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3 Conservation of energy

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Question 84
F

An electric heater receives 2000 J and transfers 1900 J to the thermal store of a room. A lamp receives 2000 J and transfers 1900 J to the thermal store of the same room.

The heater is used only for heating the room. The lamp is used only for lighting the room. Each device transfers all its remaining energy as light.

Which gives their efficiencies for these purposes?

[1]
A

heater 95%95\%95%; lamp 95%95\%95%

B

heater 5%5\%5%; lamp 95%95\%95%

C

heater 95%95\%95%; lamp 5%5\%5%

D

heater 5%5\%5%; lamp 5%5\%5%

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3 Conservation of energy Questions

  1. GCSE
  2. /Physics
  3. /3 Conservation of energy

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