$A$ unit mass of a liquid with volume $V_1$ is completely changed into a gas of volume $V_2$ at a constant external pressure $P$ and temperature $T$. If the latent heat of evaporation for the given mass is $L$,then the increase in the internal energy of the system is:

$A$ gas can be taken from $A$ to $B$ via two different processes $ACB$ and $ADB$. When path $ACB$ is used,$60 \, J$ of heat flows into the system and $30 \, J$ of work is done by the system. If path $ADB$ is used,the work done by the system is $10 \, J$. The heat flow into the system in path $ADB$ is ..... $J$.

$A$ gas is supplied with $1500 \; J$ of heat energy at constant pressure. If the constant pressure of the gas is $2.1 \times 10^{5} \; N/m^{2}$ and the increase in volume is $2.5 \times 10^{-3} \; m^{3}$,then the increase in the internal energy of the gas is ...... $J$.

In a thermodynamic process,the pressure of a fixed mass of a gas is changed in such a manner that the gas releases $30 \,J$ of heat and $10 \,J$ of work is done on the gas. If the initial internal energy of the gas was $10 \,J$,then the final internal energy will be: (in $\,J$)

$A$ thermally insulated rigid container of $1 \,L$ volume contains a diatomic ideal gas at room temperature. $A$ small paddle installed inside the container is rotated from the outside,such that the pressure rises by $10^{5} \,Pa$. The change in internal energy is close to ............... $J$.

Which of the following laws of thermodynamics defines the term internal energy?