Objective Type Questions On Class 11 Physics Chapter 6 Work Energy and Power

1 When a Cylinder Filled With Gas is Fitted With a Movable Piston is Allowed to Expand, Then the Work Done by the Gas is Positive. Identify the Statement True or False?

A True

B False

View Answer

Answer:True

2 The Work Done by the Centripetal Force for a Body Moving in a Circular Path is __________?

A Negative

B Zero

C Constant

D Positive

View Answer

Answer:Zero

3 When a Working Coolie Walks on a Horizontal Platform Having a Load on His Head, the Work Done by Him on the Load is Zero. Identify the Statement True or False?

A False

B True

View Answer

Answer:True

4 A Gardener Pushes a Lawn Roller Via a Distance of 20m. If He Applies a Force of 20kg Weight in a Direction Inclined at 60° to the Ground, Then What Will Be the Work Done by Him? (g=9.8m/s2)

A 400J

B 1960J

C 250J

D 2514J

View Answer

Answer:1960J

5 The Bullet That Has Fired from a Gun Can Pierce a Target Due to Its __________?

A Heat energy

B Mechanical energy

C Acceleration

D Kinetic energy

View Answer

Answer:Kinetic energy

6 A truck and car are moving with same Kinetic energies on a straight road.Their engines are simuktanously switched off .Which one will stop at a lesser distance

A Truck

B Car

C Both will stop at the same distance

D Cannot say with the given data

View Answer

Answer:Truck

7 A body of mass 1 kg is rotating in a circular path of radius 1 m with constant velocity of 5 rev/sec. The work done in one complete revolution is

A 5 J

B 2.5 J

C 12.5 J

D 0

View Answer

Answer:0

8 A loaf of Bread gives a boy of mass 40kg an energy of 21kJ. If the efficiency is 28% then the height can be climbed by him using this energy is

A 15 m

B 21 m

C 19.5m

D 15.5 m

View Answer

Answer:15 m

9 If the velocity of the object is increased by 0.1%, then the kinetic energy is increased by

A 0.1 %

B 0.2%

C 0.4%

D 0.01%

View Answer

Answer:0.2%

10 What is the smallest unit of power?

A Watt

B Kilowatt

C Horse power

D Milliwatt

View Answer

Answer:Watt

11 A body is falling freely under the action of gravity alone in vacuum.Which of the following quantities remain constant during the fall?

A Kinetic energy.

B Potential energy.

C Total mechanical energy.

D Total linear momentum.

View Answer

Answer:Total mechanical energy.

12 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

View Answer

Answer:25 J

13 A miner hauls up a load equal to his own weight from 50 meters depth upto the surface of the mine . The amount of work done by him is

A twice the work he dose in lifting himself up

B half the work he dose in lifting himself up

C Zero

D equal to the work he dose in lifting himself up

View Answer

Answer:twice the work he dose in lifting himself up

14 A body of mass 100 kg falls from a height of 10 m . Its increase in kinetic energy is

A 9800 J

B 1000 J

C 5000 J

D 3000 J

View Answer

Answer:9800 J

15 Consider the following two statements A : Linear momentum of a system of particles is zero B : Kinetic energy of a system of particles is zero . Then

A A implies B and B implies A .

B A implies B but B dose not imply A .

C A dose not imply B but B implies A .

D A dose not imply B and B dose not imply A .

View Answer

Answer:A dose not imply B but B implies A .

16 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

View Answer

Answer:500 W

17 A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table . The total mass of the chain is 4 kg . What is the work done in pulling the entire chain on the table ?

A 7.2 J

B 3.6 J

C 120 J

D 1200 J

View Answer

Answer:3.6 J

18 A small spherical ball is gently dropped from the rim of a hemispherical bowl with a smooth surface . The ball will

A rise up to the opposite rim of the bowl after reaching the bottom

B stop at the bottom of the bowl

C rise halfway up the bowl after reaching the bottom

D shoot out of the bowl through the opposite rim of the bowl

View Answer

Answer:rise up to the opposite rim of the bowl after reaching the bottom

19 A body of mass m moving with a velocity of 10 m/s makes an elastic collision with another body of same mass initially at rest . The first body comes at rest after the collision . Then the second mass will travel with a velocity of

A 10 m/s

B 5 m/s

C 20 m/s

D 15 m/s

View Answer