First law of thermodynamics is represented by

$A$ 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:

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?

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 ... $J$?

$A$ monoatomic gas of $n$ moles is heated from temperature $T_1$ to $T_2$ under two different conditions: $(i)$ at constant volume and $(ii)$ at constant pressure. The change in internal energy of the gas is

$A$ diatomic gas has an initial internal energy of $80 cal$. $A$ work of $18 cal$ is done on the gas and the gas releases heat energy of $42 J$. The final internal energy of the gas is