Chapter 7: Entropy

In the preceding chapter we obtained a number of important results by applying the second law to cyclic processes associated with heat engines and reversed heat engines, operating with one and two thermal reservoirs. The concept of a reversible process, though an idealization of real processes, provided a means to find the upper limit of the efficiency of heat engines operating with two heat reservoirs. The maximum efficiency, called the Carnot-cycle efficiency, is a unique function of the two reservoir temperatures. This lead to the development of the thermodynamic temperature scale. Finally, we generalized these results for cyclic systems experiencing heat interactions with any number of thermal reservoirs.