dropped from a height of 10m-
(a) its potential energy
increases and kinetic energy decreases during the fall
(b) its potential energy is equal to
the kinetic energy during the fall
(c) the potential energy
decreases and kinetic energy increases during the fall
(d) the potential energy is zero
and kinetic energy is maximum while it is falling
ANS: the potential energy decreases
and kinetic energy increases during the fall
67. A body is falling from a
height h. After it has fallen a height h/2, it will possess
(a) only potential energy
(b) only kinetic energy
(c) half potential and half
kinetic energy
(d) more kinetic and less
potential energy
ANS: half potential and half kinetic
energy
68.
What happens to the kinetic energy of a freely falling object which
eventually stops on reaching the ground?
(a) It changes into heat &
sound energy
(b) It changes into electrical energy
(c) It changes into potential
energy
(d) None of the above
ANS: It changes into heat & sound
energy
69. When a stone of mass m
falls through a vertical height h, the decrease in the gravitational energy is
(a) mg2/h
(b) mgh
(c) mg/h2
(d) mg/2h
ANS: mgh
70. Person A reached the 2nd
floor of a hospital by lift and person B reached the same floor by stairs. If
both their masses are the same, then the-
(a) work done on A against the
gravitational force is greater than that done on B
(b) work done on B against the
gravitational force is greater than that done on A
(c) work done on them against
the gravitational force is the same
(d) power expended by both is
the same
ANS: work done on them against the
gravitational force is the same
71. Find the incorrect
statement.
(a) A body at rest may possess
energy
(b) K.E. is converted into heat
and sound energy when a freely falling body eventually stops on reaching the
ground
(c) The P.E. of a freely falling
body increases progressively
(d) There is no transfer of
energy between you and the rock when you push a huge rock and fail to move it
ANS: The P.E. of a freely falling
body increases progressively
72.
A microphone converts-
(a) sound energy into mechanical
energy in stereo system
(b) sound energy into electrical
energy in public address system
(c) electrical energy into sound
energy in ordinary telephone
(d) microwave energy into sound
energy in a mobile phone
ANS: sound energy into electrical
energy in public address system
73.
Heat energy is present in a body in the form of-
(a) infra-red radiation
(b) ultraviolet light
(c) kinetic energy of constituent particles
(d) none
ANS: kinetic energy of constituent
particles
74.
A stone rubbed on a rough surface and placed on the skin will show
heating sensation, because-
(a) friction causes heat
(b) heat flows from the skin to the
stone
(c) heat cannot flow
(d) the stone is heavy
ANS: friction causes heat
75. In winters, rubbing of hands
together for some time, causes a sensation of warmth mainly because of -
(a) heat caused by the force of
friction
(b) heat caused by the momentum
(c) heat caused by the motion
(d) heat flows from the blood
ANS: heat caused by the force of
friction.
76.
Which of the following energy change involves frictional change?
(a) potential energy to sound
energy
(b) chemical energy to heat energy
(c) kinetic energy to heat
energy
(d) chemical energy to heat
energy
Choose the correct option among the
following:
(a) both (i) and (ii)
(b) only (iv)
(c) both (ii) and (iii)
(d) only (iii)
ANS: only (iii)
77. Work done by friction-
(a) increases kinetic energy of
body
(b) decreases kinetic energy of
body
(c) increases potential energy
of body
(d) decreases potential energy
of body
ANS: decreases the kinetic energy of
body
78.
Water stored in a dam possesses-
(a) no energy
(b) electrical energy
(c) kinetic energy
(d) potential energy
ANS: potential energy
79.
In the dams water is stored in the high reservoirs and then made to fall
down. This falling water then rotates the turbines to generate electricity. In
this energy conversion process. Can you tell the initial and final energies
respectively?
(a) Kinetic energy and
electrical energy
(b) potential energy and kinetic
energy
(c) potential energy and
electrical energy
(d) kinetic energy and potential
energy
ANS: kinetic energy and electrical
energy
80. Which of the following best
describes the useful energy change that takes place inside a mobile phone when
sound is being produced?
(a) Electrical energy -> Sound
energy
(b) Chemical -> Electrical
energy -> Heat energy
(c) Chemical energy -> Heat
energy -> Electrical energy -> Sound energy
(d) Chemical energy ->
Electrical energy -> Sound energy
ANS: Chemical energy -> Electrical
energy -> Sound energy
81. _____ is the process in
which two or more atomic nuclei join to form a single heavier nucleus.
(a) nuclear fusion
(b) nuclear fission
(c) both (a) and (b)
(d) None of the above
ANS: nuclear fusion
82. A body falls freely from a height
of 10 m rebounds from a hard floor. It loses 20% of energy in the impact. What
is the height to which it would rise after the impact?
(a) 7 m
(b) 5 m
(c) 8 m
(d) 6 m
ANS: 8 m
83. Moon is the natural
satellite of the earth and weight of an object on the moon is one sixth times
the weight of same body on the earth. If a body is raised through height h on
the surface of earth and the energy spent is E, then for the same amount of energy
E the body on the surface of moon will rise through the height of-
(a) 2 h
(b) 6 h
(c) 4 h
(d) 12 h
ANS: 6 h
84.
Commercial unit of energy is-
(a) joule
(b) kWh
(c) watt
(d) newton
ANS: kWh
85. The number of joules
contained in 1 kWh is-
(a) 3.6 x 106 J
(b) 3.6 x 107 J
(c) 36 x 106 J
(d) 3.6 x 105 J
ANS: 3.6 x 106 J
