Question

Identify the incorrect source for the corresponding variables of the first law.

(a) Absorbed radiation: dq

(b) Squeezing of volume: dw

(c) Heating: de

(d) Displacement of system boundary: dq

The question was posed to me in an online interview.

This is a very interesting question from A Brief Review of Thermodynamics topic in portion Compressible Flow – Preliminary Aspects of Aerodynamics

Answer 1

The correct option is (d) Displacement of system boundary: dq

To explain I would say: The change in dq or dw brings a change in de. Displacement of system boundary or squeezing of system volume are sources of dw. While heating and absorbing of radiation by mass in the system are sources of dq, therefore de.