Describe the role of a capacitor in an electrical system?

A capacitor serves the critical function of storing and releasing electrical energy within an electrical system. It does this by accumulating electrical charge on its plates when connected to a voltage source, which creates an electric field between them. When the circuit requires energy, the capacitor can discharge this stored energy back into the system. This ability to hold and quickly release energy is utilized in various applications, such as smoothing out voltage fluctuations in power supplies, filtering signals in communication systems, and providing bursts of energy in timing applications.

The other functions implied by the other choices do not accurately represent the role of a capacitor. For instance, while a capacitor can influence voltage levels in a circuit, its primary function is not to increase voltage. Additionally, capacitors do not measure current flow; that role is typically performed by ammeters or other current-sensing devices. Lastly, while capacitors can help mitigate some issues related to overloads (such as serving as part of power factor correction), they are not designed to protect circuits from overloads, a function usually managed by circuit breakers or fuses.