What are the similarities and differences between electromagnets and permanent magnets

Electromagnets and permanent magnets are similar in that they both generate magnetic fields. The difference between the two is as follows: an electromagnet is a device that generates electromagnetism when energized. A conductive winding that matches its power is wound on the outside of the iron core. This current-carrying coil is magnetic like a magnet, and it is also called an electromagnet.

In order to demagnetize the electromagnet immediately after power failure, we often use soft iron or silicon steel material that demagnetizes faster. Such electromagnets are magnetic when energized, and disappear when the power is turned off. The electromagnet is widely used in our daily life, and the power of the generator has been greatly improved due to its invention.

Extended information:

The principle of electromagnet:

When the iron core is inserted inside the energized solenoid, the iron core is magnetized by the magnetic field of the energized solenoid. The magnetized iron core also becomes a magnet, so that the magnetism of the solenoid is greatly enhanced due to the superposition of the two magnetic fields. In order to make the magnetism of the electromagnet stronger, the iron core is usually made into a hoof shape.

However, it should be noted that the winding direction of the coil on the shoe-shaped iron core is opposite, one side must be clockwise, and the other side must be counterclockwise. If the winding directions are the same, the magnetization of the two coils on the iron core will cancel each other out, so that the iron core is not magnetic.

The core of the electromagnet is made of soft iron, not steel. Otherwise, once the steel is magnetized, it will remain magnetic for a long time and cannot be demagnetized, so the strength of its magnetic properties cannot be controlled by the magnitude of the current, and the advantages of electromagnets will be lost.