What function does a triac serve in an electrical circuit?

A triac serves as a semiconductor device that can control the flow of electrical power in an AC circuit by turning on and off equipment. It operates by switching the current flow, allowing it to manage the power delivered to various loads, such as motors, lights, and appliances. When the triac is triggered by a gate signal, it allows current to flow through it until the current drops to zero, at which point it turns off. This capability of rapidly switching states enables efficient control of electrical devices, making triacs valuable in applications like dimmers, motor speed controls, and solid-state relays.

In contrast, options like regulating voltage or filtering signals do not accurately describe the primary function of a triac. While voltage regulation usually involves different components such as voltage regulators, filtering signals pertains to capacitors or inductors used to remove unwanted frequencies from a signal. Additionally, storing electrical energy is the role of components like capacitors or inductors, rather than a triac, which instead focuses on control rather than storage.