Question
A scientist says that the efficiency of his heat engine which operates at source temperature $127°C$ and sink temperature $27°C$ is $26\%$, then
✓
Answer
(a) ${\eta _{\max }} = 1 - \frac{{{T_2}}}{{{T_1}}} = 1 - \frac{{300}}{{400}} = \frac{1}{4} = 25\% $
So $26\%$ efficiency is impossible
So $26\%$ efficiency is impossible
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