Magnetic field

:For other senses of this term, see magnetic field (disambiguation).

Symbols and terminology

Magnetic field is usually denoted by the symbol mathbf{B} . Historically, mathbf{B} was called the magnetic flux density or the magnetic induction, and mathbf{H} = mathbf{B} / mu was called the magnetic field (or magnetic field strength), and this terminology is still often used to distinguish the two in the context of magnetic materials (non-trivial permeability μ). Otherwise, however, this distinction is often ignored, and both symbols are frequently referred to as the magnetic field. (Some authors call H the auxiliary field, instead.) In SI units, mathbf{B} and mathbf{H} are measured in teslas (T) and amperes per meter (A/m), respectively; or, in cgs units, in gauss (G) and oersteds (Oe), respectively.

Related Topics:
Magnetic flux density - Permeability - SI - Tesla - Ampere - Meter - Cgs - Gauss - Oersted

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Two parallel wires carrying an electric current in the same sense will generate a magnetic

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field which will cause a force of attraction to each other. This fact is used to generate the value of an ampere of electric current. Note that while like charges repel and unlike ones attract, the opposite holds for currents: if the current in one of the two parallel wires is reversed, the two will repel.

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