no, of moles of gas, \(\mu =2\)
For diatomic gas \(\gamma = 1.4\)
Work done during an adiabatic change
\(W = \frac{{\mu R\left( {{T_1} - {T_2}} \right)}}{{\gamma - 1}}\)
\( \Rightarrow 830 = \frac{{2 \times 8.3\left( {\Delta T} \right)}}{{1.4 - 1}} = \frac{{2 \times 8.3\left( {\Delta T} \right)}}{{0.4}}\)
\( \Rightarrow \Delta T = \frac{{830 \times 0.4}}{{2 \times 8.3}} = 20\,K\)