A device having an iron core inside and having a magnetic coil like a magnet is called an electromagnet. Usually made into strips or hooves. The iron core is made of soft iron or silicon steel which is easily magnetized and easily disappears. Such an electromagnet is magnetic when energized, and disappears after power is turned off.

2. Advantage

Electromagnets have many advantages: the presence or absence of magnetism can be controlled by on/off current; the magnitude of magnetism can be controlled by the strength of the current or the number of turns of the coil; the magnitude of the resistance control current can also be changed to control the magnetic size; The magnetic pole can be controlled by changing the direction of the current, and so on. 

3 Application

Electromagnets have an extremely wide range of applications in everyday life. Electromagnets are an application of current magnetic effects (electro-magnetic) and are closely related to life, such as electromagnetic relays, electromagnetic cranes, automatic control machines, maglev trains, etc.