Question

A refrigerator of coefficient of performance 5 that extracts heat from the cooling compartment at the rate of 250 J per cycle is placed in a room. The heat released per cycle to the room by the refrigerator is

• A. 250 J
• B. 50 J
• C. 200 J
• D. 300 J

Hint:

COP (refrigerator) $= \frac{Q_c}{W}$. $Q_h = Q_c + W$.

Answer 1

The Correct Option is D

Coefficient of performance (COP) of a refrigerator is given by $\text{COP} = \frac{Q_c}{W}$, where $Q_c$ is the heat extracted from the cold reservoir (cooling compartment) and $W$ is the work done. We are given COP = 5 and $Q_c = 250$ J. $5 = \frac{250}{W}$ $W = \frac{250}{5} = 50$ J. The heat released to the room $Q_h = Q_c + W = 250 + 50 = 300$ J.