P-V plots for two gases during adiabatic processes are shown in the figure. Plots 1 and 2 should correspond respectively to

At a given pressure (Po) and Volume (Vo), Slope of adiabatic process is equal to −γP0V0.From the diagram, γP0V01<γP0V02⇒γ1<γ2⇒1+2f1<1+2f2⇒f1>f2  For O2,f=5 and for He f=3