
${\mathrm{Q}_{2}=\mathrm{T}_{0}\left(2 \mathrm{S}_{0}-\mathrm{S}_{0}\right)=\mathrm{T}_{0} \mathrm{S}_{0} \text { and } \mathrm{Q}_{3}=0}$
${\eta=\frac{\mathrm{W}}{\mathrm{Q}_{1}}=\frac{\mathrm{Q}_{1}-\mathrm{Q}_{2}}{\mathrm{Q}_{1}}} $
${=1-\frac{\mathrm{Q}_{2}}{\mathrm{Q}_{1}}=1-\frac{\mathrm{T}_{0} \mathrm{S}_{0}}{\frac{3}{2} \mathrm{T}_{0} \mathrm{S}_{0}}=\frac{1}{3}}$


$A \rightarrow B :$ Isothermal expansion at temperature $T$ so that the volume is doubled from $V _{1}$ to $V _{2}=2 V _{1}$ and pressure changes from $P _{1}$ to $P _{2}$
$B \rightarrow C :$ Isobaric compression at pressure $P _{2}$ to initial volume $V _{1}$
$C \rightarrow A$ : Isochoric change leading to change of pressure from $P _{2}$ to $P _{1}$
Total workdone in the complete cycle $ABCA$ is
Choose the correct option out of the following for work done if processes $B C$ and $D A$ are adiabatic.