Question

The efficiency of a heat engine working between the freezing point and boiling point of water is ………

(a) 6.25% 

(b) 20% 

(c) 26.8% 

(d) 12.5%

Answer 1

Correct answer is (c) 26.8%

Freezing point of water T_L = 0°C = 273K 

Boiling point of water T_H – 100°C = 373K

∴ Efficiency, η = 1 - \(\frac{T_L}{T_H} = 1 - \frac{273}{373}\) = 0.2861; n = 26.8%