An electric heater supplies heat to a system at a rate of $100\;W.$ If the system performs work at a rate of $75\;J/s,$ at what rate (in $J/s$) is the internal energy increasing?

$1 \ cc$ of water at its boiling point $(100^{\circ} \ C)$ is converted into steam by supplying $540 \ \text{calories}$ of heat. The volume of steam is $1671 \ cc$. If atmospheric pressure is $1.013 \times 10^5 \ \text{Nm}^{-2}$ and $J = 4.18 \ \text{joule/cal}$, the approximate value of heat required to overcome the molecular attraction is ........ $\text{cal}$.

$1\;g$ of water,of volume $1\;cm^{3}$ at $100^{\circ}C$,is converted into steam at the same temperature under normal atmospheric pressure $(=1 \times 10^{5}\;Pa)$. The volume of steam formed equals $1671\;cm^{3}$. If the specific latent heat of vaporisation of water is $2256\;J/g$,the change in internal energy is.....$J$.

The first law of thermodynamics is concerned with the conservation of

State the first law of thermodynamics and write its limitations.

When $110 \ J$ of heat is supplied to a system and the change in internal energy is $40 \ J$,the work done is .......... $J$.