How do capacitors and inductors behave in AC circuits?

Capacitors and inductors behave differently in AC circuits than in DC circuits.

In AC circuits, capacitors and inductors exhibit unique behaviours due to the alternating nature of the current. Capacitors store energy in an electric field and can block DC current while allowing AC current to pass through. The reactance of a capacitor varies inversely with frequency, meaning that as the frequency increases, the capacitor's impedance decreases. This property is utilised in AC circuits to filter out unwanted frequencies and to store energy.

Inductors, on the other hand, store energy in a magnetic field and can block AC current while allowing DC current to pass through. The reactance of an inductor varies directly with frequency, meaning that as the frequency increases, the inductor's impedance increases. This property is utilised in AC circuits to filter out unwanted frequencies and to store energy.

In AC circuits, capacitors and inductors can also be used together to create resonant circuits. These circuits can be tuned to a specific frequency, allowing them to selectively filter out unwanted frequencies and amplify desired ones. This property is utilised in radio receivers and transmitters, where resonant circuits are used to select specific frequencies.

In summary, capacitors and inductors behave differently in AC circuits than in DC circuits. Their unique properties are utilised in AC circuits to filter out unwanted frequencies, store energy, and create resonant circuits.