The change in the internal energy of a mass of gas,when the volume changes from $V$ to $2V$ at constant pressure $P$,is (where $\gamma$ is the ratio of specific heat of gas at constant pressure to specific heat at constant volume):

The volume of one mole of the gas is changed from $V$ to $2V$ at constant pressure $p$. If $\gamma$ is the ratio of specific heats of the gas,what is the change in internal energy of the gas?

$A$ total of $48 \,J$ heat is given to one mole of helium kept in a cylinder. The temperature of helium increases by $2^{\circ} C$. The work done by the gas is : (Given,$R=8.3 \,J \,K^{-1} \,mol^{-1}$.) (in $\,J$)

Heat given to a system is $35 \ J$ and work done by the system is $15 \ J$. The change in the internal energy of the system will be ..... $J$.

Assertion : Heat and work are modes of energy transfer to a system resulting in change in its internal energy.
Reason : Heat and work in thermodynamics are state variables.
The correct option among the following is

$1 \,g$ of water at $100^{\circ} C$ is completely converted into steam at $100^{\circ} C$. $1 \,g$ of steam occupies a volume of $1650 \,cc$. (Neglect the volume of $1 \,g$ of water at $100^{\circ} C$). At the pressure of $10^5 \,N/m^2$, the latent heat of steam is $540 \,cal/g$ $(1 \,calorie = 4.2 \,joule)$. The increase in the internal energy (in joule) is: