All Problems

Second law of thermodynamics, entropy

Problem 2.123

An ideal gas with the adiabatic exponent \(\gamma\) goes through a direct (clockwise) cycle consisting of adiabatic, isobaric, and isochoric lines. Find the efficiency of the cycle if in the adiabatic process the volume of the ideal gas (a) increases \(n\) -fold; (b) decreases \(n\) -fold.

Reveal Answer
 (a) η=1γn1nγ1 (b) η=1nγ1γ(n1)nγ1\text { (a) } \eta=1-\gamma \frac{n-1}{n^{\gamma}-1} \text { (b) } \eta=1-\frac{n^{\gamma}-1}{\gamma(n-1) n^{\gamma-1}}