Which of the following components is commonly used to store electrical energy for later use?

The correct choice is the capacitor, as it is specifically designed to store electrical energy in an electric field for later use. Capacitors consist of two conductive plates separated by an insulating material, known as a dielectric. When voltage is applied across the plates, an electric charge accumulates, thereby storing energy. This stored energy can then be released quickly when needed, making capacitors essential in various electronic applications, such as smoothing out voltage fluctuations, filtering signals, and providing bursts of power in circuits.

Transformers are primarily used to transfer electrical energy between circuits through electromagnetic induction, rather than storing energy. Resistors, on the other hand, dissipate electrical energy as heat and do not store it. Relays are electromechanical switches that use electrical signals to open or close circuits, but they also do not serve the purpose of energy storage.