Write the degree of freedom for a diatomic rigid rotator.

If $\gamma$ is the ratio of specific heats of an ideal gas,the number of degrees of freedom of the gas molecules is .......

For polyatomic gases,the ratio of molar specific heat at constant pressure to constant volume is $(f=$ degrees of freedom $)$

For two different gases $X$ and $Y,$ having degrees of freedom $f_1$ and $f_2$ and molar heat capacities at constant volume $C_{v_1}$ and $C_{v_2}$ respectively, for an adiabatic process, the $\ln P$ versus $\ln V$ graph is plotted as shown:

The degrees of freedom of a triatomic gas is

Define degree of freedom.