Which component of an electric circuit acts as an electrically operated switch?

The component that acts as an electrically operated switch in an electric circuit is a relay. A relay is an electromagnetic switch that uses an electromagnet to mechanically operate a switching mechanism. When an electrical current flows through the coil of the relay, it creates a magnetic field that attracts a movable armature, closing or opening the circuit connected to it.

This allows a low-power signal to control a larger load circuit, making relays particularly useful in applications where it is necessary to separate control and power circuits. For instance, relays can be employed in automation systems, where they enable low-voltage inputs to control high-voltage outputs safely.

In contrast, capacitors store and release electrical energy but do not act as switches. Transformers are used for changing voltage levels in an AC circuit but do not function as switches either. Diodes are semiconductor devices that allow current to flow in one direction only but do not provide switching capability like relays do. Therefore, the relay clearly stands out as the component that serves as an electrically operated switch in an electric circuit.