Work and Energy-MCQ

1.   The unit of work is joule. The other physical quantity that has same unit is

        (a) power         (b) velocity         (c) energy         (d) force

2.   The spring will have maximum potential energy when

        (a) it is pulled out         (b) it is compressed

        (c) both (a) and (b)         (d) neither (a) nor (b)

3.   The energy possessed by an oscillating pendulum of a clock is

        (a) kinetic energy         (b) potential energy

        (c) restoring energy.         (d) mechanical energy

4.   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 of the above.

5.   A ball is dropped from a height of 10 m.

        (a) Its potential energy increases and kinetic energy decreases during the falls

        (b) Its potential energy is equal to the kinetic energy during the fall.

        (c) The potential energy decreases and the kinetic energy increases during the fall.

        (d) The potential energy is �0� and kinetic energy is maximum while it is falling.

6.   If the velocity of a body is doubled its kinetic energy

        (a) gets doubled         (b) becomes half

        (c) does not change         (d) becomes 4 times

7.   How much time will be required to perform 520 J of work at the rate of 20 W?

        (a) 24s         (b) 16s         (c) 20 s         (d) 26 s

8.   A students caries a bag weighing 5 kg from the ground floor to his class on the first floor that is 2 m high. The work done by the boy is

        (a) 1 J         (b) 10 J         (c) 100 J         (d) 1000 J

9.   The work done is �O� if

        (a) The body shows displacement in the opposite direction of the force applied.

        (b) The body shows displacement in the same direction as that of the force applied.

        (c) The body shows a displacement in perpendicular direction to the force applied.

        (d) The body masses obliquely to the direction of the force applied.

10.   One unit of electrical energy is equal to

        (a) 3.6 � 10⁵J         (b) 3.6 � 10⁶J (c) 36 � 10⁵J         (d) both         (b) and (c)