Electromagnets and Their Applications

Electromagnet: A device that utilizes the magnetic effect of electricity to magnetize soft iron. 1. Insert a soft iron rod into the interior of a helical coil, and when the coil is energized with current, the magnetic field within the coil magnetizes the soft iron rod into a temporary magnet. However, when the current is cut off, the magnetism of both the coil and the soft iron rod disappears. 2. The magnetic field generated by the magnetized soft iron rod, combined with the magnetic field within the original coil, greatly enhances the total magnetic field strength, hence the magnetic force of the electromagnet is greater than that of a natural magnet. Pure iron 3. The greater the current in the helical coil and the more turns in the coil, the stronger the magnetic field of the electromagnet. Applications of Electromagnets: 1. Cranes: Industrial-grade powerful electromagnets that, when supplied with high current, can be used to lift steel plates, shipping containers, scrap iron, and more. 2. Telephones: To be introduced in the next section. 3. Ammeters, voltmeters, galvanometers 4. Electric bells, and more.