What is the primary function of a capacitor in a circuit?

The primary function of a capacitor in a circuit is to store and release electrical energy. Capacitors are devices that can accumulate electrical charge, creating an electric field. When a voltage is applied across the capacitor’s plates, it stores energy in the form of an electric field. This stored energy can then be released back into the circuit when needed.

In applications, capacitors provide several benefits, such as smoothing out fluctuations in voltage in power supply circuits, filtering signals in audio and radio equipment, and assisting with starting motors by providing the necessary additional surge of current. This ability to store and subsequently release electrical energy is what fundamentally distinguishes capacitors from other circuit components.

While increasing current flow, converting AC to DC, and measuring voltage are functions associated with different components or systems in an electric circuit, they do not pertain to the core role of a capacitor. Thus, the correct focus is on the capacitor's capability to temporarily store energy, which underlies its utility in various electronic applications.