• ## Magnet - Wikipedia

OverviewNotesDiscovery and developmentPhysicsCommon usesMedical issues and safetyMagnetizing ferromagnetsDemagnetizing ferromagnets

1. ^ Platonis Opera Archived 2018-01-14 at the Wayback Machine, Meyer and Zeller, 1839, p. 989. 2. ^ The location of Magnesia is debated; it could be the region in mainland Greece or Magnesia ad Sipylum. See, for example, "Magnet". Language Hat blog. 28 May 2005. Archived from the original on 19 May 2012. Retrieved 22 March 2013.

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• ## Magnetism - Wikipedia

Magnetism is a class of physical phenomena that are mediated by magnetic fields. Electric currents and the magnetic moments of elementary particles give rise to a magnetic field, which acts on other currents and magnetic moments. The most familiar effects occur in ferromagnetic materials, which are strongly attracted by magnetic fields and can be magnetized to become permanent magnets ...

• ## Magnetism Encyclopedia

Earth's magnetism. The magnetic force present in an object seems to be located in two distinct regions of the objects known as poles. One pole is known as the north magnetic pole, while the other is known as the south magnetic pole. The magnetic force appears to flow out of one pole and into the other pole. The region of space through which the ...

• ## Magnetic declination - Wikipedia

Magnetic declination, or magnetic variation, is the angle on the horizontal plane between magnetic north (the direction the north end of a magnetized compass needle points, corresponding to the direction of the Earth's magnetic field lines) and true north (the direction along a meridian towards the geographic North Pole).This angle varies depending on position on the Earth's surface and ...

• ## Magnetic Levitation Encyclopedia

magnetic levitation or maglev (măg´lĕv), support and propulsion of objects or vehicles by the use of magnets. The magnets provide support without contact or friction, allowing for fast, quiet operation. In a typical system, the vehicle, which resembles a railroad car, travels above a guideway.

• ## Earth's magnetic field - Wikipedia

A magnetic field is a vector field, but if it is expressed in Cartesian components X, Y, Z, each component is the derivative of the same scalar function called the magnetic potential. Analyses of the Earth's magnetic field use a modified version of the usual spherical harmonics that differ by a

• ## Magnetic force physics - Encyclopedia Britannica

Magnetic force, attraction or repulsion that arises between electrically charged particles because of their motion. It is the basic force responsible for such effects as the action of electric motors and the attraction of magnets for iron. Electric forces exist among stationary electric charges; both electric and magnetic forces exist among moving electric charges.

• ## Magnet physics - Encyclopedia Britannica

Magnet, any material capable of attracting iron and producing a magnetic field outside itself. By the end of the 19th century all the known elements and many compounds had been tested for magnetism, and all were found to have some magnetic property. The most common was the property of diamagnetism,

• ## Magnetic resonance imaging - Wikipedia

Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body. MRI does not involve X-rays or the use of ionizing radiation, which distinguishes it from CT or CAT scans ...

• ICD-9-CM: 88.91
• ## Magnetic Lure Module - Bulbapedia, the community-driven ...

2019-05-17  Effect. The Magnetic Lure Module is a PokéStop module used to attract wild Pokémon to the PokéStop's location for 30 minutes, especially Electric-, Steel-, and Rock-type.PokéStops that have an active Magnetic Lure Module placed will have grey blocks of metal levitating upwards around them.

• ## Magnetism Encyclopedia

Earth's magnetism. The magnetic force present in an object seems to be located in two distinct regions of the objects known as poles. One pole is known as the north magnetic pole, while the other is known as the south magnetic pole. The magnetic force appears to flow out of one pole and into the other pole. The region of space through which the ...

• ## Confusion between B and H [Encyclopedia Magnetica]

A common imprecise short-hand is to refer to H as “magnetic field” instead of the full name “magnetic field strength” 19), but similarly for B, depending on the context. 20) However, in literature these terms are referred to by various names, and sometimes even with implied incorrect meaning.

• ## Electromagnetism physics - Encyclopedia Britannica

Electromagnetism, science of charge and of the forces and fields associated with charge. Electricity and magnetism are two aspects of electromagnetism. Electricity and magnetism were long thought to be separate forces. It was not until the 19th century that they were finally treated as interrelated

• ## Magnetism - Simple English Wikipedia, the free

Magnetic lines of force of a bar magnet shown by iron(Fe) filings on paper. A magnetized needle is floating in the air next to a metal ball. In physics, magnetism is a force that can attract (pull closer) or repel (push away) objects that have a magnetic material like iron inside them (magnetic objects).In simpler words, it is a property of certain substances which pull closer or repel other ...

• ## Magnetism Article about magnetism by The Free

Magnetic flaw detection and magnetic inspection techniques are also widely used. Magnetic materials are used to manufacture the magnetic circuits of generators, motors, transformers, relays, magnetic amplifiers, magnetic memory components, compass pointers, and magnetic tapes. History of the study of magnetism. The first written references to ...

