An indicator diagram is a ...........

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

In the cyclic process given in the $P-V$ diagram,the work done is

In a thermodynamic process,the pressures and volumes corresponding to some points in the figure are $P_A = 3 \times 10^4 \, Pa$,$V_A = 2 \times 10^{-3} \, m^3$,$P_B = 8 \times 10^4 \, Pa$,and $V_D = 5 \times 10^{-3} \, m^3$. In process $AB$,$600 \, J$ of heat is added,and in process $BC$,$200 \, J$ of heat is added to the system. The change in the internal energy in process $AC$ would be .... $J$.

$A$ monoatomic gas is taken along path $AB$ as shown in the $V-P$ diagram. Calculate the change in internal energy of the system.

An ideal gas undergoes a cyclic process as shown in the diagram. The net work done by the gas in the cycle is