Question

p-V plot of two gases during adiabatic process are shown in figure. Plots 1 and 2 should correspond respectively to:

• A. $He$ and $O_2$
• B. $O_2$ and $He$
• C. $He$ and $Ar$
• D. $O_2$ and $N_2$

Answer 1

Answer: (B)

$O_2$ and $He$

The slope of the adiabatic process of P-V diagram

$\left(\frac{dP}{dV}\right)=\gamma \frac{P}{V}$

From the graph,

$(slope{)}_2>(slope{)}_1$ at points where the plots intersect an imaginary line passing through the origin

${\gamma }_2>{\gamma }_1$
Also, we know ${\gamma }_{monoatomic}>{\gamma }_{diatomic}$

Therefore the first plot corresponds to $O_2$ and the second plot corresponds to $He$

The correct option is B.