Work, Energy and Power- Objective Questions


These Objective Questions on Work, Energy, and Power (Class XI, Physics) will help you in preparing for different examinations like AIEEE, AIPMT, IIT, and other +2 level competitive exams, and will also help in many government exams that ask the basics of physics.

1. When the momentum of a body increases by 200%, its KE increases by how much percent?

  • 100
  • 200
  • 400
  • 800
Click for Answer/Explanation

800

2. Two bodies of masses m1 and m2 are moving with the same kinetic energy. If P1 and P2 are their respective momentum, the ratio P1 P2 is equal to –

  • m1/m2
  • sqrt(m1/m2)
  • sqrt(m2/m1)
  • m2/m1
Click for Answer/Explanation

sqrt(m1/m2)

3. KE acquired by a mass m in traveling a certain distance d, starting from rest, under the action of a constant force F is?

  • Directly proportional to m
  • Directly proportional to vm
  • Directly proportional to 1/m
  • None of these
Click for Answer/Explanation

None of these

Read More ⇒ Physics: What is Projectile Motion

4. A simple pendulum with the bob of mass m and length x is held in position at an angle θ1 and then angle θ2 with the vertical. When released from these positions, speeds with which it passes the lowest positions are v1 & v2 respectively. Then, v1/v2 is-

  • 1-cos θ1/1-cos θ2
  • sqrt(1-cos θ1/1-cos θ2)
  • sqrt(2gx(1-cos θ1)/1-cos θ2)
  • sqrt((1-cos θ1)/2gx(1-cos θ2))
Click for Answer/Explanation

sqrt(1-cos θ1/1-cos θ2)

5. A U–238 nucleus originally at rest, decays by emitting an a-particle, say with a velocity of v m/s. The recoil velocity (in m/s) of the residual nucleus is?

  • -4v/234
  • v/234
  • v/4
  • 4v/238
Click for Answer/Explanation

-4v/234

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