What is the significance of the heat capacity ratio $\gamma = \frac{C_{P}}{C_{V}}$ for a gas?

The specific heat at constant pressure $(C_P)$ is greater than the specific heat at constant volume $(C_V)$ for the same gas because:

For a rigid diatomic molecule,the universal gas constant $R = n C_P$,where $C_P$ is the molar specific heat at constant pressure and $n$ is a number. Hence,$n$ is equal to

$70 \, cal$ of heat are required to raise the temperature of $2 \, moles$ of an ideal gas at constant pressure from $30^{\circ}C$ to $35^{\circ}C$. The amount of heat required to raise the temperature of the same gas through the same range ($30^{\circ}C$ to $35^{\circ}C$) at constant volume is ..... $cal$ $(R = 2 \, cal/mol \cdot K)$.

For a gas,$\frac{R}{C_{V}} = 0.4$,where $R$ is the universal gas constant and $C_{V}$ is the molar specific heat at constant volume. The gas is made up of molecules which are

The correct relation between $\gamma = \frac{C_p}{C_v}$ and temperature $T$ is: