According to Baidu Library, iron core is an important part of electromagnet, and its size and shape directly affect the performance of electromagnet. Stroke refers to the distance that the electromagnetic coil moves when the electromagnet is energized. According to the principle of electromagnet, when electrified, a magnetic field will be generated in the spiral coil, which can attract the iron core and generate suction between the iron core and the spiral coil. When the stroke increases, the distance between the iron core and the solenoid increases, and the suction force also increases. So the relationship between stroke and iron core is proportional.

DC electromagnet is composed of movable iron core, fixed iron core, coil and yoke. It is endowed with the energy to attract action. Electromagnets belong to the electronic component industry.