What are the functions of a capacitor in electrical circuits?

The primary function of a capacitor in electrical circuits is to store and release electrical energy. This capability allows capacitors to play essential roles in various applications, such as smoothing out fluctuations in power supply (filtering), providing bursts of energy when needed (as in power supply systems), and in timing applications (where they charge and discharge at controlled rates).

When connected to a power source, a capacitor accumulates charge on its plates, creating an electric field that stores energy. When the circuit requires additional energy, the capacitor can quickly discharge this stored energy, which is crucial for maintaining stable operation in many electronic devices.

This fundamental behavior of capacitors underlines their importance in a wide range of electrical and electronic circuits, including power conditioning, signal processing, and timing applications. Other options may describe functions that are more closely associated with other components, such as surge protection devices for electrical surges or voltage regulators for voltage control.