Ans: (A)
\(P \propto T^{3}\)
or, \(\mathrm{P}=\mathrm{KT}^{3}\) or \(\mathrm{PT}^{-3}=\mathrm{K} \ldots \ldots\) (i)
For reversible adiabatic process
\(T^{\gamma} P^{1-\gamma}=K\)
\(\mathrm{PT}^{\frac{\gamma}{1-\gamma}}=\mathrm{K} \cdots \cdots\) (ii)
Comparing equation (i) and equation (ii)
\(\frac{\gamma}{1-\gamma}=-3\)
or \(\gamma=-3+3 \gamma\)
or \(\gamma=\frac{3}{2}\)