Q 11-11-168JEE MainJEE Main 2025 (2 Apr, Shift 1)Easy
In an adiabatic process, which of the following statements is true?
Answer: (C) The molar heat capacity is zero
In an adiabatic process no heat is exchanged: $dQ = 0$, while the temperature does change. So the molar heat capacity $C = \dfrac{dQ}{n\,dT} = 0$.
Checking the others: from the first law $dU = -dW$, so work done by the gas equals the **decrease** in internal energy, not the increase; and the internal energy of an ideal gas $U = \frac f2 nRT$ increases with temperature. The heat capacity is infinite for an isothermal process, not an adiabatic one.
Only statement (3) is true.
Solution by Sreeraj P, M.Sc Physics