Heat is given to an ideal gas in an isothermal process.
$A.$ Internal energy of the gas will decrease.
$B.$ Internal energy of the gas will increase.
$C.$ Internal energy of the gas will not change.
$D.$ The gas will do positive work.
$E.$ The gas will do negative work.
Choose the correct answer from the options given below:

During an isothermal expansion,a confined ideal gas does $-150 \, J$ of work against its surroundings. This implies that

One mole of ${O_2}$ gas having a volume equal to $22.4 \text{ litres}$ at $0^{\circ}C$ and $1 \text{ atmospheric pressure}$ is compressed isothermally so that its volume reduces to $11.2 \text{ litres}$. The work done in this process is ...... $J$.

The specific heat of a gas in an isothermal process is

$A$ piston of mass $M$ is hung from a massless spring whose restoring force law is given by $F = -kx^3$,where $k$ is the spring constant of appropriate dimension. The piston separates the vertical chamber into two parts,where the bottom part is filled with $n$ moles of an ideal gas. An external work is done on the gas isothermally (at a constant temperature $T$) with the help of a heating filament (with negligible volume) mounted in the lower part of the chamber,so that the piston moves up from a height $L_0$ to $L_1$. Calculate the total energy delivered by the filament. (Assume the spring to be in its natural length before heating.)

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