Magnetic field

Electromagnetism
Electricity · Magnetism · Magnetic permeability
Electrostatics Electric charge • Coulomb's law • Electric field • Electric flux • Gauss's law • Electric potential energy • Electric potential • Electrostatic induction • Electric dipole moment • Polarization density
Magnetostatics Ampère's law • Electric current • Magnetic field • Magnetization • Magnetic flux • Biot–Savart law • Magnetic dipole moment • Gauss's law for magnetism
Electrodynamics Lorentz force law • emf • Electromagnetic induction • Faraday’s law • Lenz's law • Displacement current • Maxwell's equations • EM field • Electromagnetic radiation • Liénard–Wiechert potential • Maxwell tensor • Eddy current
Electrical Network Electrical conduction • Electrical resistance • Capacitance • Inductance • Impedance • Resonant cavities • Waveguides
Covariant formulation Electromagnetic tensor • EM Stress-energy tensor • Four-current • Electromagnetic four-potential
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The magnetic field is the area around a magnet in which there is magnetic force. Moving electric charges can make magnetic fields. Magnetic fields can be illustrated by magnetic flux lines. At all times the direction of the magnetic field is shown by the direction of the magnetic flux lines. The strength of a magnet has to do with the spaces between the magnetic flux lines. The closer the flux lines are to each other, the stronger the magnet is. The farther away they are, the weaker. The flux lines can be seen by placing iron filings over a magnet. The iron filings move and arrange into the lines. Magnetic fields give power to other particles that are touching the magnetic field.

In physics, the magnetic field is a field that passes through space and which makes a magnetic force move electric charges and magnetic dipoles. Magnetic fields are around electric currents, magnetic dipoles, and changing electric fields.

When placed in a magnetic field, magnetic dipoles are in one line 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).

There are some notable kinds of magnetic field. For the physics of magnetic materials, see magnetism and magnet, and more specifically diamagnetism. For magnetic fields made by changing electric fields, see electromagnetism.

The electric field and the magnetic field are components of the electromagnetic field.

Research on magnetic fields began in 1269 when French scholar Petrus Peregrinus de Maricourt mapped out the magnetic field on the surface of a spherical magnet using iron needles. He said magnets always have both a north and south pole, no matter how finely one slices them. ^[1] The law of electromagnetism was developed by Michael Faraday.

1. ↑ Chapman, Allan (2007). "Peregrinus, Petrus (Flourished 1269)". Encyclopedia of Geomagnetism and Paleomagnetism. pp. 808–809. doi:10.1007/978-1-4020-4423-6_261. ISBN 978-1-4020-3992-8.