When the iron core is inserted inside the power thread tube, the iron core is magnetized by the magnetic field of the power pipe tube. The magnetic core after magnetization has also become a magnet, so that the two magnetic fields are superimposed, which greatly enhances the magneticity of the thread tube. In order to make the electromagnet magnetic more magnetic, the iron core is usually made into a hoof shape. However, pay attention to the opposite of the coil on the hoof -shaped core, on one side, and the other side must be clockwise. If the two coils are performed to the iron core, the magnetization of the two coils will offset each other, causing the iron core to be not magnetic. In addition, the core of the electromagnetic iron is made of soft iron, and it cannot be made of steel. Otherwise, once the steel is magnetized, it will maintain magneticity for a long time and not be magnetic, then the strength of its magnetism cannot be controlled with the size of the current, and the advantages of losing the electromagnet should be lost.

Electromagnetic is a device that can generate magnetic power through the current. It is a non -permanent magnet and can easily start or eliminate its magnetic nature. For example: Large cranes use electromagnets to lift abandoned vehicles.

When the current passs through the wire, a magnetic field will be generated around the wire. When applying this nature, when the current through the thread tube, it will be made into a uniform magnetic field within the thread tube. Assuming that the ferromagnetic substance is placed in the center of the thread tube, the iron magnetic substance will be magnetized and will greatly enhance the magnetic field.

Generally speaking, the magnetic field produced by electromagnets is related to the size of the current, the number of coils and the iron magnet of the center. When designing electromagnets, it will focus on the distribution of the coil and the selection of ferromagnets, and use the current to control the magnetic field. Because the material of the coil has resistance, it limits the magnetic field size of the electromagnet, but with the discovery and application of superconductors, it will have the opportunity to surpass existing restrictions.