NCERT Class-9 Science Solutions: Chapter 11-Work and Energy Part 1 (For CBSE, ICSE, IAS, NET, NRA 2023)

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Multiple Choice Questions

Question 1:

When a body falls freely towards the earth, then its total energy

  1. Increases
  2. Decreases
  3. Remains constant
  4. First increases and then decreases

Answer: C

Image the Moon Toward the Earth

Question 2:

A car is accelerated on a levelled road and attains a velocity of its initial velocity. In this process the potential energy of the car

  1. Does not change
  2. Becomes twice to that of initial
  3. Becomes 4 times that of initial
  4. Becomes 16 times that of initial

Answer: A

Question 3:

In case of negative work the angle between the force and displacement is

Answer: D

Image the Force and Displacement

Question 4:

An iron sphere of mass has the same diameter as an aluminum sphere of mass is . Both spheres are dropped simultaneously from a tower. When they are above the ground, they have the same

  1. Acceleration
  2. Momenta
  3. Potential energy
  4. Kinetic energy

Answer: A

Gravity Equation Free Fall Acceleration of Body

Question 5:

A girl is carrying a school bag of mass on her back and moves on a levelled road. The work done against the gravitational force will be

Answer: D

Work Done Against the Gravitational Force

Question 6:

Which one of the following is not the unit of energy?

  1. Joule
  2. Kilowatt-hour
  3. Newton meter
  4. kilowatt

Answer: C

Question 7:

The work done on an object does not depend upon the

  1. Displacement
  2. Force applied
  3. Angle between force and displacement
  4. Initial velocity of the object

Answer: D

Image the Initial Velocity of the Object