What is the role of a capacitor in electrical engineering?

The role of a capacitor in electrical engineering is to store an electrical charge. Capacitors are fundamental components used in various electronic circuits to temporarily hold energy in the form of an electric field. When a voltage is applied across the terminals of a capacitor, it accumulates charge; the amount of charge the capacitor can store depends on its capacitance value and the voltage applied.

Capacitors can be utilized in numerous applications, such as filtering signals in power supply circuits, smoothing out fluctuations in voltage, and providing energy storage for applications like camera flashes and audio systems. Their ability to release stored energy quickly allows them to serve important functions, including timing and signal processing.

The options regarding increasing voltage, converting alternating current to direct current, and regulating temperature describe functions performed by other electrical components or systems but do not pertain to the fundamental operation of capacitors. For instance, transformers increase voltage, rectifiers convert AC to DC, and thermistors or other devices handle temperature regulation. Thus, the primary role of a capacitor remains as a device for storing electrical charge.