2. Thermodynamics

Second Law — Quiz

Test your understanding of second law with 5 practice questions.

Practice Questions

Question 1

Which formula best represents the statistical definition of entropy in terms of the number of microstates $\Omega$ and Boltzmann’s constant $k$?

Question 2

What is the maximum coefficient of performance (COP) for an ideal refrigerator operating between a cold space at temperature $T_C = 275\,\mathrm{K}$ and a hot reservoir at temperature $T_H = 315\,\mathrm{K}$?

Question 3

For a reversible heat engine receiving $Q=800\,\mathrm{kJ}$ from a reservoir at $T_H=600\,\mathrm{K}$ with ambient temperature $T_0=300\,\mathrm{K}$, what is the maximum theoretical work output $W_{\mathrm{max}}$?

Question 4

A process generates entropy $S_{\mathrm{gen}}=0.3\,\mathrm{kJ/K}$ in an environment at $T_0=298\,\mathrm{K}$. What is the exergy destruction (irreversibility) in $\mathrm{kJ}$?

Question 5

A compressor requires an ideal isentropic work of 50 kJ/kg but actually consumes 65 kJ/kg. What is its isentropic efficiency $\eta_{\mathrm{isen}}$?