This article is about objects and devices that produce magnetic fields. For a description of magnetic materials, see Magnetism. For other uses, see Magnet (disambiguation).
A magnetite rock is being pulled by a neodymium magnet on top.
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A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, cobalt, etc. and attracts or repels other magnets.
A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. An everyday example is a refrigerator magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include the elements iron, nickel and cobalt and their alloys, some alloys of rare-earth metals, and some naturally occurring minerals such as lodestone. Although ferromagnetic (and ferrimagnetic) materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic, all other substances respond weakly to a magnetic field, by one of several other types of magnetism.
Ferromagnetic materials can be divided into magnetically "soft" materials like annealed iron, which can be magnetized but do not tend to stay magnetized, and magnetically "hard" materials, which do. Permanent magnets are made from "hard" ferromagnetic materials such as alnico and ferrite that are subjected to special processing in a strong magnetic field during manufacture to align their internal microcrystalline structure, making them very hard to demagnetize. To demagnetize a saturated magnet, a certain magnetic field must be applied, and this threshold depends on coercivity of the respective material. "Hard" materials have high coercivity, whereas "soft" materials have low coercivity. The overall strength of a magnet is measured by its magnetic moment or, alternatively, the total magnetic flux it produces. The local strength of magnetism in a material is measured by its magnetization.
An electromagnet is made from a coil of wire that acts as a magnet when an electric current passes through it but stops being a magnet when the current stops. Often, the coil is wrapped around a core of "soft" ferromagnetic material such as mild steel, which greatly enhances the magnetic field produced by the coil.
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a...
Magnet is a URI scheme that defines the format of magnet links, a de facto standard for identifying files (URN) by their content, via cryptographic hash...
In the U.S. education system, magnet schools are public schools with specialized courses or curricula. Normally, a student will attend an elementary school...
A neodymium magnet (also known as NdFeB, NIB or Neo magnet) is a permanent magnet made from an alloy of neodymium, iron, and boron to form the Nd2Fe14B...
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. Electromagnets usually consist of wire wound into...
magnetfishers or magneteers. It is thought magnet fishing was initially started by boaters using magnets to recover fallen keys from the water. Magnet fishing...
permanent magnet motor is a type of electric motor that uses permanent magnets for the field excitation and a wound armature. The permanent magnets can either...
A superconducting magnet is an electromagnet made from coils of superconducting wire. They must be cooled to cryogenic temperatures during operation. In...
A horseshoe magnet is either a permanent magnet or an electromagnet made in the shape of a horseshoe (in other words, in a U-shape). The permanent kind...
A dipole magnet is the simplest type of magnet. It has two poles, one north and one south. Its magnetic field lines form simple closed loops which emerge...
A magnet motor or magnetic motor is a type of perpetual motion machine, which is intended to generate a rotation by means of permanent magnets in stator...
Molecular magnet can refer to: Molecule-based magnet, an unconventional magnetic material that consists of organic molecules, coordination compounds, or...
Monster Magnet is an American rock band, founded in Red Bank, New Jersey in 1989 by Dave Wyndorf (vocals and guitar), John McBain (guitar) and Tim Cronin...
An electropermanent magnet or EPM is a type of permanent magnet in which the external magnetic field can be switched on or off by a pulse of electric...
permanent magnets or electromagnets turns in step with the stator field at the same rate and as a result, provides the second synchronized rotating magnet field...
A refrigerator magnet or fridge magnet is a small magnet, often attached to an artistic or whimsical ornament, which may be used to post items such as...
poles of a permanent magnet to help preserve the strength of the magnet by completing the magnetic circuit; it is important for magnets that have low magnetic...
Project Magnet may refer to: Project Magnet (UFO), a Canadian unidentified flying object (UFO) study Project Magnet (USN), a U.S. Navy geomagnetic survey...
A plastic magnet is a non-metallic magnet made from an organic polymer. Plastic magnets could be used in computer hardware such as disc drives, as well...
Magnet is a British kitchen retailer operating in over two hundred locations across the United Kingdom supplying products under the Magnet and Magnet...
Magnets exert forces and torques on each other through the interaction of their magnetic fields. The forces of attraction and repulsion are a result of...
practice involving the weak static magnetic field produced by a permanent magnet which is placed on the body. It is similar to the alternative medicine practice...
: ch13 : 278 A permanent magnet's magnetic field pulls on ferromagnetic materials such as iron, and attracts or repels other magnets. In addition, a nonuniform...
The Magnet was a British weekly boys' story paper published by Amalgamated Press. It ran from 1908 to 1940, publishing a total of 1,683 issues. Each issue...
Quadrupole magnets, abbreviated as Q-magnets, consist of groups of four magnets laid out so that in the planar multipole expansion of the field, the dipole...
In physics, amorphous magnet refers to a magnet made from amorphous solids. Below a certain temperature, these magnets present permanent magnetic phases...
Freak Magnet is a studio album by Violent Femmes, released in 2000. It contains the single "Sleepwalkin'". Originally scheduled for a 1998 release on Interscope...
"Magnet and Steel" is a hit single written and performed by Walter Egan, released in March 1978. It was the first and biggest hit on Egan's second solo...
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