Chapter-6: Work, Energy And Power

Chapter-6: Work, Energy And Power

1. The commercial unit of energy is-

  • Watt
  • Joule
  • Kilowatt-hour
  • None of these

[su_spoiler title=”answer” style=”fancy” icon=”caret”]Kilowatt-hour[/su_spoiler]

2. The product of force and displacement is called –

  • Energy
  • Momentum
  • Power
  • Work

[su_spoiler title=”answer” style=”fancy” icon=”caret”]Work [/su_spoiler]

3. Work will be said not to be done if the force and displacement are –

  • parallel
  • acting in the opposite direction
  • perpendicular
  • None of these

[su_spoiler title=”answer” style=”fancy” icon=”caret”]acting in the opposite direction [/su_spoiler]

4. Energy is-

  • the capacity for doing work
  • rate of doing work
  • change of work
  • None of these

[su_spoiler title=”answer” style=”fancy” icon=”caret”]the capacity for doing work[/su_spoiler]

5. Potential energy of an object of mass ‘m’ at a height ‘h’ is –

  • 1/2mv²
  • m²gh
  • mgh
  • mg

[su_spoiler title=”answer” style=”fancy” icon=”caret”]mgh [/su_spoiler]

6. The expression of kinetic energy is –

  • 1/2mv²
  • m²gh
  • mgh
  • mg

[su_spoiler title=”answer” style=”fancy” icon=”caret”]mgh [/su_spoiler]

7. Out of the following, which is not the unit of energy –

  • Joule
  • Calorie
  • Kilo-Watt
  • Electron-Volt

[su_spoiler title=”answer” style=”fancy” icon=”caret”]Kilo-Watt[/su_spoiler]

8. Joule is a unit of –

  • Work and Power
  • Power and Energy
  • Force
  • Work and Energy.

[su_spoiler title=”answer” style=”fancy” icon=”caret”]Work and Energy.[/su_spoiler]

9. Area under the Force-Displacement curve represents –

  • Velocity
  • Impulse
  • Acceleration
  • Work done

[su_spoiler title=”answer” style=”fancy” icon=”caret”]Work done [/su_spoiler]

10. The momentum of a body increased by 25%, then kinetic energy is increased by about –

  • 25 %
  • 56 %
  • 5 %
  • 38 %

[su_spoiler title=”answer” style=”fancy” icon=”caret”]56 % [/su_spoiler]

11. The rate of doing work is called –

  • energy
  • force
  • power
  • pressure

[su_spoiler title=”answer” style=”fancy” icon=”caret”]power[/su_spoiler]

12. What will be the kinetic energy of a substance when its velocity is doubled?

  • Double
  • Four times
  •  Half
  • One-fourth

[su_spoiler title=”answer” style=”fancy” icon=”caret”] Half [/su_spoiler]

13. What will be the kinetic energy of a body when its velocity is halved?

  • Double
  • Four times
  • Half
  • One-fourth

[su_spoiler title=”answer” style=”fancy” icon=”caret”]One-fourth[/su_spoiler]

14. Watt is the unit of the following –

  • Work
  • Power
  • Energy
  • None of these

[su_spoiler title=”answer” style=”fancy” icon=”caret”]Power [/su_spoiler]

15. If the velocity of a body becomes double then its kinetic energy becomes –

  • Double
  • Four times
  • Half
  • One-fourth

[su_spoiler title=”answer” style=”fancy” icon=”caret”]Four times [/su_spoiler]