Q 11-11-081JEE MainJEE Main 2023 (31 Jan, Shift 2)Medium
Heat energy of $735\ \text{J}$ is given to a diatomic gas allowing the gas to expand at constant pressure. Each gas molecule rotates around an internal axis but does not oscillate. The increase in the internal energy of the gas will be
Answer: (A) $525\ \text{J}$
For a rigid diatomic gas $C_V=\tfrac52R$, $C_P=\tfrac72R$. At constant pressure
$$\Delta U=Q\frac{C_V}{C_P}=735\times\frac57=525\ \text{J}$$
Solution by Sreeraj P, M.Sc Physics