Kinetic & Potential Energy — Homi Bhabha Exam Physics MCQs with Solutions
Free Homi Bhabha Exam Physics Kinetic & Potential Energy MCQs with step-by-step solutions (8 questions). Part of Work, Energy & Power. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Kinetic & Potential Energy · medium · numerical
The kinetic energy of a 2 kg body moving at 10 m/s is:
A. 20 J
B. 10 J
C. 100 J ✓ Correct
D. 200 J
Solution: K.E. $= \tfrac12 m v^2 = \tfrac12 (2)(10^2) = 100$ J.
Q2 — Kinetic & Potential Energy · hard · numerical
If the speed of a moving body is doubled, its kinetic energy becomes:
A. 8 times
B. unchanged
C. 4 times ✓ Correct
D. 2 times
Solution: K.E. $\propto v^2$, so doubling the speed multiplies the kinetic energy by $2^2 = 4$.
Q3 — Kinetic & Potential Energy · medium · numerical
The potential energy of a 5 kg body raised to a height of 4 m (taking $g = 10$ m/s²) is:
A. 100 J
B. 20 J
C. 9 J
D. 200 J ✓ Correct
Solution: P.E. $= mgh = 5 \times 10 \times 4 = 200$ J.
Q4 — Kinetic & Potential Energy · hard · numerical
Two bodies of masses 2 kg and 4 kg move with the same kinetic energy. The ratio of their speeds (2 kg : 4 kg) is:
A. $1 : \sqrt{2}$
B. 1 : 2
C. 2 : 1
D. $\sqrt{2} : 1$ ✓ Correct
Solution: Equal K.E.: $\tfrac12 m_1 v_1^2 = \tfrac12 m_2 v_2^2 \Rightarrow \dfrac{v_1}{v_2} = \sqrt{\dfrac{m_2}{m_1}} = \sqrt{2}$.
Q5 — Kinetic & Potential Energy · medium · theory
A stretched bow (about to shoot an arrow) possesses:
A. potential energy ✓ Correct
B. sound energy
C. no energy
D. only kinetic energy
Solution: A stretched bow stores elastic potential energy, which converts to the arrow's kinetic energy on release.
Q6 — Kinetic & Potential Energy · hard · numerical
A body of mass 1 kg is dropped from a height of 5 m. Just before hitting the ground (taking $g = 10$ m/s²) its kinetic energy is:
A. 10 J
B. 25 J
C. 5 J
D. 50 J ✓ Correct
Solution: By energy conservation, K.E. at bottom = initial P.E. $= mgh = 1 \times 10 \times 5 = 50$ J.
Q7 — Kinetic & Potential Energy · medium · numerical
If the mass of a moving body is doubled without changing its speed, its kinetic energy becomes:
A. 4 times
B. half
C. unchanged
D. 2 times ✓ Correct
Solution: K.E. $= \tfrac12 m v^2 \propto m$; doubling the mass doubles the kinetic energy.
Q8 — Kinetic & Potential Energy · hard · theory
The work done by the net force acting on a body is equal to the change in its:
A. power
B. momentum
C. potential energy
D. kinetic energy ✓ Correct
Solution: By the work–energy theorem, net work done = change in kinetic energy.