magnetic induction

Production of magnetic properties in unmagnetized iron or other ferromagnetic material when it is brought close to a magnet. The material is influenced by the magnet's magnetic field. The magnetic lines of force pass through the material causing its particles to align themselves parallel to the lines of the magnetic field. The induced magnetism may be temporary, disappearing as soon as the magnet is removed, or permanent, depending on the nature of the material and the strength of the magnet.

Electromagnets make use of temporary induced magnetism to lift sheets of steel; the magnetism induced in the steel by the approach of the electromagnet enables it to be picked up and transported. To release the sheet, the current supplying the electromagnet is temporarily switched off and the induced magnetism disappears.