An ideal heat engine can have an efficiency of 1 if the temperature of the low temperature reservoir is
A) 0 K.
B) 0°C.
C) 0°F.
D) 0°R.
E) the same as the temperature of the heat source.

Question

Quizplus · Accepted Answer

According to the Carnot efficiency formula, the efficiency (η) of a heat engine is given by η = 1 - (T_Low/T_High), where T_Low is the temperature of the low temperature reservoir and T_High is the temperature of the high temperature reservoir. As the denominator of this fraction cannot be zero or negative, the only way for the efficiency to be 1 is when T_Low is zero (in Kelvin). Therefore, the best choice is A).

An Ideal Heat Engine Can Have an Efficiency of 1