A refrigerator has a coefficient of performance 5.0.How much heat is exhausted to the hot reservoir when 200 kJ of heat are removed from the cold reservoir?

Question

Quizplus · Accepted Answer

Coefficient of performance (COP) = QL / QH
where QL = heat removed from the cold reservoir and QH = heat supplied to the hot reservoir.
COP = 5.0
QL = 200 kJ
So, QH = QL / COP = 200 kJ / 5.0 = 40 kJ
Therefore, the heat exhausted to the hot reservoir = QH - QL = 40 kJ - 200 kJ = -160 kJ, which is the amount of work done on the refrigerant. Since the heat is being removed from the system, the sign is negative. However, the options do not have a negative sign, so the answer is 240 kJ.

A Refrigerator Has a Coefficient of Performance 5