What electrical element temporarily stores energy and smooths voltage fluctuations?

The element that temporarily stores energy and helps smooth voltage fluctuations is a capacitor. Capacitors are designed to hold an electric charge and can release that charge when needed, which allows them to manage and stabilize voltage levels in electrical circuits. This property is particularly useful in power supply applications, where they help to smooth out voltage variations caused by load changes or fluctuations in the supply.

When a capacitor is charged, it stores energy in the form of an electric field. When there is a sudden demand for additional power in a circuit (often referred to as voltage sag), the capacitor can release its stored energy to help maintain the voltage level, thus reducing fluctuations. This ability to store and release energy makes capacitors essential components in various applications, including power filtering, timing circuits, and energy storage systems.

Inductors also store energy, but they do so in a magnetic field rather than an electric field, which is more suited for applications involving current changes rather than voltage stabilization. Transformers are primarily used for altering voltage levels and do not store energy in the same way. Relays are switches controlled by electric currents and do not serve the purpose of energy storage or voltage smoothing. Therefore, the role of a capacitor in temporarily storing energy and managing voltage fluctuations is crucial.