Tesla (unit)

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The tesla (symbol T) is the SI derived unit of magnetic flux density (which is also known as "magnetic field strength" and "magnetic induction"). (Commonly, the symbol B is used for magnetic flux density, but this is not necessarily true.) One tesla is equal to one weber per square meter, and it was defined in 1960^[1] in honor of the Serbian-American inventor, physicist, and electrical engineer Nikola Tesla. One billionth of a tesla is a nanotesla, equivalent to 0.01 mG or 0.01 milligauss, and it is in nanoteslas that common metric home measurements are made to determine local magnetic field levels.

Contents 1 Definition 2 Conversions 3 Examples 4 External links 5 References

[edit] Definition

This SI unit is named after Nikola Tesla. As with every SI unit whose name is derived from the proper name of a person, the first letter of its symbol is uppercase (T). When an SI unit is spelled out in English, it should always begin with a lowercase letter (tesla), except where any word would be capitalized, such as at the beginning of a sentence or in capitalized material such as a title. Note that "degree Celsius" conforms to this rule because the "d" is lowercase.

—Based on The International System of Units, section 5.2.

A particle passing through a magnetic field of 1 tesla at 1 meter per second carrying a charge of 1 Coulomb experiences a force of 1 Newton, according to the Lorentz Force Law. As an SI derived unit, the tesla can also be expressed as:

(In SI base units)

Units used:

• A = ampere
• C = coulomb
• kg = kilogram
• m = meter
• N = newton
• s = second
• T = tesla
• V = volt
• Wb = weber

[edit] Conversions

1 tesla is equivalent to:

• 10,000 (or 10⁴) gauss (G), used in the CGS system. Thus, 10 G = 1 mT (1 millitesla)
• 1,000,000,000 (or 10⁹) gammas (γ), used in geophysics. Thus, 1 γ = 1 nT (nanotesla)

For those concerned with low-frequency electromagnetic radiation in the home, the following conversions are needed most:

• 1000 nanotesla = 1 microtesla = 10 milligauss (mG)
• 1,000,000 microtesla = 1 tesla

For the relation to the units of the magnetizing field (amperes per metre or oersteds) see the article on permeability.

400 mT = 4000 G

[edit] Examples

• 31 µT (3.1×10⁻⁵ T) - strength of Earth's magnetic field at 0° latitude (on the equator)

[edit] External links

• Gauss<->Tesla Conversion Tool

[edit] References