- What is a magnet?
- Characteristics of a magnet
- How do magnets work?
- Types of magnets
- Magnetic field of a magnet
- Magnet Applications
We explain what a magnet is, what its characteristics are and how they work. In addition, its classification, magnetic field and applications.
A magnet is a material with natural or artificial ferromagnetic properties.
What is a magnet?
A magnet is known as a body of any material capable of producing a magnetic field and attracting towards itself or being attracted towards another magnet or towards any other body of iron, cobalt or other metals ferromagnetic. It is a material with natural or artificial ferromagnetic properties, which generate a continuous magnetic field.
Magnets are some of the first manifestations that thehuman being discovered frommagnetism, known since classical antiquity but only understood in the nineteenth century, when it became known that most of the elements andcompounds acquaintances demonstrated a certain level of magnetism.
Characteristics of a magnet
The line that joins both poles (negative and positive) is called the magnetic axis.
Magnets are bodies that generate a magnetic field around them oriented based on two poles: negative (South) and positive (North). These poles attract with their opposites (positive-negative) but repel their peers (positive-positive or negative-negative).The line that joins both poles is called the magnetic axis.
The magnetic properties of magnets remain intact unless opposing magnetic forces are applied to them, they are increased by temperature (above the Curie Temperature or Curie Point, different according to the element), or if they are subjected to strong blows or from great height. On the other hand, these properties can be temporarily transferred to a sensitive material, by contact (magnetization).
How do magnets work?
The magnetism of magnets is the product of a particular arrangement of electrons (subatomic particles negatively charged) that make up matter. These have an intrinsic rotation about their own axis, which is called spin. Moving charges generate magnetic fields. Therefore, the rotating electrons, that is, charges in movement, they also generate a magnetic field. The introduction ofEnergy on thematter (for example the application of an intense magnetism of the opposite type or heat that raises the temperature very much) destroys the magnetism, since it alters the delicate balance of theelectrons.
In the case of induced magnets (magnetized substances) the effect is similar: when subjected to a magnetic field by contact, their electrons are arranged in the same direction and reproduce the magnetic field for some time.
Types of magnets
Natural magnets are made up of mixtures of magnetite and other minerals.
There are three types of magnets, classified according to their nature in:
- Natural magnets. Generally composed of mixtures Magnetite (ferrofellite or morpholite, composed of ferric oxides) and other terrestrial minerals, naturally possess magnetic properties. The main magnetite deposits are in Sweden (Falun, Dalarna province), Norway (Arendal), France (Plestin-les-Gréves, Brittany) and Portugal (Sao Bartolomé, Nazaré).
- Permanent artificial magnets. Materials sensitive to magnetism that, after being rubbed with magnetite, replicate their ferromagnetic properties for a long period of time until eventually losing them.
- Temporary artificial magnets. Magnetically sensitive materials that, after being rubbed with magnetite, replicate their ferromagnetic properties, only for a very short period of time.
- Electromagnets. They are coils of wire that are wound around a magnetic core made of a ferromagnetic material such as iron. Through the coils circulates electricity, generating a electric field Y magnetic around it. The iron magnetic core concentrates the magnetic flux and makes a stronger magnet. This phenomenon lasts only as long as electricity circulates.
Magnetic field of a magnet
A magnetic field is the region of space around a magnet in which its magnetic forces manifest and act, interacting (attracting or repelling) ferromagnetic objects, electric flow and other magnets within the field.
It is usually represented by lines of force, which are curved arrows that indicate the vector direction of the magnetic force in the field. The shape and direction of these lines will depend on the shape of the magnet, and they have their greatest intensity in the region of the poles.
Our planet Earth It has a magnetic field similar to that of magnets, since its iron core acts as a large mass of charged particles in motion. For this reason, the needles of the compasses are aligned with the north pole. This terrestrial magnetic field also defends us from solar electromagnetic emissions, known as "solar wind."
Magnets are usually attached to various handicrafts or tourist souvenirs for sale.
Magnets have played various roles in our civilization since ancient times and today are an indispensable element in the electronics and electricity. Some of its most popular applications are:
- Manufacture of magnetic tapes. In the electronics and computing, magnetism allows the storage of information through iron oxides whose particles, susceptible to ordering by the magnetic field, can be read with the binary code.
- Electric transformers. Using coils and electromagnets, electrical current can be modulated to rapidly change electromagnetic fields. This principle is central to modern electrical transmission and applies to radios, loudspeakers, and other appliances as well.
- Alternating current motors. These motors are a type of electromagnet, since rotating magnets move the rotors with their magnetic fields.
- Magnetic suspension. Large and powerful magnets are used in the magnetic suspension of trains and other vehicles, as well as in magnetic industrial cranes.
- Craft use. Magnets are usually attached to various handicrafts or tourist souvenirs for sale, under the premise that when tourists return home they will place it on the metal surface of their refrigerator.