Work, Energy and Power MCQs with Solutions
Work, Energy and Power MCQs with Solutions
Class: CBSE Class 11
Subject: Physics
Section: Work, Energy and Power
Topic: Work, Energy and Power MCQs with Solutions
Board: CBSE Board Examination (NCERT Syllabus Based)
Subject: Physics
Section: Work, Energy and Power
Topic: Work, Energy and Power MCQs with Solutions
Board: CBSE Board Examination (NCERT Syllabus Based)
Q1. Work done is maximum when angle between force and displacement is:
Answer: A) 0°
Explanation: W = F s cosθ. cos0° = 1 → Maximum work.
Explanation: W = F s cosθ. cos0° = 1 → Maximum work.
Q2. SI unit of work:
Answer: Joule
Explanation: 1 J = 1 N·m.
Explanation: 1 J = 1 N·m.
Q3. Work done in circular motion by centripetal force:
Answer: Zero
Explanation: Force ⟂ displacement → cos90° = 0.
Explanation: Force ⟂ displacement → cos90° = 0.
Q4. Kinetic energy depends on:
Answer: C
Explanation: KE = ½ mv².
Explanation: KE = ½ mv².
Q5. Potential energy of body at height h:
Answer: A
Explanation: Gravitational PE = mgh.
Explanation: Gravitational PE = mgh.
Q6. Work–Energy theorem states:
Answer: B
Explanation: Net work equals change in kinetic energy.
Explanation: Net work equals change in kinetic energy.
Q7. Energy unit:
Answer: Joule
Q8. Power is rate of doing:
Answer: Work
Explanation: P = W/t.
Explanation: P = W/t.
Q9. SI unit of power:
Answer: Watt
Q10. Commercial unit of energy:
Answer: kWh
Q11. When velocity doubles, KE becomes:
Answer: Four times (∝ v²).
Q12. Work done by gravity lifting body:
Answer: Negative.
Q13. Spring energy stored:
Answer: Elastic potential energy.
Q14. Formula of elastic PE:
Answer: ½ kx².
Q15. Conservative force example:
Answer: Gravitational force.
Q16. Non-conservative force:
Answer: Friction.
Q17. Energy conservation states:
Answer: Energy neither created nor destroyed.
Q18. At highest point KE:
Answer: Minimum.
Q19. Mechanical energy =
Answer: KE + PE.
Q20. Efficiency formula:
Answer: Output/Input × 100%.
Q21. Power of fast worker:
Answer: Greater.
Q22. Work zero when displacement:
Answer: Zero.
Q23. Unit of k (spring constant):
Answer: N/m.
Q24. 1 HP equals:
Answer: 746 W.
Q25. Energy stored due to position:
Answer: Potential energy.
Q26. Work done downhill by gravity:
Answer: Positive.
Q27. KE at rest:
Answer: Zero.
Q28. Work dimension:
Answer: ML²T⁻².
Q29. Energy transfer rate:
Answer: Power.
Q30. Total mechanical energy in free fall:
Answer: Constant (ignoring air resistance).
