Magnetic field

area of influence of a magnet, magnetic power of a unit of a freight to a unit of speed

In physics, the magnetic field is a field that permeates space and which exerts a magnetic force on moving electric charges and magnetic dipoles. Magnetic fields surround electric currents, magnetic dipoles, and changing electric fields.When placed in a magnetic field, magnetic dipoles align their axes to be parallel with the field lines, as can be seen when iron filings are in the presence of a magnet. Magnetic fields also have their own energy and momentum, with an energy density proportional to the square of the field intensity. The magnetic field is measured in the units of teslas (SI units) or gauss (cgs units).
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Magnetic field The three-dimensional area surrounding a magnet, in which its force is active. During MRI, the patient's body is permeated by the [more]Magnetic field - Community and Resources

Noun
1. the lines of force surrounding a permanent magnet or a moving charged particle
(synonym) magnetic flux, flux
(hypernym) field, field of force, force field
(hyponym) magnetosphere

A region where a stationary magnet experiences a force. Magnetic lines of force are imaginary lines in space along which a hypothetical solitary magnetic north pole will travel. It has no effect on a static charged particle, if the magnetic field too is unchanging. It is a changing magnetic field that can accelerate charged particles. Field strength is measured in teslas and for comparison a good permanent magnet produces about 1 T, the magnetic field on the earth's surface is about 4 x 10-5 T, and interplanetary fields are around 5 x 10-9 T.