Phy – Chapter 5: Work, Energy and Power

1

If the velocity of an object is doubled, its kinetic energy becomes:

A Half B Double C Four times D Unchanged

2

According to the law of conservation of energy, energy can be:

A Created but not destroyed B Destroyed but not created C Neither created nor destroyed D Created and destroyed

3

The kinetic energy of a moving object depends on its:

A Mass only B Speed only C Mass and speed D Mass and height

4

If a machine does 100 J of work in 5 seconds, its power is:

A 20 W B 50 W C 100 W D 500 W

5

A force of 10 N acts on a body and moves it 2 m in the direction of force. What is the work done?

A 5 J B 10 J C 20 J D 40 J

6

According to the law of conservation of energy, energy can:

A Be created but not destroyed B Be destroyed but not created C Neither be created nor destroyed D Be created and destroyed

7

The work-energy theorem states that work done on a body equals the change in its:

A Potential energy B Kinetic energy C Total energy D Power

8

The power of a body is defined as the rate of doing:

A Work B Energy C Force D Momentum

9

In a simple pendulum, at the mean position, the energy is:

A Entirely potential B Entirely kinetic C Half potential and half kinetic D Zero

10

Which of the following is the SI unit of power?

A Joule B Newton C Watt D Pascal

11

The unit of power is:

A Joule B Watt C Newton D Pascal

12

In a hydroelectric power plant, the energy of flowing water is converted into:

A Chemical energy B Nuclear energy C Electrical energy D Solar energy

13

When a force of 10 N acts on a body and moves it 2 m in the direction of the force, the work done is:

A 5 J B 10 J C 20 J D 40 J

14

The efficiency of a machine is 80%. If it receives 500 J of energy, how much useful work is done?

A 100 J B 400 J C 500 J D 625 J

15

A force of 10 N acts on a body and moves it 5 m in the direction of the force. What is the work done?

A 2 J B 5 J C 50 J D 0.5 J

16

The SI unit of power is:

A Joule B Newton C Watt D Pascal

17

Efficiency of a machine is given by:

A Output energy / Input energy × 100 B Input energy / Output energy × 100 C Work / Time D Force × Distance

18

Which of the following is a non-renewable source of energy?

A Solar energy B Wind energy C Fossil fuels D Geothermal energy

19

Power is defined as the rate of doing work. Its SI unit is:

A Joule B Watt C Newton D Second

20

The energy possessed by a body due to its position is called:

A Kinetic energy B Potential energy C Thermal energy D Chemical energy

21

When a force of 1 N displaces an object by 1 m in the direction of force, the work done is:

A 1 J B 1 W C 1 N D 1 Pa

22

In a simple pendulum, the energy at the mean position is:

A Entirely potential B Entirely kinetic C Half kinetic and half potential D Zero

23

Which of the following is a fossil fuel?

A Wood B Coal C Biogas D Hydrogen

24

The energy stored in the nucleus of an atom is called:

A Nuclear energy B Chemical energy C Geothermal energy D Tidal energy

25

Which energy source is considered non-renewable?

A Wind B Solar C Coal D Geothermal