Question 22: A Carnot engine has an efficiency of 50% when its source is at a temperature 327^{\circ}\mathrm{C}. The temperature of the sink is :
(1) 100^{\circ}\mathrm{C}
(2) 200^{\circ}\mathrm{C}
(3) 27^{\circ}\mathrm{C}
(4) 15^{\circ}\mathrm{C}
Answer: Option (3)
Explanation:
The efficiency of a Carnot engine is given by
\eta = 1 - \frac{T_2}{T_1}where T_1 is the absolute temperature of the source and
T_2 is the absolute temperature of the sink.
The temperature of the source is
T_1 = 327 + 273 = 600 \, \mathrm{K}Given efficiency is
\eta = 50\% = 0.5Substituting the values,
0.5 = 1 - \frac{T_2}{600} \frac{T_2}{600} = 0.5 T_2 = 300 \, \mathrm{K}Converting the sink temperature into degree Celsius,
T_2 = 300 - 273 = 27^{\circ}\mathrm{C}Hence, the temperature of the sink is 27^{\circ}\mathrm{C}.
Therefore, the correct answer is Option (3).