The Thermal Efficiency of a Reversible Heat Engine Operating Between

Multiple Choice

The thermal efficiency of a reversible heat engine operating between two given thermal reservoirs is 0.4. The device is used either as a refrigerator or as a heat pump between the same reservoirs. Then the coefficient of performance as a refrigerator (COP) R and the co-efficient of performance as a heat pump (COP) HP are

A) (COP) R = (COP) HP = 0.6
B) (COP) R = 2.5; (COP) HP = 1.5
C) (COP) R = 1.5; (COP) HP = 2.5
D) (COP) R = (COP) HP = 2.5