The first law of thermodynamics states that:

The first law of thermodynamics is given by:

When a system is taken from state $a$ to state $c$ along a path $abc$,it is found that $Q = 80 \ cal$ and $W = 35 \ cal$. Along path $adc$,$Q = 65 \ cal$. The work done $W$ along path $adc$ is: (in $cal$)

State the first law of thermodynamics and write its limitations.

If $150 \ J$ of heat is added to a system and the work done by the system is $110 \ J$,then the change in internal energy will be .......... $J$.

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 ...... $J$.