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

**2. Two bodies of masses m _{1} and m_{2} are moving with the same kinetic energy. If P_{1} and P_{2} are their respective momentum, the ratio P_{1} P_{2} is equal to –**

- m
_{1}/m_{2} - sqrt(m
_{1}/m_{2}) - sqrt(m
_{2}/m_{1}) - m
_{2}/m_{1}

**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

**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 θ _{1} and then angle θ_{2} with the vertical. When released from these positions, speeds with which it passes the lowest positions are v_{1} & v_{2 }respectively. Then, v_{1}/v_{2} is-**

- 1-cos θ
_{1}/1-cos θ_{2} - sqrt(1-cos θ
_{1}/1-cos θ_{2}) - sqrt(2gx(1-cos θ
_{1})/1-cos θ_{2}) - sqrt((1-cos θ1)/2gx(1-cos θ
_{2}))

**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