Electromagnets are used in a wide variety of places, e.g. scrap metal businesses to lift car bodies, electric bells, relays and circuit breakers. Depressing a momentary switch will complete a circuit that powers the electromagnet. The cycle is repeated as long as the momentary switch is depressed. Electric Relay A relay is a remote switch. It is often used to turn high-current devices on and off remotely, with a low current in the relay circuit.
Circuit breakers protect circuits and devices from too much current.
The trip switch will stay open after it has been activated. It has to be reset manually after the cause of excess current has been fixed. The Active is the high potential wire. The Neutral is the return wire and Earthed at the distant supply. The Earth wire is the local earth to keep the outer shell of appliances at local Earth.