Heat is given to an ideal gas in an isothermal process. Then

$Assertion :$ In an isothermal process,the whole of the heat supplied to the body is converted into internal energy.
$Reason :$ According to the first law of thermodynamics,$\Delta Q = \Delta U + P\Delta V$.

When heat is given to a gas in an isothermal change,the result will be

The work done in doubling the volume of $5$ moles of an ideal gas at a constant temperature of $500 \, K$ is ....... $J$.

Does the internal energy of an ideal gas change in an isothermal process?

Two ideal gases $A$ and $B$ of the same number of moles expand at constant temperatures $T_1$ and $T_2$ respectively such that the pressure of gas $A$ decreases by $50 \%$ and the pressure of gas $B$ decreases by $75 \%$. If the work done by both the gases is same, then $T_1: T_2$ is: