Question

10 J of heat and 5 J of work is supplied to a system and 20 J of heat is taken out, then the system is which of the following?

(a) Steady state

(b) Unsteady state

(c) Closed

(d) None of the mentioned

I got this question in a national level competition.

Asked question is from Energy Balances for Closed, Steady-State Systems in chapter Introduction to Energy Balances for Processes without Reaction and Calculation of Enthalpy Changes of Basic Chemical Engineering

Answer 1

The correct answer is (b) Unsteady state

The best explanation: ∆E = 10 + 5 – 20 = – 5 J which is not equal to zero, so the system is unsteady state system.