• ## Flux fringing [Encyclopedia Magnetica]

Flux fringing is especially pertinent to magnetic cores with an air gap, for instance in flyback transformers or PFC inductors.The magnetic core is designed so that a well defined gap is placed in the magnetic circuit for storing energy in magnetic field.. An air gap constitutes a magnetic discontinuity in the magnetic core. Relative permeability of air gap is $\mu_{r,gap} \approx 1$ whereas ...

• ## The Magnetic Compass Encyclopedia

The Magnetic CompassOverviewThe magnetic compass was an important advance in navigation because it allowed mariners to determine their direction even if clouds obscured their usual astronomical cues such as the North Star. It uses a magnetic needle that can turn freely so that it always points to the north pole of the Earth's magnetic field.

• ## Magnetic force physics - Encyclopedia Britannica

The magnetic force influences only those charges that are already in motion. It is transmitted by the magnetic field. Both magnetic fields Encyclopædia Britannica, Inc. The magnetic force on a moving charge is exerted in a direction at a right angle to the plane formed by the direction of its

• ## Magnet - Simple English Wikipedia, the free encyclopedia

A magnet is a very special metal.When a magnet goes near a special kind of metal or other magnets, and the poles (sides) touching are opposite, it will pull, or attract the other metal or magnet closer. Also, if the two poles are the same, the two magnets will push away, or repel, from each other.This is called magnetism.Magnets can make some other metals into magnets when they are rubbed ...

• ## Hysteresis physics - Encyclopedia Britannica

Hysteresis, lagging of the magnetization of a ferromagnetic material, such as iron, behind variations of the magnetizing field. When ferromagnetic materials are placed within a coil of wire carrying an electric current, the magnetizing field, or magnetic field strength H, caused by the current forces some or all of the atomic magnets in the material to align with the field.

• ## Magnetism Article about magnetism by The Free

Magnetic flaw detection and magnetic inspection techniques are also widely used. Magnetic materials are used to manufacture the magnetic circuits of generators, motors, transformers, relays, magnetic amplifiers, magnetic memory components, compass pointers, and magnetic tapes. History of the study of magnetism. The first written references to ...

• ## Magnetic field strength [Encyclopedia Magnetica]

The quantitative measure of strongness or weakness of the magnetic field is given by magnetic field intensity or magnetic field strength. The magnetic field intensity at any point in the magnetic field is defined as the force experienced by a unit north pole of one weber strength, placed at that point.

• ## Magnet - Simple English Wikipedia, the free encyclopedia

A magnet is a very special metal.When a magnet goes near a special kind of metal or other magnets, and the poles (sides) touching are opposite, it will pull, or attract the other metal or magnet closer. Also, if the two poles are the same, the two magnets will push away, or repel, from each other.This is called magnetism.Magnets can make some other metals into magnets when they are rubbed ...

• ## Magnetism - Simple English Wikipedia, the free

Earth does change its magnetic poles every million years (plus or minus 200,000 years). Before a change of magnetic field, the Earth's magnetic field becomes weaker and moves around, like a spinning top would before it falls. The Earth has already had hundreds of changes (flip flops).

• ## Electromagnetic force - Energy Education

The electromagnetic force, also called the Lorentz force, explains how both moving and stationary charged particles interact. It's called the electromagnetic force because it includes the formerly distinct electric force and the magnetic force; magnetic forces and electric forces are really the same fundamental force. The electromagnetic force is one of the four fundamental forces.

• ## Flux fringing [Encyclopedia Magnetica]

Flux fringing is especially pertinent to magnetic cores with an air gap, for instance in flyback transformers or PFC inductors.The magnetic core is designed so that a well defined gap is placed in the magnetic circuit for storing energy in magnetic field.. An air gap constitutes a magnetic discontinuity in the magnetic core. Relative permeability of air gap is $\mu_{r,gap} \approx 1$ whereas ...

• ## DK Science Technology: Magnetism

Magnetism is an invisible force that attracts or repels some materials, such as iron and steel, but not others, like plastic and silver. In a magnetic material, the atoms line up in groups or regions called MAGNETIC DOMAINS. Every magnet has a north magnetic pole and a south magnetic pole. These are

• ## Compass Encyclopedia

An important feature found on many compasses is automatic declination adjustment. Declination, also known as variance, is the difference between magnetic North (the direction to which the needle points) and true North. This difference exists because Earth's magnetic field does not align exactly with its North and South poles. The amount of ...

• ## Magnetic reluctance - Simple English Wikipedia, the free ...

Magnetic reluctance, or magnetic resistance, is a measurement used in the analysis of magnetic circuits.It is like resistance in an electrical circuit, but rather than dissipating magnetic energy it stores magnetic energy.As an electric field causes an electric current to follow the path of least resistance, a magnetic field causes magnetic flux to follow the path of least magnetic reluctance.

• ## How Maglev Works Department of Energy

2016-06-14  Both loops use magnetic repulsion to keep the train car in the optimal spot; the further it gets from the center of the guideway or the closer to the bottom, the more magnetic resistance pushes it back on track. The third set of loops is a propulsion system run by alternating current power. Here, both magnetic attraction and repulsion are used ...