When $1500 \ J$ of heat is supplied to a gas at a constant pressure of $2.5 \times 10^{5} \ N/m^{2}$,the volume increases by $2.5 \times 10^{-3} \ m^{3}$. The increase in the internal energy of the gas is ..... $J$?

In how many ways can the internal energy of a system be changed?

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 $cal$)

In a thermodynamic process,the pressure of a fixed mass of gas is changed in such a manner that the gas releases $30 \ J$ of heat and $18 \ J$ of work is done on the gas. If the initial internal energy of the gas was $60 \ J$,then the final internal energy will be ..... $J$.

The internal energy change in a system that has absorbed $2 \; kcal$ of heat and done $500 \; J$ of work is ...... $J$.

$Assertion:$ The heat supplied to a system is always equal to the increase in its internal energy.
$Reason:$ When a system changes from one thermal equilibrium to another,some heat is absorbed by it.