Magnets! They are everywhere and very much a part of our daily lives but how much do we really know about magnets?
What is a magnet?
Put simply a magnet is a piece of iron or metal with magnetic properties that attracts other iron objects. The simplest of magnets have two poles conventionally designated as the North and South poles. Although we may be very familiar with magnets used for decoration or for advertising purposes, magnets are much more than what we use for paper clips and fridge decorations. There are of several types, they come in all shapes and sizes and they have a wide array of applications.
Types of magnets
There are mainly three types of magnets permanent, temporary and electromagnets.
Permanent Magnets are permanently magnetic. You can’t turn them on or off. They are made out of ferromagnetic materials. Permanent magnets can then be further classified into four smaller groups. Neodymium Iron Boron, Samarium Cobalt, Alnico, Ceramic or Ferrite
Temporary magnets become magnetic when they are in a magnetic field. However, if the field disappears they lose their magnetism. Classic examples are paperclips and iron nails.
Electromagnets are only magnetic when electricity is passed through them. They produce extremely powerful magnetic fields. That is why they are mainly used for industrial purposes. You can create one by wrapping an iron core with a wire carrying electricity. The more wire wrapped around and the stronger the current the more powerful the electric field.
Magnet shape, size and uses
First of all, the shape of a magnet determines the directions of the magnetic fields that surround the magnet. The magnetic field gives a magnet the ability to attract and repel metal objects. The direction of the field surrounding the magnet, in turn, determines the uses of the magnet.
Plus, the magnetic power of a magnet is strongest at the poles. While these opposite poles exert considerable power, the strength of the magnetic field is weaker along the sides of the magnet. Moreover, contrary to the belief that a magnet has just two poles, the shape of a magnet can be altered to increase the number of North and South poles. For example, a “quadrupole” has two North poles and two South poles. A “sextupole”, has six poles; three North poles and three South poles.
That said, know that the shape of a magnet greatly influences its uses. Bar magnets are the most common type of magnets for daily use. For example, they are a vital component in electric guitars and are commonly called guitar magnets. There is magnetic a pickup which consists of a bar magnet wrapped with many turns of fine wire. So if you are a guitar manufacturer it will be easy to find bar magnets as they are very common.
Magnets in the industrial sector are frequently used to separate impure metals during metal recycling or manufacturing, sorting, and magnetic sweeping.
Due to the high strength of electromagnets, they are used in electronic devices like TVs, computers, and Phones. For this same reason, they are also used in on-off applications, such as cranes used for heavy lifting.