(N/A) $1$. Isochoric Process: A thermodynamic process in which the volume of the system remains constant $(dV = 0)$ is called an isochoric process. In this process, no work is done by or on the system $(W = 0)$.
$2$. Cyclic Process: A process is called cyclic if the system returns to its initial state after a series of changes. In a cyclic process, the change in internal energy is zero $(\Delta U = 0)$.
$3$. First Law of Thermodynamics: For an ideal gas, the first law of thermodynamics is given by $\Delta Q = \Delta U + \Delta W$, where $\Delta Q$ is the heat supplied to the system, $\Delta U$ is the change in internal energy, and $\Delta W$ is the work done by the system.