Which of the following processes exhibits $\Delta U = 0$?

Under isothermal condition,a gas at $300 \; K$ expands from $0.1 \; L$ to $0.25 \; L$ against a constant external pressure of $2 \; bar$. The work done by the gas is .... [Given that $1 \; L \; bar = 100 \; J$]

For an adiabatic change,which of the following is true?

Work done during isothermal expansion of one mole of an ideal gas from $10 \,atm$ to $1 \,atm$ at $300 \,K$ is.....$J$

In an irreversible expansion of a gas,the work done by the gas is given by.....

Which among the following is $NOT$ an intensive property?