NCERT Class 11 Chapter 6 Physics Work, Energy and Power MCQ

NCERT Class 11 Chapter 6 Physics Work, Energy and Power MCQ | Questions & Answers: Here is a wonderful opportunity for the students of Class 11 where they can improve their knowledge regarding the Class 11 Chapter 6 Physics Work, Energy, and Power topic. Test yourselves with the below questions and learn about the correct answers so that you can improve and enhance your existing knowledge thoroughly.

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1. According to work-energy theorem, the work done by the net force on a particle is equal to the change in its

A. kinetic energy

B. angular momentum

C. linear momentum

D. potential energy

2. A light and a heavy body have equal momentum. Which one has greater K.E.?

A. The lighter body

B. The heavier body

C. Both have equal K.E.

D. Data given is incomplete

3. Kinetic energy, with any reference, must be

A. positive

B. zero

C. negative

D. None of these

4. Work done by a conservative force is positive if

A. P.E. of the body decreases

B. K.E. of the body increases

C. K.E. of the body decreases

D. P.E. of the body increases

5. The ...X... energy V(x) of the spring is said to be zero when block and spring system is in the ...Y... position. Here, X and Y refer to

A. potential, equilibrium

B. kinetic, equilibrium

C. mechanical, equilibrium

D. vibrational, left

6. Which of the following must be known in order to determine the power output of an automobile?

A. Work performed and elapsed time of work

B. Force exerted and distance of motion

C. Mass and amount of work performed

D. Final velocity and height

7. A vehicle is moving with a uniform velocity on a smooth horizontal road, then power delivered by its engine must be

A. increasing

B. zero

C. uniform

D. decreasing

8. How much water, a pump of 2 kW can raise in one minute to a height of 10 m, take g = 10 m/s²?

A. 1200

B. 100

C. 2000

D. 1000

9. The engine of a vehicle delivers constant power. If the vehicle is moving up the inclined plane then, its velocity

A. must remain constant

B. must increase

C. must decrease

D. may increase, decrease or remain same

10. A body projected vertically from the earth reaches a height equal to earth's radius before returning to the earth. The power exerted by the gravitational force is greatest

A. at the instant just before the body hits the earth

B. at the highest position of the body

C. it remains constant all through

D. at the instant just after the body is projected

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11. When the force retards the motion of body, the work done is

A. negative

B. zero

C. positive

D. None of these

12. A man pushes a wall and fails to displace it, he does

A. no work at all

B. positive but not maximum work

C. negative work

D. maximum positive work

13. A boy carrying a box on his head is walking on a level road from one place to another is doing no work. This statement is

A. correct

B. incorrect

C. partly correct

D. cannot say

14. No work is done if

A. All of these

B. force and displacement are mutually perpendicular

C. force is zero

D. displacement is zero

15. A particle is taken round a circle by application of force. The work done by the force is

A. Zero

B. positive non–zero

C. negative non–zero

D. None of these

16. Assertion : The work done in moving a body over a closed loop is zero for every force in nature.
Reason : Work done depends on nature of force

A. Assertion is correct, reason is correct; reason is not a correct explanation for assertion

B. Assertion is correct, reason is incorrect

C. Assertion is incorrect, reason is correct.

D. Assertion is correct, reason is correct; reason is a correct explanation for assertion

17. If a motorcyclist skids and stops after covering a distance of 15 m. The stopping force acting on the motorcycle by the road is 100 N, then the work done by the motorcycle on the road is

A. Zero

B. 750J

C. –1500 J

D. 1500 J

18. A ball moves in a frictionless inclined table without slipping. The work done by the table surface on the ball is

A. zero

B. positive

C. negative

D. None of these

19. A spring of spring constant 5 × 103 N/m is stretched initially by 5 cm from the unstretched position. Then the work required to stretch it further by another 5 cm is

A. 18.75 J

B. 25.00 J

C. 6.25 J

D. 12.50 J

20. A boy pushes a toy box 2.0 m along the floor by means of a force of 10 N directed downward at an angle of 60º to the horizontal. The work done by the boy is

A. 10 J

B. 12 J

C. 8 J

D. 6 J

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21. When a force of 50 N acts on a body, the body is displaced through a distance of 3 m in a direction normal to the direction of the force. The work done by the force

A. 150 J

B. 1470 J

C. Zero

D. -150 J

22. A body of mass 20 kg is initially at a height of 3 m above the ground. It is lifted to a height of 2 m from that position. Its increase in potential energy is

A. 100 J

B. 392 J

C. 60 J

D. -100 J

23. A wooden cube having mass 10 kg is dropped from the top of a building . After 1 s, a bullet of mass 20 g fired at it from the ground hits the block with a velocity of 1000 m/s at an angle of 30° to the horizontal moving upwards and gets imbedded in the block . The velocity of the block/bullet system immediately after the collision is

A. 17 m/s

B. 27 m/s

C. 52 m/s

D. 10 m/s

24. A body of mass 10 kg is moved parallel to the ground, through a distance of 2 m. The work done against gravitational force is

A. 196 J

B. -196 J

C. 20 J

D. zero

25. A quantity of work of 1000 J is done in 2 seconds. The power utilised is

A. 998 W

B. 1002 W

C. 2000 W

D. 500 W