What role does a relay play in an electrical circuit?

A relay is an electromechanical switch that allows a low-power signal to control a high-power circuit. This is achieved by using an electromagnet to open or close the contacts of the relay, enabling it to manage larger currents that would otherwise be beyond the capacity of the smaller control circuit.

In a typical application, when a small current flows through the relay's coil, it generates a magnetic field that actuates the switch, thus either connecting or disconnecting the power to the load. This functionality is crucial in many electrical systems, especially for safety and efficiency, as it allows one control circuit to manage multiple larger loads without requiring a direct high-current connection between them.

The other options refer to different electrical functions. Converting AC to DC power involves rectification, which is not the primary function of a relay. Power storage relates to capacitors or batteries, which serve to hold electrical energy rather than control circuits. Increasing voltage is the purpose of transformers, which work on fundamentally different electrical principles than relays. Thus, utilizing a relay effectively demonstrates its role in controlling larger current circuits with a smaller current signal.