Question

17) If the efficiency of a Carnot engine were to be 100%, the heat sink would have to be

A) at absolute zero.
B) at 0°C.
C) at 100°C.
D) infinitely hot.

Answer 1

A) at absolute zero.

Step-by-step explanation:

The efficiency of a Carnot engine is given by the formula:
η = 1 - T2/T1 where T2 is the temperature of the heat sink and T1 the temperature of the source reservoir

Both temperatures are in Kelvin

where T is the temperature of the heat sink and

Therefore for 100% efficiency, η would have to be 1 which means that the heat sink temperature which is at the numerator will have to be 0°K which is absolute zero