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 ....... $J$.

$A$ perfect gas goes from state $A$ to another state $B$ by absorbing $8 \times 10^5 \ J$ of heat and doing $6.5 \times 10^5 \ J$ of external work. It is now transferred between the same two states in another process in which it absorbs $10^5 \ J$ of heat. Then in the second process:

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

The $P-V$ diagram of a system undergoing a thermodynamic transformation is shown in the figure. The work done on the system in going from $A \to B \to C$ is $50 \, J$ and $20 \, cal$ of heat is given to the system. The change in internal energy between $A$ and $C$ is ...... $J$.

During the process $A \rightarrow B \rightarrow C$,the work done is $50 \, J$ and the heat supplied is $20 \, cal$. Find the change in internal energy between $A$ and $C$ in $J$. (in $, J$)

First law of thermodynamics is represented by