Question

A scientist says that the efficiency if his heat engine which operates at source temperature ${127}^{o}C$ and sink temperature ${27}^{o}C$ is $34$%, then:

• A. It is impossible
• B. It is possible but less probable
• C. It is quite probable
• D. Insufficient data

Answer 1

The correct option is A It is impossible

We know,

${\eta }_{max}=1-\frac{T_1}{T_2}=1-\frac{27+273}{127+273}=1-\frac{300}{400}=25\%$

Hence, 34$\%$ is impossible.