In one complete cycle a gas takes in 500 J of heat from a hot source and 300 J from a second source, and rejects 200 J to a cold sink. The net work done by the gas over the cycle is:

The Carnot cycle alternates two isothermal steps (heat absorbed at T_H, released at T_C) with two adiabatic steps (no heat exchange); the enclosed loop area equals the net work output, and η = 1−T_C/T_H is the maximum possible efficiency between those two temperatures.