Question

The efficiency of Carnot's engine operating between reservoirs, maintained at temperatures $27^{o}C$ and $- 123^{o}C,$ is

• A. 50%
• B. 24%
• C. 0.75%
• D. 0.4%

Answer 1

Answer: (A)

50%

Answer 2

$\eta = 1 - \frac{T_{2}}{T_{1}} = 1 - \frac{(273 + 123)}{(273 + 27)} = 1 - \frac{150}{300} = \frac{1}{2} = 50\%$