$A$ gas goes from state $A$ to state $B$ via three different paths as shown in the $P-V$ diagram. If $Q_1, Q_2,$ and $Q_3$ are the heat absorbed by the gas along the three paths, then:

In the indicator diagram (shown in the figure),the net amount of work done will be

In the reported figure,the heat energy absorbed by a system in going through a cyclic process is $......\,\pi \text{ J}$.

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

An ideal gas is made to undergo the cyclic process shown in the figure below. Let $\Delta W$ depict the work done,$\Delta U$ be the change in internal energy of the gas,and $Q$ be the heat added to the gas. The signs of each of these three quantities for the whole cycle will be ($0$ refers to no change):

Three moles of an ideal monoatomic gas undergo a cyclic process as shown in the figure. The temperatures of the gas in different states marked as $1, 2, 3$ and $4$ are $400 \ K, 700 \ K, 2500 \ K$ and $1100 \ K$ respectively. The work done by the gas during the process $1-2-3-4-1$ is (universal gas constant is $R$): (in $R$)