Figure shows the variation in temperature $(\Delta \mathrm{T})$ with the amount of heat supplied…
Figure shows the variation in temperature $(\Delta \mathrm{T})$ with the amount of heat supplied $\mathrm{(Q)}$ in an isobaric process corresponding to a monoatomic $\mathrm{(M)}$, diatomic $\mathrm{(D)}$ and a polyatomic $\mathrm{(P)}$ gas. The initial state of all the gases are the same and the scales for the two axes coincide. Ignoring vibrational degrees of freedom, the lines $a, b$ and $c$ respectively correspond to :
$\mathrm{P}$, $\mathrm{M}$ and $\mathrm{D}$
$\mathrm{M}$, $\mathrm{D}$ and $\mathrm{P}$
$\mathrm{P}$, $\mathrm{D}$ and $\mathrm{M}$
$\mathrm{D}$, $\mathrm{M}$ and $\mathrm{P}$
Solution
On giving same amount of heat at constant pressure, there is no change in temperature for mono, dia and polyatomic.
$(\Delta \mathrm{Q})_{\mathrm{P}}=\mu \mathrm{C}_{\mathrm{p}} \Delta \mathrm{T}\left(\mu=\frac{\text { No. of molecules }}{\text { Avogedro's no. }}\right)$
or $\quad \Delta \mathrm{T} \propto \frac{1}{\text { no. of molecules }}$
