Suppose that the system described by the T–S diagram in Fig. 12.25 is returned to its original state, state 1, by a reversible process depicted by a straight line from state 3 to state 1.
(a) The change in entropy of the system for this overall cyclic process is (1) positive, (2) zero, (3) negative. Explain.
(b) How much heat is transferred in the cyclic process?