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 work, led by Cal Poly Physics Department Lecturer Ian Powell, focused on how varying a magnetic field over time can cause matter to exhibit unusual and previously unseen properties.

From Science Daily • May 4, 2026

"Spatially variable birefringence, that is, the difference in the propagation of different polarizations of light, acts like a synthetic magnetic field," explains Dr. Piotr Kapuściński of the Faculty of Physics at the University of Warsaw.

From Science Daily • Apr. 25, 2026

The results matched the experimental data closely, especially the unusual way superconductivity changes with the direction of the magnetic field.

From Science Daily • Apr. 10, 2026

The beams heat the plasma and spin it to create a stable magnetic field.

From The Wall Street Journal • Mar. 28, 2026

Gow was swept into Lawrence’s magnetic field and held there by the boss’s “sense of urgency, his willingness to try ideas rapidly and drop them when a better idea came along.”

From "Big Science" by Michael Hiltzik