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

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

One mole of an ideal monoatomic gas is taken round the cyclic process $MNOM$. The work done by the gas is (in $p_0 V_0$)

An ideal gas undergoes the cyclic process $abca$ as shown in the given $P-V$ diagram. It rejects $50 \,J$ of heat during $ab$ and absorbs $80 \,J$ of heat during $ca$. During $bc$, there is no transfer of heat and $40 \,J$ of work is done by the gas. What should be the area of the closed curve $abca$ (in $\,J$)?

$A$ thermodynamic system is taken through the cycle $PQRSP$ as shown in the $P-V$ diagram. The net work done by the system is ....... $J$.

In the following figures $(a)$ to $(d)$,the variation of volume with change of pressure is shown. The gas is taken along the path $A B C D A$. The change in internal energy of the gas will be .......