Consider a refrigerator and a heat pump working on the reserved Carnot cycle between the same temperature limits. Which of the following is correct?
(a) COP of refrigerator = COP of heat pump
(b) COP of refrigerator = COP of heat pump + 1
(c) COP of refrigerator = COP of heat pump – 1
(d) COP of refrigerator = inverse of the COP of heat pump