What is the primary function of an electrical relay?

The primary function of an electrical relay is to control high current equipment using a smaller control signal, effectively allowing a low-power circuit to manage the operation of a high-power circuit. This is accomplished by using electromagnetism. When a current flows through the coil of the relay, it generates a magnetic field that closes the switch contacts, completing the circuit for the high current application.

This function is particularly useful in various applications where it is necessary to control large loads with small control devices, such as light switches or sensors. In industrial and automotive applications, relays ensure that high current devices, like motors and lights, can be operated safely and efficiently without the need for a human operator to directly manage the high current.

The other functions listed, such as storing electrical energy, amplifying signals, or converting AC to DC, do not accurately represent the role of a relay. While these are indeed important functions in electrical systems, they pertain to different components such as capacitors for energy storage, amplifiers for signal processing, and rectifiers for power conversion.