An ideal monoatomic gas is taken round the cycle $12341$ shown in the figure ( $p\,-\,V$ diagram). The work done in one cycle is ?

For one complete cycle of a thermodynamic processes on a gas as shown in $P-V$ diagram. Which is true

$Assertion :$ The heat supplied to a system is always equal to the increase in its internal energy.
$Reason :$ When a system changes from one thermal equilibrium to another, some heat is absorbed by it.

In the $P-V$ diagram shown, the gas does $5\, J$ of work in isothermal process $ab$ and $4\,J$ in adiabatic process $bc$.   …. $J$ will be the change in internal energy of the gas in straight path $c$ to $a$ ?

The figure shows the $P-V$ plot of an ideal gas taken through a cycle $ABCDA$. The part $ABC$ is a semi-circle and $CDA$ is half of an ellipse. Then,

$(A)$ the process during the path $\mathrm{A} \rightarrow \mathrm{B}$ is isothermal

$(B)$ heat flows out of the gas during the path $\mathrm{B} \rightarrow \mathrm{C} \rightarrow \mathrm{D}$

$(C)$ work done during the path $\mathrm{A} \rightarrow \mathrm{B} \rightarrow \mathrm{C}$ is zero

$(D)$ positive work is done by the gas in the cycle $ABCDA$