How do capacitors utilize electric fields to store energy?

Capacitors store energy by creating an electric field between two 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 separated by an insulator, also known as a dielectric. When a voltage is applied across the plates, an electric field is created between them. This electric field is the key to how a capacitor stores energy.

The process begins when a voltage source, such as a battery, is connected to the capacitor. The battery causes electrons to accumulate on one plate of the capacitor, creating a negative charge. The other plate loses electrons to the battery, creating a positive charge. This separation of charges creates an electric field between the two plates. The strength of this electric field is directly proportional to the amount of charge stored on the plates and inversely proportional to the distance between the plates.

The energy stored in the capacitor is in the form of an electric field created by the separated charges. This energy can be released when the capacitor is discharged, i.e., when a conductive path is provided between the two plates. The electrons will move from the negatively charged plate to the positively charged plate, neutralising the charges and collapsing the electric field. The energy stored in the electric field is then converted back into electrical energy.

The amount of energy a capacitor can store is determined by its capacitance and the voltage applied to it. The capacitance is a measure of how much charge a capacitor can store per unit voltage. It depends on the surface area of the plates, the distance between them, and the properties of the dielectric material. The larger the surface area and the smaller the distance, the higher the capacitance and the more energy the capacitor can store. Similarly, the higher the applied voltage, the more charge the capacitor can store and the more energy it can hold.

In summary, capacitors utilise electric fields to store energy. When a voltage is applied, charges separate and create an electric field between the plates of the capacitor. This electric field holds the energy until the capacitor is discharged.