A thermodynamic system is taken through the cycle $PQRSP$ process. The net work done by the system is ……. $J$

A system goes from $A$ to $B$ via two processes $I$ and $II$ as shown in figure. If $\Delta {U_1}$ and $\Delta {U_2}$ are the changes in internal energies in the processes $I$ and $II$ respectively, then

One mole of a gas obeying the equation of state $P(V-b)=R T$ is made to expand from a state with coordinates $\left(P_{1}, V_{1}\right)$ to a state with $\left(P_{2}, V_{2}\right)$ along a process that is depicted by a straight line on a $P-V$ diagram. Then, the work done is given by

An ideal gas is taken from point $A$ to the point $B,$ as shown in the $P-V$ diagram, keeping the temperature constant. The work done in the process is

One mole of an ideal gas goes from an initial state $A$ to final state $B$ via two processes : It first undergoes isothermal expansion from volume $V$ to $3\, V$ and then its volume is reduced from $3\, V$ to $V$ at constant pressure. The correct $P-V$ diagram representing the two processes is