If the heat given to a system is $35 \ J$ and the work done on the system is $15 \ J$,then the change in the internal energy of the system is ... $J$?

$A$ gas absorbs $18 \ J$ of heat and work done on the gas is $12 \ J$. Then the change in internal energy of the gas is: (in $J$)

The latent heat of vaporisation of water is $2240 \, J/g$. If the work done in the process of expansion of $1 \, g$ of water is $168 \, J$,then the increase in internal energy is ....... $J$.

An electric appliance supplies $6000 \, J/min$ of heat to the system. If the system delivers a power of $90 \, W$,how long (in $sec$) would it take to increase the internal energy by $2.5 \times 10^{3} \, J$?

$A$ source supplies heat to a system at the rate of $1000 \, W$. If the system performs work at a rate of $200 \, W$,the rate at which the internal energy of the system increases is $....... \, W$.

$1\,kg$ of water at $100^{\circ}C$ is converted into steam at $100^{\circ}C$ by boiling at atmospheric pressure. The volume of water changes from $1.00 \times 10^{-3}\,m^3$ as a liquid to $1.671\,m^3$ as steam. The change in internal energy of the system during the process will be $........kJ$ (Given latent heat of vaporisation $= 2257\,kJ/kg$. Atmospheric pressure $= 1 \times 10^5\,Pa$)