Question

Internal energy change, when a system goes from state A and B is 40 kJ mole^-1. If the system goes from A and B by a reversible path and returns to state A by an irreversible path, what would be the net change in internal energy?

(a) 40 kJ

(b) Greater than 40 kJ

(c) Later than 40 kJ

(d) Zero

This question was addressed to me in an interview.

Question is taken from Thermal Equilibrium topic in portion Kinetic Theory of Gases of Engineering Physics I

Answer 1

Right answer is (d) Zero

To explain: As the system returns to the initial state A, the change in internal energy is zero.