The efficiency of an ideal heat engine working between the freezing point and boiling point of water, is :

26.8 % 20 % 12.5 % 6.25 %

26.8 %

Efficiency of heat engine : \(\eta = (1 - \frac{T_2}{T_1})\) T2 : Sink Temperature = 273 K ; T1 : Source Temperature = 373 K ; \(\eta\) % = 26.8 %