A reversible engine takes in 40. Joules of heat, does 10. J of work, and expels 30. J of wasted heat during each cycle. If it is operated in reverse as a refrigerator, then its COP would be

Question

Quizplus · Accepted Answer

The Coefficient of Performance (COP) for a refrigerator is defined as the ratio of the heat removed from the refrigerated space (Q_c) to the work input (W). Here, when operated in reverse, the engine would remove 30 J of heat (the heat it previously expelled) and require 10 J of work (the work it previously did). Thus, COP = Q_c / W = 30 J / 10 J = 3.

A Reversible Engine Takes in 40