Which of the following relations is correct for an isochoric process?

Which one of the following equations specifies an isochoric process?
$[Q = \text{heat supplied, } \Delta p = \text{change in pressure, } \Delta V = \text{change in volume, } \Delta T = \text{change in temperature}]$

$A$ frictionless piston-cylinder based enclosure contains some amount of gas at a pressure of $400 \text{ kPa}$. Heat is transferred to the gas at constant pressure in a quasi-static process. The piston moves up slowly through a height of $10 \text{ cm}$. If the piston has a cross-sectional area of $0.3 \text{ m}^2$, the work done by the gas in this process is: (in $\text{ kJ}$)

The ratio of specific heats of a gas is $\gamma$. The change in internal energy of one mole of the gas, when the volume changes from $V$ to $2V$ at constant pressure $p$, is:

The $P-V$ diagram for an ideal gas in a piston-cylinder assembly undergoing a thermodynamic process is shown in the figure. The process is

$dQ$ is the heat energy supplied to an ideal gas under isochoric conditions. If $dU$ and $dW$ denote the change in internal energy and the work done respectively,then: