What is the primary function of a relay in an electrical circuit?

The primary function of a relay in an electrical circuit is to act as an electrically operated switch. A relay allows a low-power circuit to control a high-power circuit without direct electrical contact between the two, enabling remote operation of devices. When a small current flows through the coil of the relay, it generates a magnetic field that closes (or opens) the contacts, thus switching the connected load on or off. This operation is crucial in many applications, including automation and control systems, where it is essential to control larger currents or voltages safely and efficiently.

The design and functionality of a relay allow it to isolate the control side from the load side, providing both safety and control capabilities. While increasing current flow, measuring voltage levels, and storing electrical energy are all important functions in different electrical components, they are not the primary roles of a relay. Instead, the relays focus on enabling circuit control through the switching mechanism they provide.