Q8. A sample of gas at temperature $T$ is adiabatically expanded to double its volume. Adiabatic constant for the gas is $\gamma = 3 / 2$. The work done by the gas in the process is: ( $\mu = 1$ mole)\\
(1) $R T [ 1 - 2 \sqrt { 2 } ]$\\
(2) $R T [ \sqrt { 2 } - 2 ]$\\
(3) $R T [ 2 - \sqrt { 2 } ]$\\
(4) $R T [ 2 \sqrt { 2 } - 1 ]$