Question

The temperature of source and sink of a heat engine are $127^{\circ }C$ and $27^{\circ }C$ respectively. An inventor claims its efficiency to be $26\%$, then:

• A. it is impossible
• B. it is possible with high probability
• C. it is possible with low probability
• D. data are insufficient.

Answer 1

Answer: (A)

$\eta =1-\frac{300}{400}=\frac{100}{400}=\frac{1}{4}$
$\eta =\frac{1}{4}\times 100=25\%$
Hence, it is not possible to have efficiency more than $25\%$.