At constant volume,the specific heat of a gas is $\frac{3R}{2}$. Then the value of $\gamma$ will be ....

The specific heat of a gas:

If the ratio of specific heat of a gas at constant pressure to that at constant volume is $\gamma$,the change in internal energy of a mass of gas,when the volume changes from $V$ to $2V$ at constant pressure $p$,is

Which of the following formulae is wrong?

The difference between the two specific heats of $1\, g$ of helium gas at $NTP$ is .... $cal\, g^{-1} K^{-1}$. (Atomic weight of helium $= 4$ and $J = 4.186 \times 10^7\, erg\, cal^{-1}$)

Molar specific heat at constant pressure $C_p$ is related to internal energy $U$ and absolute temperature $T$ as $C_p$ is equal to