How does a capacitor differ from an inductor in a circuit?

A capacitor stores energy in an electric field, while an inductor stores energy in a magnetic field.

In a circuit, a capacitor and an inductor play different roles due to their unique properties. A capacitor is a passive electronic component that stores energy in an electric field. It consists of two conductive plates separated by an insulating material known as a dielectric. When a voltage is applied across the plates, an electric field is created, and energy is stored in this field. The ability of a capacitor to store charge is measured in Farads (F). Capacitors are used in various applications such as filtering noise, tuning resonant circuits, and storing energy in power supplies.

On the other hand, an inductor is another passive electronic component that stores energy in a magnetic field. It is typically a coil of wire. When an electric current flows through this coil, a magnetic field is created around the coil, and energy is stored in this field. The ability of an inductor to store energy in a magnetic field is measured in Henrys (H). Inductors are used in applications such as filtering signals, storing energy in power supplies, and in the tuning of resonant circuits.

The behaviour of capacitors and inductors in a circuit also differs. Capacitors oppose a change in voltage and can block direct current (DC), while allowing alternating current (AC) to pass. This is because the charge stored in the capacitor resists changes in voltage, creating a short-term battery effect.

Inductors, however, oppose a change in current. They allow DC to pass easily but resist AC. This is due to the magnetic field created by the current flow, which resists changes in current.

In summary, while both capacitors and inductors store energy and can be used in tuning and filtering applications, they do so in different ways and have different effects on the current and voltage in a circuit.