How does a relay operate in an electrical circuit?

A relay operates by opening or closing a circuit in response to an electrical signal, which is the defining characteristic of how relays function. When a small current flows through the coil of the relay, it creates a magnetic field that either pulls in or releases a mechanical switch inside the relay. This action either completes or breaks the circuit, allowing control over larger currents or voltages that the relay is operating.

This function is crucial in various applications such as automation and control systems where a low power signal needs to manage larger loads safely. The ability of a relay to control circuits with an external signal without requiring human intervention makes it vital in elevator systems and other machinery that depend on precise control of electrical paths.

In contrast, options related to amplifying signals, storing energy, or generating power do not align with the primary function of a relay. Relays do not amplify signals, they switch states; they do not store energy like capacitors; and they do not act as sources of electrical power like generators. Understanding how relays operate is fundamental to grasping broader concepts in electrical control systems.