P-V diagram of a diatomic gas is a straight line passing through origin. The molar heat capacity of the gas in the process will be

Options

A. `4 R`
B. `3 R`
C. `(4R)/3`
D. `2.5 R`

Answer

B

Explanation

As p- V diagram is a straight line passing through origin , therfore, `ppropV" or "pV^(_1)` = constant .
In the process , `pV^(x)` = constant, molar heat capacity is
given by , `C=(R)/(gamma-1)+(R)/(1-x)`
Where , `x=-1` here and `gamma=1.4` for diatomic gas
`C=(R)/(1.4-1)+(R)/(1-(-1))`
`=(5)/(2)R+(R)/(2)=3R`