PV = constant

The equation PV = constant represents Boyle's Law, which states that the pressure of a gas is inversely proportional to its volume when the temperature is held constant. This means that as the volume of a gas decreases, the pressure increases, and vice versa.

For an adiabatic process, the relation between pressure (P) and volume (V) of a gas is given by PV^γ = constant, where γ is the adiabatic index.