What does a capacitor do when connected to an AC circuit?

A capacitor in an AC circuit plays a crucial role in managing the flow of electrical energy. When connected to an alternating current (AC) source, the capacitor charges and discharges with the alternating cycle of the voltage. This means that it stores electrical energy temporarily when the voltage is positive and releases it back into the circuit when the voltage reverses, effectively cycling through energy storage and release with each AC cycle.

This characteristic of capacitors is leveraged in various applications, including filtering out voltage spikes, smoothing out fluctuations in power supply, and providing reactive power in AC circuits to support inductive loads. The ability to store and release energy allows capacitors to impact the phase relationship between current and voltage, which is critical in alternating current applications.

This operational principle differentiates capacitors from other components, such as resistors, which dissipate energy instead of storing it, or rectifiers, which convert alternating current to direct current. Understanding this function is essential for effectively using capacitors in electrical and electronic circuits.