The slope of isothermal and adiabatic curves are related as

For isothermal process $p V=$ constant $\Rightarrow \quad$\left(\frac{d p}{d V}\right)=-\frac{p}{V}=$slope of isothermal curve For adiabatic process,$\mathrm{pV}^\gamma=$constant$\Rightarrow \quad\left(\frac{d p}{d V}\right)=-\frac{\gamma p}{V}=$slope of adiabatic curve Clearly,$\quad\left(\frac{d p}{d V}\right)_{\text{adiabatic }}=\gamma\left(\frac{d p}{d V}\right)_{\text{isothermal }}