CBSE Class 11-Physics: Work Energy and Power Assignment 1 (For CBSE, ICSE, IAS, NET, NRA 2022)

Glide to success with Doorsteptutor material for CBSE : fully solved questions with step-by-step explanation- practice your way to success.

Question 1:

A peculiar spring has a force law

which of the following is true?

(a) Potential energy at point when at is

(b) If a mass m is attached to the spring. Mass is displaced slightly, it will follow simple harmonic motion

(c) work must be done on the spring in stretching it slowing from to

(d) None of the above

Answer:

(a) , (c)

Question 2

An object of mass M slides downward along a plane inclined at angle . The coefficient of friction is

Find

(a)

(b)

(c)

(d) None of the above

Answer:

(a)

Question 3

What is true for gravitational force

(a) Work done between the two points does not depend on the path travelled

(b) Work done in a closed loop is zero

(c)

(d) It is a conservative force

Answer:

(a) , (b) , (c) , (d)

Question 4

An object moves on an inclined plane in upward direction at uniform velocity. Neglect frictional force. Which of the following is true?

(a) Gravitational force does negative work

(b) Engine does positive work

(c) Normal reaction force does not do any work

(d) None of the above

Answer:

(a) , (b) , (c)

Question 5

If F is the conservative force, U is potential energy associated with this force and dr … is displacement. Which of the following is true?

(a)

(b)

(c)

(d) None of the above

Answer:

(a)

(c)

Question 6

A body is moving along positive axis at and It is subjected to retarded force

Find the x coordinate, where 0

(a)

(b)

(c)

(d) None of the above

Answer:

(a)

Question 7

A particle moves from rest at point on the surface of the smooth circular cylinder of radius R

Find the angle it will leave the cylinder

(a)

(b)

(c)

(d) None of the above

Answer:

(c)

Question 8:

The kinetic energy of a particle moving along a circle of radius R depend on the distance covered S as

where a is constant find the force acting on the particle as a function of S

(a)

(b)

(c)

(d) None of the above

Answer:

(b)

Question 9

A body is thrown vertically upward with a velocity v. It rises to some height and come back. find the mean power over all cycle

(a)

(b)

(c)

(d) None of the above

Answer:

(b)