The ratio of specific heats of a gas is $\gamma$. The change in internal energy of one mole of the gas, when the volume changes from V to 2V at constant pressure P is :

Question

$$\begin {array} {1 1} (a)\;\frac{\gamma-1}{PV} & \quad (b)\;PV \\ (c)\;\frac{PV}{\gamma-1} & \quad (d)\;\frac{PV}{\gamma} \end {array}$$