Which of the following processes exhibits an increase in internal energy?

$A$ certain system is exothermic by $260 \ kJ$ and does $10 \ kJ$ of work. What is the change in internal energy (in $kJ$)?

The reaction in which $\Delta H > \Delta U$ is

$A$ gas present in a cylinder expands against a constant pressure of $1 \, atm$ from a volume of $2 \, L$ to a volume of $6 \, L$. In doing so,it absorbs $800 \, J$ of heat from the surroundings. The change in internal energy of the process is ..... $J$.

One mole of an ideal gas at $27^oC$ is allowed to expand reversibly and adiabatically. If the work done by the system is $3 \, kJ$,then the final temperature of the gas will be ......$K$. (Given: $C_v = 20 \, J/K \cdot mol$)

Assertion : For an isothermal reversible process $Q = -W$,i.e.,work done by the system equals the heat absorbed by the system.
Reason : Enthalpy change $(\Delta H)$ is zero for an isothermal process.