Question

The temperature of the source of a Carnot heat engine is $0^{o}C$ and that of a sink is $-{39}^{o}C$. The efficiency of the heat engine is

• A. $39\%$
• B. $14.3\%$
• C. $0$
• D. none of these

Answer 1

Answer: (B)

$14.3\%$

The efficiency of the cycle is given as $\eta =1-\frac{T_2}{T_1}$. Here $T_1$ is the temperature of the source and $T_2$ is the temperature of the sink. Thus we get $\eta =1-\frac{234}{273}=1-0.857=0.142=14.2\%$