The electromagnets are powered through the circuit connected to a source of electricity. The latter process energizes the electromagnets. As a result, the scrap metals or heavy metallic loads are then attracted by the magnets and transported to the desired position. Once the metallic load has been transported to the right place, electricity is switched off from the source leading to loss of energy of the large magnet. Therefore, the metallic load eventually detaches itself from the magnet.
The second application of the relationship between electricity and magnetism is in the movement of electric trains. There are two ways through which an electric rail engine can be supplied with electric power. First, an overhead power source can be integrated in the rail system in order to provide the required source of power. Alternatively, electric rails can be used to supply electric power. The required amount of power is regulated by an onboard transformer. This is similar to the working principle of a substation that runs on wheels. In addition, the driver can regulate the amount of power supplied to the train.