How do capacitors store electrical energy?

Capacitors store electrical energy by accumulating an electric charge on two separate conductive plates separated by an insulator.

A capacitor is a simple device designed to store electrical energy in an electric field. It consists of two conductive plates, usually made of metal, which are separated by an insulating material known as a dielectric. When a voltage, or electrical pressure, is applied across the plates, one plate accumulates positive charge while the other accumulates an equal amount of negative charge. This separation of charge creates an electric field between the plates, and it is in this field that the energy is stored.

The amount of energy a capacitor can store is determined by its capacitance, which is a measure of how much charge the capacitor can hold per unit of voltage. Capacitance is directly proportional to the surface area of the plates and inversely proportional to the distance between them. This means that a larger plate area or a smaller distance between the plates will result in a higher capacitance and therefore a greater energy storage capacity.

The dielectric material also plays a crucial role in the energy storage process. It not only separates the plates to prevent a direct electrical connection, but also enhances the capacitor's ability to store charge. Different materials have different dielectric constants, which affect the amount of charge a capacitor can hold. The higher the dielectric constant, the higher the capacitance and the more energy the capacitor can store.

In summary, capacitors store electrical energy by accumulating charge on two separate plates. The amount of energy they can store is determined by the size and separation of the plates, as well as the properties of the dielectric material used.