Minds Weapon

A magnet is a material that creates a magnetic field, and attracts magnetized materials to it. Contents. 1 history; 2 magnetic materials; 3 properties of magnets. 3.1 magnetic field; 3.2 magnetic torque supermagnet, k & j magnetics, k and j magnetics, vistaprint magnets, magnetic labels, magnet car, vehicle magnets, custom magnets, magnetise, overbandmagnetic name badges, custom refrigerator magnets, first for magnets, magnetic sweeper, whiteboard magnets, personalized magnets, magnets near me, industrial magnets, cylindrical magnet, a magnet, rare earth magnets, magnetic metal, thin magnets, samarium cobalt, earth magnets, magnet shop,

Magnet

Magnet stone is a magnetized iron ore, and it is a primary component of igneous rocks, and it is one of the most widespread minerals in nature. This magnet has been known since ancient times. Because of its magnetic force, which is a force that the magnet acts on atoms of specific substances, which leads to their attraction or repulsion, and from the materials that are affected by the magnet, iron.

Magnet stones were formed in unknown circumstances, but scientists believed that they were formed from black iron oxides and magnetite. As the resistance of these stones keeps them permanently magnetized, and from their theories also that the magnet stones obtained their magnetic strength from the strong magnetic field of lightning strikes ; This supports the idea that magnet stones are present on the surface of the earth and not in its interior, and there are two compounds in nature in the form of stones of natural magnetism: magnetite (Fe 3 O 4 ), and perotite.

The history of the discovery of the magnet

The discovery of the magnet is not considered to be a recent creation, but rather it dates back to ancient times. The Greek and Chinese civilizations and the Olmec peoples who lived in ancient times were able to discover and use it; Where the American scientist John Carlson estimated that the Olmec peoples - who lived before 1000 BC in South America - used magnets to determine directions and build temples, and the world who knew the power of magnetism to iron is the Greek scientist Thales Melitus who lived in the sixth century BC Then, the Greeks called this stone the wondrous stone, and in the fourth century BC, the Chinese civilization knew the magnet , and mentioned it in the book of the Leader of the Valley of Demons, where the Chinese used it in maritime navigation in the Middle Ages.

The magnet among the Arabs

Al- Biruni's book Al-Jamahir fi Maarifat al-Jawahar came in a detailed explanation about magnets, and the common characteristics between it and amber. With it, the Chinese made ships from wooden panels made of olive wood; This is in order to avoid attracting these ships to the bottom of the waters of the China Sea; Where the magnetic stone is spread at its bottom.

Label the magnet

Two stories are suggested about the reason for the name of the magnet : The first belongs to a region in Asia Minor near Turkey and is called Magnesia. The magnetic stones were found in it for the first time, and the second time for a shepherd named Magnes. Notice the attraction of his metal stick to certain stones, and the attraction of the nails in his shoes strongly towards the black rocks, and these rocks were called magnetite; Relative to the shepherd who discovered it.

Types of magnets

The magnet is classified into three types, namely:

The permanent magnet: attractive fields are generated in this magnet without the need for any external source, force, or electric current. It is magnetic in nature, and the types of materials that make up a permanent magnet differ, and each type has unique characteristics and different attractive force than other types.
Temporary magnet: It is a non-magnetic substance that becomes like a magnet when affected by an external magnetic field, and it loses this property as soon as the influence of this field disappears.
Electromagnet : in this type, iron is transformed into a magnet. By wrapping it with a conductive and insulated wire, then the electric current is passed through this wire.

Magnet properties

Physicists have agreed on general terms and properties of magnets , including:

Magnetic field: It is also called magnetic field and magnetic induction, and it is the magnetic force that is generated in the field surrounding the magnet , and an experiment can be conducted to detect the magnetic field and its distribution, by placing a magnetic rod on a sheet, and scattering iron filings on it, and the frigidity is arranged in lines The circular field heading from north to south, while the internal magnetic field lines are opposite to the outer; As it turns from south towards north inside the magnet.
Magnetic: know magnetism that it is destined, and can find its value depending on the value of the magnetic moment.
Poles: A magnet, regardless of its length or size, consists of two poles: the north and south, and the two symbols (N, S) are noted at the ends of the magnetic bar. To denote the North , and the South, and the red color of the magnet usually indicates the North Pole, while the blue is the South Pole, and these poles are distinguished by that they attract in the event of differences; That is, the north pole of a magnet is attracted to the south pole of another magnet, but in the case of similar poles, they repel each other.
Horizontal movement: the magnet is characterized by its movement horizontally, heading towards the magnetic north when it is positioned freely; When suspended in the middle at its center of gravity, it will begin to move south and north, and will remain in motion until its axis is parallel to the Earth's magnetic meridian. Its poles in this case become magnetic north and south.
The attractive force of the magnet: The two ends of the magnet are the strongest compared to the rest of its parts. The magnet consists of the axis of the magnet, which is the line that connects the poles of the magnet, and this distance is called the effective length of the magnet, and it is symbolized by (2L), and the distance that separates the two ends of the magnet is called the natural length of the magnet, and the magnet is characterized by its weak power On the attraction, and is called the neutral zone.
The strength of the poles of a magnet is equal : the attractive forces of the magnetic north and south poles are equal; So that there is no difference between them at all.

The uses of the magnet

Magnets have many uses in modern industries, including the following:

Lifting heavy iron or steel weights, such as: landfills, scraps, and others.
Manufacture of electric motors, electric bells, dynamos , solenoids, and particle accelerators.
Fixation of magnetic train structures: This is one of the tremendous applications in physics. As the electric current and magnet are the main drivers of it; It depends on materials with a high capacity to conduct an electric current; To control the train the operations of attraction and repulsion arising from the magnetic force, and these trains may reach speeds of up to 431 km / hour.
The medical field: where the magnetic resonance device is one of the most important magnetic devices used in medical fields, and it is one of the innovations that helped advance the vision of the internal organs of the body more than X-rays. To diagnose the patient's medical condition.
Electronic devices: Magnets are used in the manufacture of electrical amplifiers, microphones and video-readers.