P-V plots for two gases during adiabatic processes are shown in Fig. 15.9.6. Plot 1 and 2 should correspond respectively to

Options

A. `He` and `O_2`
B. `O_2` and `He`
C. `He` and `Ar`
D. `O_2` and `N_2`

Answer

B

Explanation

For adiabatic process, `PV^(gamma)=`constant
For monatomic gas, `gamma=(C_(p))/(C_(v))=1.67`
For diatomic gas, `gamma=1.4`
Since `gamma_("diatomic") lt gamma_("monatomic")` , so with increase in volumem, decrease in pressure will be more for monatomic gas.
`implies` Graph `1` is for diatomic and Graph `2` is for monatomidc.
Correct option is (b) .