UNIT IV: Work, Energy and Power - Online Test

Q1. A uniform force of (2iˆ+ ˆj) N acts on a particle of mass 1 kg. The particle displaces from position (3 ˆj + ˆk ) m to (5iˆ+ 3ˆj) m. The work done by the force on the particle is
Answer : Option C
Explaination / Solution:
No Explaination.

Q2. A ball of mass 1 kg and another of mass 2 kg are dropped from a tall building whose height is 80 m. After, a fall of 40 m each towards Earth, their respective kinetic energies will be in the ratio of
Answer : Option D
Explaination / Solution:
No Explaination.

Q3. A body of mass 1 kg is thrown upwards with a velocity 20 m s−1. It momentarily comes to rest after attaining a height of 18 m. How much energy is lost due to air friction?. (Take g= 10ms-2
Answer : Option A
Explaination / Solution:
No Explaination.

Q4. An engine pumps water continuously through a hose. Water leaves the hose with a velocity v and m is the mass per unit length of the water of the jet. What is the rate at which kinetic energy is imparted to water ?.
Answer : Option A
Explaination / Solution:
No Explaination.

Q5. A body of mass 4 m is lying in xy-plane at rest. It suddenly explodes into three pieces. Two pieces each of mass m move perpendicular to each other with equal speed v. The total kinetic energy generated due to explosion is
Answer : Option B
Explaination / Solution:
No Explaination.

Q6. The potential energy of a system increases, if work is done
Answer : Option A
Explaination / Solution:
No Explaination.

Q7. What is the minimum velocity with which a body of mass m must enter a vertical loop of radius R so that it can complete the loop?
Answer : Option C
Explaination / Solution:
No Explaination.

Q8. The work done by the conservative force for a closed path is
Answer : Option B
Explaination / Solution:
No Explaination.

Q9. If the linear momentum of the object is increased by 0.1%, then the kinetic energy is increased by
Answer : Option B
Explaination / Solution:
No Explaination.

Q10. If the potential energy of the particle is ­α - β/2 x2, then force experienced by the particle is
Answer : Option C
Explaination / Solution:
No Explaination.