Question

For a reversible process, which is not the correct statement?

(a) No presence of viscosity

(b) dw = -pdv

(c) dq – pdv = de

(d) Mass diffusion occurs

I had been asked this question in quiz.

The query is from A Brief Review of Thermodynamics in portion Compressible Flow – Preliminary Aspects of Aerodynamics

Answer 1

Right choice is (d) Mass diffusion occurs

For explanation: Reversible process has no dissipative effects i.e. viscosity and mass diffusion are absent. Also, work in a reversible process is given as dw = -pdv. Therefore, the first equation of thermodynamics can be written as dq – pdv = de.