Question

The efficiency of a Carnot engine operating between steam point and ice point is:

• A. 100%
• B. 50%
• C. 77%
• D. 27%
• E. 11%

Hint:

Carnot's theorem provides a maximum efficiency that no engine operating between two temperatures can exceed.

Answer 1

The Correct Option is D

The efficiency (\( \eta \)) of a Carnot engine is given by: \[ \eta = 1 - \frac{T_{{cold}}}{T_{{hot}}} \] where \( T_{{cold}} = 273 \, {K} \) (ice point) and \( T_{{hot}} = 373 \, {K} \) (steam point). Calculating: \[ \eta = 1 - \frac{273}{373} \approx 0.268 = 26.8\% \] This rounds to approximately 27%.