Explanation

(a) For adiabatic change, $\frac{T^{\gamma}}{P^{\gamma - 1}} = constant$
$\left( \frac{T_{1}}{T_{2}} \right)^{\gamma} = \left( \frac{p_{1}}{p_{2}} \right)^{\gamma - 1\ }$
${\ \ \ \ \left( \frac{27 + 273}{627 + 273} \right)}^{1.5} = \left( \frac{1}{p_{2}} \right)^{0.5}$
or $\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \left( \frac{1}{3} \right)^{3/2} = \left( \frac{1}{P_{2}} \right)^{1/2}$
$\Rightarrow \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ P_{2} = 27\ atm$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ = \ 27 \times 1.07 \times 10^{5}$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ = 27 \times 10^{5}\ Nm^{- 2}$