Work, Energy and Power Quiz - CBSE Class 11 Science

Free practice quiz: Work, Energy and Power (CBSE Class 11 Science). 18 multiple-choice questions with answers and explanations. Play online, no sign-up needed.

This CBSE Class 11 Science practice quiz has 18 multiple-choice questions on Work, Energy and Power, and 18 of them come with an explanation. Try the 5 sample questions below (tap an option to check yourself), then play the full quiz online. No sign-up needed.

Sample questions

1. A force of 10 N acts on an object causing it to move 5 meters in the direction of the force. What is the work done?

   1. 0 J
   2. 50 J
   3. 5 J
   4. 100 J
   Show answer

   Answer: B. 50 J

   Work done = Force × Distance × cos(θ), where θ is the angle between the force and displacement. Since the force and displacement are in the same direction, θ = 0°, and cos(0°) = 1. Therefore, Work done = 10 N × 5 m = 50 J.

2. What is power?

   1. The rate of doing work
   2. The amount of work done
   3. The force applied
   4. The distance moved
   Show answer

   Answer: A. The rate of doing work

   Power is the rate at which work is done or energy is transferred.

3. State the work-energy theorem.

   1. Work done = change in potential energy
   2. Work done = change in kinetic energy
   3. Work done = potential energy + kinetic energy
   4. Work done = force x displacement
   Show answer

   Answer: B. Work done = change in kinetic energy

   The work-energy theorem states that the net work done on an object is equal to the change in its kinetic energy.

4. What is the efficiency of a machine that does 100 J of useful work when 200 J of energy is supplied to it?

   1. 50%
   2. 100%
   3. 200%
   4. 0%
   Show answer

   Answer: A. 50%

   Efficiency = (Useful work output / Energy input) × 100% = (100 J / 200 J) × 100% = 50%

5. A pendulum swings back and forth. Describe the energy transformations that occur during one complete swing, neglecting air resistance.

   1. Potential energy is converted to kinetic energy and back again
   2. Kinetic energy is converted to potential energy and back again
   3. Both potential and kinetic energies remain constant
   4. Only kinetic energy is involved
   Show answer

   Answer: A. Potential energy is converted to kinetic energy and back again

   At the highest point of its swing, the pendulum has maximum potential energy and minimum kinetic energy. As it swings down, potential energy converts to kinetic energy, reaching maximum kinetic energy at the bottom. As it swings back up, kinetic energy converts back to potential energy.

More questions in this quiz

Answers and explanations are in the full quiz.

1. What is the SI unit of energy?
2. A machine lifts a 100 kg mass to a height of 2 meters. Calculate the potential energy gained by the mass (assuming g = 10 m/s²).
3. A 60W light bulb is left on for 5 hours. How much energy does it consume?
4. What is kinetic energy?
5. A car of mass 1000 kg is moving with a velocity of 20 m/s. Calculate its kinetic energy.
6. A ball is thrown vertically upwards. At its highest point, what type of energy does it possess?
7. A roller coaster car starts from rest at the top of a hill. Ignoring friction, what happens to its potential energy as it descends?
8. Explain the concept of power and its relationship with work and time.
9. A 1500 kg car accelerates from rest to 30 m/s in 10 seconds. Calculate the average power delivered by the engine (ignore friction).
10. Discuss the different forms of energy and give examples of their conversion from one form to another.
11. Derive the expression for the escape velocity of an object from the surface of a planet of mass M and radius R.
12. A complex system involves multiple energy transformations and losses due to friction and other non-conservative forces. Explain how you would approach calculating the overall efficiency of such a system.
13. Discuss the limitations of the concept of mechanical energy conservation in real-world scenarios.

More quizzes

• Force and Laws of Motion▶ Play
• Gravitation▶ Play
• Kinetic Theory▶ Play
• Motion in a Straight Line▶ Play
• Properties of Bulk Matter▶ Play
• Thermodynamics▶ Play

Browse all Physical Science quizzes

More to play