Pick out the wrong statement.

A. The net change in entropy in any reversible cycle is always zero

B. The entropy of the system as a whole in an irreversible process increases

C. The entropy of the universe tends to a maximum

D. The entropy of a substance does not remain constant during a reversible adiabatie change

Answer: Option D

Solution(By Examveda Team)

We know for reversible process $$TdS = \delta Q$$   and since in adiabatic process $$\delta Q = 0 \Rightarrow TdS = 0$$
So reversible adiabatic process is an isentropic process.