An ideal gas goes from state $A$ to state $B$ via three different processes as indicated in the $p-V$…
An ideal gas goes from state $A$ to state $B$ via three different processes as indicated in the $p-V$ diagram
If $Q_1, Q_2, Q_3$ indicate the heat absorbed by the gas along the three processes and $\Delta U_1, \Delta U_2, \Delta U_3$ indicate the change in internal energy along the three processes respectively, then
$Q_1 > Q_2 > Q_3$ and $\Delta U_1=\Delta U_2=\Delta U_3$
$Q_3 > Q_2 > Q_1$ and $\Delta U_1=\Delta U_2=\Delta U_3$
$Q_1=Q_2=Q_3$ and $\Delta U_1 > \Delta U_2 > \Delta U_3$
For all process 1,2 and 3
$\begin{array}{ll}
& \Delta U=U_B-U_A \text { is same } \\
\therefore & \Delta U_1=\Delta U_2=\Delta U_3 \\
\text {Now, } & \Delta Q=\Delta U+\Delta W
\end{array}$
Now, $\Delta W=$ work done by the gas
$\therefore \quad \Delta Q_1 > \Delta Q_2 > \Delta Q_3$
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