Opposite poles are attracted to each other, while the same poles repel each other. When you rub a piece of iron along a magnet, the north-seeking poles of the atoms in the iron line up in the same direction. The force generated by the aligned atoms creates a magnetic field. The piece of iron has become a magnet.

Why is iron a good electromagnet?

The best core for an electromagnet is therefore the material with the highest relative permeability. Any material with a relative permeability higher than one will increase the strength of an electromagnet when used as a core. ... This huge relative permeability is why iron is the best core for an electromagnet.

What is magnetized iron?

Ferromagnetism is the basic mechanism by which certain materials (such as iron) form permanent magnets, or are attracted to magnets. ... Only a few substances are ferromagnetic. The common ones are iron, cobalt, nickel and most of their alloys, and some compounds of rare earth metals.