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GATE 2020 ME (ME2) – Question 35

Thermal Engineering Applications · Refrigeration and heat pump cycles · 1 mark · Numerical answer

A reversed Carnot cycle operates between 27°C and −3°C. Find COP(refrigerator)/COP(heat pump), to two decimals.

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Correct answer: .89 to .91

Explanation

For a reversed Carnot cycle COPR=TL/(TH−TL),COPHP=TH/(TH−TL). Ratio=TL/TH=270/300=**0.90**, using kelvin. The common temperature difference cancels.