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MCQ practice · SSC Physics Board questions · Chapter 4: Work, Power and Energy

Barishal Board 2021

The unit of energy-

  1. i. joule
  2. ii. newton-metre
  3. iii. watt

Think it through first, then pick an option.

  1. a i and ii
  2. b i and iii
  3. c ii and iii
  4. d i, ii and iii
Answer and explanation

Correct answer: a i and ii

i true: The unit of energy is the joule. ii true: 1 J = 1 N m, so the newton-metre is also a unit of energy. iii false: The watt is the unit of power (J/s), not of energy.

Why the other options are wrong

  • b i and iii: This is not the answer; the right combination is i and ii. i true: The unit of energy is the joule. ii true: 1 J = 1 N m, so the newton-metre is also a unit of energy. iii false: The watt is the unit of power (J/s), not of energy.
  • c ii and iii: This is not the answer; the right combination is i and ii. i true: The unit of energy is the joule. ii true: 1 J = 1 N m, so the newton-metre is also a unit of energy. iii false: The watt is the unit of power (J/s), not of energy.
  • d i, ii and iii: This is not the answer; the right combination is i and ii. i true: The unit of energy is the joule. ii true: 1 J = 1 N m, so the newton-metre is also a unit of energy. iii false: The watt is the unit of power (J/s), not of energy.