Which of the curves in the given $P-V$ diagram represents an adiabatic process and an isothermal process,respectively?

The $P-V$ diagram of $2\,g$ of helium gas for a certain process $A \to B$ is shown in the figure. What is the heat given to the gas during the process $A \to B$ (in $,P_0V_0$)?

Three different processes that can occur in an ideal monoatomic gas are shown in the $P$ vs $V$ diagram. The paths are labelled as $A \rightarrow B, A \rightarrow C$ and $A \rightarrow D$. The change in internal energies during these processes are taken as $E_{AB}, E_{AC}$ and $E_{AD}$ and the work done as $W_{AB}, W_{AC}$ and $W_{AD}$. The correct relation between these parameters is:

The heat energy absorbed by a system in going through a cyclic process shown in the figure is:

Work done in the cyclic process shown in the figure is ...........

The $P-V$ diagram of an ideal gas is as shown. Find the work done by the gas in the $ABCD$ process.