What happens to the capacitance when one plate of a capacitor is moved further away from the other plate?

When one plate of a capacitor is moved further away from the other plate, the capacitance decreases. Capacitance is defined as the ability of a capacitor to store charge per unit voltage and is mathematically expressed by the formula (C = \frac{εA}{d}), where (C) is capacitance, (ε) is the permittivity of the dielectric material between the plates, (A) is the area of one of the plates, and (d) is the distance between the plates.

As the distance (d) increases (when one plate is moved away), the capacitance (C) inversely decreases since the plates are less able to store electric field strength. A larger distance results in a weaker electric field between the plates for a given voltage, thereby reducing the overall capacitance. Consequently, it requires a higher voltage to achieve the same charge storage as before the plates were moved apart.

This understanding is fundamental in capacitive circuits, where the capacitance directly affects the behavior of capacitors in timing, filtering, and energy storage applications.