What happens when you move one plate of a capacitor further away from the other?

When you move one plate of a capacitor further away from the other, the capacitance decreases. Capacitance is defined as the ability of a capacitor to store charge per unit voltage across its plates, and it is influenced by the distance between those plates.

The relationship between capacitance (C), the area of the plates (A), the distance between them (d), and the permittivity of the dielectric material (ε) is given by the formula:

[ C = \frac{\epsilon \cdot A}{d} ]

In this formula, as the distance (d) increases while keeping the area (A) and the permittivity (ε) constant, the overall capacitance decreases. This means that with an increased distance between the plates, the capacitor is less able to store charge for a given voltage, resulting in decreased capacitance.

Thus, moving the plates apart directly leads to a decrease in capacitance, making the answer correct.