magnetic field

American  

noun

1. a region of space near a magnet, electric current, or moving charged particle in which a magnetic force acts on any other magnet, electric current, or moving charged particle.

2. magnetic intensity.

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magnetic field British  

noun

1. a field of force surrounding a permanent magnet or a moving charged particle, in which another permanent magnet or moving charge experiences a force Compare electric field

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magnetic field Scientific  

1. A field of force associated with changing electric fields, as when electric charges are in motion. Magnetic fields exert deflective forces on moving electric charges. Most magnets have magnetic fields as a result of the spinning motion of the electrons orbiting the atoms of which they are composed; electromagnets create such fields from electric current moving through coils. Large objects, such as the earth, other planets, and stars, also produce magnetic fields.

2. See Note at magnetism

3. See magnetic field strength

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magnetic field Cultural  

1. A magnetic field is said to exist in a region if a force can be exerted on a magnet. If a compass needle is deflected when it is put at a particular location, we say a magnetic field exists at that point, and the strength of the field is measured by the strength of the force of the compass needle. The Earth, the sun, and the Milky Way galaxy all have magnetic fields. All known magnetic fields are caused by the movement of electrical charges. Electrons in orbit in atoms give rise to magnetic fields, so that every atom is, like the Earth, surrounded by a magnetic field. (See magnet and magnetism.)

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Etymology

Origin of magnetic field

First recorded in 1835–45

Example Sentences

The quantum Hall effect occurs when electricity flows through extremely thin materials exposed to a magnetic field.

From Science Daily • Jun. 19, 2026

In this case, the more massive brown dwarf likely lost more of its original spin because of its stronger magnetic field.

From Science Daily • Jun. 13, 2026

Using this approach, phonons become synchronized when light or a magnetic field is applied from one direction, but synchronization does not occur when the same influence comes from the opposite direction.

From Science Daily • Jun. 12, 2026

The magnetosphere is the vast region of space shaped by the planet's magnetic field.

From Science Daily • May 29, 2026

We know that Earth’s magnetic field changes in power from time to time: during the age of the dinosaurs, it was up to three times as strong as now.

From "A Short History of Nearly Everything" by Bill Bryson