Gauss (unit)

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This article refers to the unit gauss; for other meanings see Gauss (disambiguation).

The gauss, abbreviated as G, is the cgs unit of magnetic flux density in a magnetic field (B), named after the German mathematician and physicist Carl Friedrich Gauss. One gauss is defined as one maxwell per square centimetre.

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[edit] Unit name and convention

This unit is named after Carl Friedrich Gauss. As with all units whose names are derived from the proper name of a person, the first letter of its symbol is uppercase ("G"). But when the unit is spelled out, it should always be written in lowercase ("gauss"), unless it begins a sentence.

[edit] Units conversions

According to the alternative cgs (centimeter-gram-second) system, the gauss is the unit of magnetic flux density (B), whilst the oersted is the unit of magnetic field intensity (H). One tesla is equal to 104 gauss, and one ampere per meter is equal to 4π10-3 oersted [1].

The units for magnetic flux (Φ)—which is the product of magnetic flux density (B) and area (A), i.e., Φ = BA—are the weber (Wb) in the MKS system and the maxwell (Mx) in the CGS system. The conversion factor is 108, since flux is the product of flux density and area, area having the units of the square of distance, thus 104 (flux density conversion factor) times the square of 102 (linear distance conversion factor, i.e., centimeters per meter).

[edit] Typical values

The earth's magnetic field is 0.5 gauss, a small iron magnet is about 100 gauss, a small Neodymium-iron-boron (NIB) magnet is about 2,000 gauss, a big electromagnet is about 15,000 gauss and the surface of a neutron star is about 1012 gauss[2].

[edit] References

  1. ^ Hayt, Jr., William H. (1974). Engineering Electromagnetics, Third Edition. McGraw-Hill. ISBN 0-07-027390-1
  2. ^ How strong are magnets?. Experiments with magnets and our surroundings. Magcraft. Retrieved on 2007-12-14.