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Reversed Heat Engines

Physics: AQA A Level, topic 11.2.6

Reversed heat engines

Any engine that runs from cold to hot is a reversed heat engine.

Fridges

Fridges

  • A reverse heat engine does work to move heat energy from a hot body to a cold body.
  • It is the same as a normal heat engine but the heat energy transferred does not do work, it needs work.
Coefficient of performance

Coefficient of performance

  • The coefficient of performance of a reverse heat engine is like its efficiency.
  • COP=QcWCOP= \frac{{Q_c}}{W}
  • Where QcQ_c is the heat from the cold reservoir.

Test yourself on Reversed Heat Engines

  • Which of these is an example of a reversed heat engine?

  • Which is the correct equation for the coefficient of performance?

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