Question

A reversible engine takes heat from a reservoir at ${527}^{o}C$ and gives out to the sink at ${127}^{o}C$. The engine is required to perform useful mechanical work at the rate of 750 watt. The efficiency of the engine is

• A. 10%
• B. 30%
• C. 50%
• D. 70%

Answer 1

Answer: (C)

50%

Efficiency of the engine is
$\eta =1-\frac{T_c}{T_h}$
$\eta =1-\frac{400}{800}=1-0.5=0.5$
The efficiency of the engine is 50%
Option C.