What is the ratio between the charge on either plates of capacitor and the potential difference between the plate?

The ratio between the charge on either plate of a capacitor (Q) and the potential difference (V) across the plates is given by the capacitance (C) of the capacitor, expressed as ( C = \frac{Q}{V} ). This means that the capacitance is a measure of how much charge a capacitor can store per unit of voltage applied. Therefore, the ratio ( \frac{Q}{V} ) is constant for a given capacitor and is equal to its capacitance.