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

Answer

b

Explanation

As p-V diagram is a straight line passing through origin, therefore, p=V or `pV^(-1)` =constnat
in the process `pV^(x)=`constant , molar heat capacity is given by `C=(R)/(gamma-1)+(R)/(1-x)`
where, x=-1 and `gamma=`1.4 for diatomic gas
`C=(R)/(14-1)+(R)/(1-(-1))=(5)/(2)R+(R)/(2)`
`C=2R`