Question

The equation of the second law of thermodynamics says that____

(a) Total change in entropy is always zero

(b) We cannot find entropy for an irreversible process

(c) Entropy change is defined as the heat added in an irreversible process

(d) Entropy is a state process

This question was addressed to me in quiz.

This intriguing question comes from A Brief Review of Thermodynamics topic in chapter Compressible Flow – Preliminary Aspects of Aerodynamics

Answer 1

Right option is (d) Entropy is a state process

To explain: According to the second law, entropy is a state process. We can find the entropy change by the heat added in a reversible process. Using the total head added, we can find the heat added in the irreversible process also (since entropy is a state process).