# Work Energy and Power MCQ Class 11 Physics

Please refer to Chapter 6 Work Energy and Power MCQ Class 11 Physics with answers below. These multiple-choice questions have been prepared based on the latest NCERT book for Class 11 Physics. Students should refer to MCQ Questions for Class 11 Physics with Answers to score more marks in Grade 11 Physics exams. Students should read the chapter Work Energy and Power and then attempt the following objective questions.

## MCQ Questions Class 11 Physics Chapter 6 Work Energy and Power

The Work Energy and Power MCQ Class 11 Physics provided below covers all important topics given in this chapter. These MCQs will help you to properly prepare for exams.

Question. 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

B

Question. A particle of mass m is moving in a horizontal circle of radius r under a centripetal force given by (-kr²) where k is a constant , then
(a) the total energy of the particle is (- k/2r)
(b) the kinetic energy of the particle is (k/r)
(c) the potential energy of the particle is (k/2r)
(d) the kinetic energy of the particle is (- k/r)

A

Question. 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

A

Question. A sphere of mass m moving with a constant velocity u hits another stationary sphere of the same mass. If e is the coefficient of restitution, then the ratio of velocity of the two spheres after the collision will be
(a) 1 – e / 1 + e
(b) 1 + e / 1 – e
(c) e + 1 / e – 1
(d) e – 1 / e + 1

A

Question. 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

D

Question. 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

C

Question. 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

D

Question. A marble moving with some velocity collides perfectly elastically head-on with another marble at rest having mass 1.5 times the mass of the colliding marble. The percentage of kinetic energy by the colliding marble after the collision is
(a) 4
(b) 25
(c) 44
(d) 67

A

Question. A body of mass 1 kg travels with a velocity of 10 m/s, this a wall and rebounds. If 50% of its initial energy is wasted as heat, its kinetic energy at the instant of rebounding is
(a) 20 J
(b) 60 J
(c) 50 J
(d) 25 J

D

Question. Two masses 1 g and 4 g are moving with equal kinetic energles. The ratio of the magnitudes of their linear momenta is
(a) 4 : 1
(b) 0 : 1
(c) 1 : 2
(d) 1 : 6

C

Question. 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

A

Question. A bullet fired into a fixed target loses half of its velocity after penetrating 3 cm. How much further will it penetrate before coming to rest assuming that it faces constant resistance to motion?
(a) 2.0 cm
(b) 3.0 cm
(c) 1.0 cm
(d) 1.5 cm

C

Question. A ball is dropped from a height of 1 m. If the coefficient of restitution between the surface and ball is 0.6, the ball rebounds to a height of
(a) 0.6 m
(b) 0.4 m
(c) 1 m
(d) 0.36 m

D

Question. A body of mass 5 kg is initially at a height of 10 m above the ground. It is then moved to another place 40 m from this position in the same horizontal level. Its increase in potential energy is
(a) 200 J
(b) 1960 J
(c) Zero
(d) -200 j

C

Question. An electric heater of rating 1000 W is used for 5 hrs per day for 20 days. The electrical energy utilised is
(a) 150 kWh
(b) 200 kWh
(c) 100 kWh
(d) 300 kWh

C

Question. A body of mass 20 kg falls vertically through a height of 10 m. Its loss of potential energy is
(a) 300 J
(b) 4000 J
(c) 1000 J
(d) 1960 J

D

Question. A body of mass 20 kg falls through a vertical height of 3 m. The work done by the gravitational force is
(a) -588 J
(b) 588 J
(c) 60 J
(d) -60 J

B

Question. A body of mass 10 kg is travelling with uniform speed of 5 m/s. Its kinetic energy is
(a) 25 J
(b) 125 J
(c) 1250 J
(d) 1000 J