for a diatomic ideal gas in a closed system , which of the following plots does not correctly describe the relation between various thermodynamic quantities ?

Options

A.
B.
C.
D.

Answer

C

Explanation

`C_(v) = f/2 R`
`C_(p) =(f/2+1)R` where f= degree of freedom at normal temperature
At normal temperature f=5 for diatomic gas.
At higher temperature vibrational degree of freedom also becomes active, so the value of f in both `C_(v)` and `C_(p)` will shot up after a particular temperature. Hence graph (C) is incorrect.