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

On sunny days, however, they successfully returned, likely relying on the sun as a navigational cue instead of Earth's magnetic field.

From Science Daily • May 31, 2026

Fluid flow problems can often be simplified into two dimensions, but magnetic field generation must be solved in full 3D space, making the calculations far more difficult.

From Science Daily • May 26, 2026

Many aspects of the simulations were based on values already measured through other observations, including magnetic field strength and the size of emission regions around the black holes.

From Science Daily • May 24, 2026

Their work introduces a major new dataset that astronomers around the world will be able to use, along with a new model explaining how the Milky Way's magnetic field may have changed over time.

From Science Daily • May 20, 2026

With no magnetic field, Mars has no defense against harsh solar radiation.

From "The Martian" by Andy Weir