It is worth noting that the magnets are divided into several classes. There are permanent magnets is, as a rule, pieces of a specific metal alloy, possessing a certain magnetism without outside influence. But there are also electromagnets. This technical devices in which a magnetic field is generated by conducting electric current through a special coil.
Of the permanent magnets to the category of powerful can be attributed only to neodymium. With a relatively small size, they are simply stunning magnetic characteristics. First, their magnetic properties, they lose only 1% for a hundred years. Second, despite its relatively small size, they have a huge magnetic force. Neodymium magnets are made artificially. To create the necessary rare earth metal neodymium. Also used iron and boron. The resulting alloy is magnetized in a magnetic field. In the end, the neodymium magnet is ready.
In industry, widely used in powerful electromagnets. Their design is much more complicated than that of permanent magnets. To create a strong electromagnet required coil consisting of windings of copper wire and iron core. Magnetic force in this case depends on the current drawn through the coil and number of turns of wire in the winding. It is worth noting that at a certain current strength the magnetization of the iron core undergoes saturation. Therefore, the most powerful industrial magnets are manufactured without him. Instead, you add an additional number of turns of wire. The most powerful industrial magnets with iron core the number of turns of wires rarely exceeds ten thousand per meter, and used the current is two amperes.