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. `4R`
B. `2.5R`
C. `3R`
D. `4R/3`

Answer

C

Explanation

`P-V` diagram of the gas is a straight line passing through origin.
Hence `p prop V`
Molar heat capacity in the process `PV^(x)`= constant is given by
`C = R/(gamma-1) + R/(1-x)`
Here, `gamma = 1.4` (for diatomic gas)
`C = R/(1.4-1) + R/(1+1) = 3R` .