試題詳解

9. Which of the following statement is correct?
(A) The law of thermodynamics states that two systems in thermal contact always reach thermal equilibrium in the end.
(B) The entropy of any macroscopic system never decreases over time.
(C) The entropy of an idcal gas is doubled if its volume is doubled at the same temperature.
(D) Any irreversible engine always has a smaller efficiency than any reversible engine.
(E) By choosing a suitable definition of Kelvin, the Boltzmann constant has an exact value that does not have to be determined by experiments.