1. The problem statement, all variables and given/known data Compute the efficiency of the following cycle: 2. Relevant equations 3. The attempt at a solution I know there's an isothermic process between a and b, where heat comes into the system, let's call it Qh. I also know that between b and c heat will leave the system, let's call it Qc. The process from c to a is adiabatic. The efficiency, n, is equal to: η = 1- Qc / Qh = 1 - Qc / T2(S2-S1) The problem is that I don't know how to compute Qc... Any help would be highly appreciated. Also, if anyone has a good book on the subject I'd appreciate. Thanks.