Mineral magnetite and its magnetic properties have been discovered and used already in the ancient Rome, even in ancient China. The magnet has become a very important commercial gadgets, mainly because of its ability to navigate the floating pad in the northsouth direction. After discovering this characteristic of the magnet, sailors no longer have to rely solely on the stars and lighthouses on the coast; The direction of the voyage was determined by the map and the compass, which was determined by the north-south direction of the magnetite.

The magnetite is a magnetized iron ore. However, not all iron ore on Earth is magnetized. The emergence of magnetic properties of iron ore scientists explain in several theories. The preferred explanation is that the magnet was created by gradually strengthening the layers containing the iron through a heavy body. When the magnetite cooled was heavily influenced by the Earth‘s magnetic field or it could have been struck by tiny lightning blades. If the magma containing the iron was cooled quickly, it would not be influenced by the Earth‘s magnetic field and the iron ore was formed without magnetic properties.

In the sand and in the soil it is possible to find a relatively large amount of trace fragments of magnetite. These fragments can be observed by means of an iron object (or even a magnet) which will attract fragments of magnetic properties. To find a larger fragment of magnetite is rather rare, however, magnets can be produced.

Magnetism in iron and steel articles

Iron and steel items can obtain temporary magnetism by friction using a permanent magnet. Thin, small, iron items (such as nails, pins) lose magnetism already in a few minutes. Steel objects will keep magnetism longer. Even the steel loses magnetism more slowly, it is more difficult to create it – there is a need for longer friction of the object by a magnet to obtain magnetic properties. When creating magnetic properties you need to be careful that one stroke was completed and the magnet was lifted from the end of the nail until we start another move from the header of the nail. After a few minutes after the magnet has been created, its intensity of the magnetic field begins to fade visibly. It drops equally fast no matter how many times we have magnetized it. The second way to make a magnet is to leave objects that are magnetically attracted close to it for a long time.

Industrial magnets

Industrial magnets are usually made of steel and are magnetized by electric shock. Therefore, magnetic properties can also be obtained through the operation of electric current. We wrap the wire around the wedge and connect it to the electrical circuit. Immediately after the electrical circuit is plugged, the nail gets magnetic properties. Such a magnet we call an electromagnet. The intensity of the magnetic field generated depends on the size of the electrical current transmitted by the wire. By thickened the wire around the wedge we achieve a better effect even at low levels passing through the electric current. By disconnecting the electric current, the iron nail loses magnetic properties. The principle of the formation of Electromagnet consists in the fact that any wire that crosses the electrical current creates a magnetic field in its surroundings.

Magnetic Earth field

Magnetic properties in the compass can be used because Earth behaves like a large magnet. The reason for the existence of the Earth‘s magnetic field is explained by several hypotheses. One of these explanations tells you that while some parts inside the earth are moving slower, others are moving faster. The friction of these parts will emit electrical particles and the effect of electric current is generated by a magnetic field. Since the Earth‘s core consists primarily of iron and nickel (magnetic materials), a very large magnet is created (the magnetic field is created around the earth). The maps are adjusted for orientation by magnet, the classical map shows the space so that its perpendicular direction represents the north-south direction. Some maps may have a different orientation, they usually also contain a direction rose, by which the northern direction on the map can be identified. Since the North Geographic Pole is about 1,600 km from the North Magnetic Pole, and the South Geographic is about 2400 km away from the Magnetic Pole, it is possible to navigate with high precision with the help of a compass.

Theory magnetic domain

Although the magnetic properties of some metals have been used for centuries, science has not yet fully explained this phenomenon. It is interesting to note the fact that a magnet can be divided into smaller parts, with each section having its north and south pole. These properties are explainedby the theory of magnetic domains. According to this theory, magnets consist of a large number of small clusters of atoms, called domains. It is possible to identify the north and south magnetic poles within one cluster. These clusters are stored randomly, unordered in the material. However, if we start to rub the object in one direction, the domains start to be arranged in one direction and a magnet is created. The heating of the magnet causes an increase in the motion of the atoms and thus the ordered parts can be dispersed (thereby losing the magnetic property). Similarly, a magnet may lose its magnetic properties by banging it against a hard surface.

Magnets attract only metal objects, but not all of them. In addition to iron, they also attract cobalt and nickel. The other metals are not attracted by the magnet. For example, stainless steel does not attract a magnet. A visual distinction between metals attracted by magnets and those not attracted by a magnet is often not possible. Metals can be treated with an anti-corrosion coating of another metal. Cans are usually made of steel (attracted by a magnet) and are coated with an anti-corrosion surface that is not attracted by the magnet itself. Most pins are made of steel and can be picked up with a magnet, but some (even if they look the same) can be made of stainless steel or brass, which means they are not attracted by the magnet. The same goes for keys, spoons, or small fasteners (nails, screws, nuts, etc.).

Magnetic field

Magnetic properties only appear at a specific distance from the magnet, we say there is a magnetic field around the magnet.The magnetic field may be of varying intensity, equivalent to attracting objects from a greater or lesser distance. Although we cannot see the magnetic field, it can be observed mediated, for example, with iron scobs. Most scobsis collected around magnetic poles. Scobsis arranged in specific lines that follow the so-called field lines – direction of action of magnetic force. Although the scobsare not arranged at some distance from the magnet, this does not mean that the magnetic field does not work here. It is only very weak to move the iron scobs. At some distance from the magnet, the field is so weak that we cannot detect it – it is virtually non-existent. Different magnets have a magnetic field extending at different distances (acting on objects and other magnets at different distances). In addition to this, the magnets also vary in magnetic field strength. This is manifested, for example, by the fact that magnets with a high magnetic field strength maintain a greater weight of iron objects. The magnitude and intensity of the magnetic field of the magnet are two different properties. This means that the magnet can be small (attracting objects from a small distance) but very intensely (retaining a large number of iron objects). The magnetic field also acts through obstacles and the magnetic field itself cannot be reduced or weakened. This means that if an obstacle is inserted between the magnet and the object attracted by the magnet, the magnet will attract the object if it is within its magnetic field.