The
tesla (symbol
T) is the
SI derived unitSI derived units are part of the SI system of measurement units and are derived from the seven SI base units.Note that while the names of all SI units are in lowercase, the symbols of units named after people are written with an initial capital letter...
of
magnetic fieldMagnetic fields surround magnetic materials and electric currents and are detected by the force they exert on other magnetic materials and moving electric charges...
B (which is also known as "magnetic flux density" and "magnetic induction"). One tesla is equal to one
weberIn physics, the weber is the SI unit of magnetic flux. A flux density of one Wb/m2 is one tesla.It is named after the German physicist Wilhelm Eduard Weber .- Definition :...
per square meter, and it was defined in 1960 in honor of the Serbian-American
inventorAn inventor is a person who creates or discovers a new method, form, device or other useful means. The word inventor comes form the latin verb invenire, invent-, to find...
,
physicistA physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
, and electrical engineer
Nikola TeslaNikola Tesla was an inventor and a mechanical and electrical engineer. He is frequently cited as one of the most important contributors to the birth of commercial electricity and is best known for his many revolutionary developments in the field of electromagnetism in the late 19th and early 20th...
. One billionth of a tesla is a nanotesla, equivalent to 0.01 milli
gaussThe gauss, abbreviated as G, is the cgs unit of measurement of a magnetic field B , named after the German mathematician and physicist Carl Friedrich Gauss. One gauss is defined as one maxwell per square centimeter.-Unit name and convention:This unit is named after Carl Friedrich Gauss...
(mG) and it is in nanoteslas that common metric home measurements are made to determine local magnetic field levels. The strongest fluxes commonly encountered are from neodymium supermagnets which are usually between about 0.25 and 0.45 T.
Definition
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 unitSI derived units are part of the SI system of measurement units and are derived from the seven SI base units.Note that while the names of all SI units are in lowercase, the symbols of units named after people are written with an initial capital letter...
, the tesla can also be expressed as:
(In SI base unitThe International System of Units defines seven SI base units. for a set of physical quantities of measure, or dimensions, that are used to define all other SI units, known as SI derived units....
s)
Units used:
- A = ampere
The ampere is the SI unit of electric current. The ampere, in practice often shortened to amp, is an SI base unit, and is named after André-Marie Ampère, one of the main discoverers of electromagnetism....
- C = coulomb
The coulomb is the SI derived unit of electric charge. It is named after Charles-Augustin de Coulomb.- Definition :If 2 like point charges of equal magnitudes are placed in a vacuum at a distance of 1 metre away from each other and if they repel each other with a force of 9*1000000000 Newton, then...
- kg = kilogram
The kilogram is the base unit of mass in the International System of Units .[The spelling kilogram is the modern spelling used by the International Bureau of Weights and Measures , the U.S...]
- m = meter
- N = newton
- s = second
The second , sometimes abbreviated sec., is the name of a unit of time, and is the International System of Units base unit of time...
- T = tesla
- V = Volt
The volt is the SI derived unit of electromotive force, commonly called "voltage". It is also the unit for the related but slightly different quantity electric potential difference...
- Wb = weber
In physics, the weber is the SI unit of magnetic flux. A flux density of one Wb/m2 is one tesla.It is named after the German physicist Wilhelm Eduard Weber .- Definition :...
Conversions
1 tesla is equivalent to:
- 10,000 (or 104) gauss
The gauss, abbreviated as G, is the cgs unit of measurement of a magnetic field B , named after the German mathematician and physicist Carl Friedrich Gauss. One gauss is defined as one maxwell per square centimeter.-Unit name and convention:This unit is named after Carl Friedrich 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
Geophysics, a major discipline of the Earth sciences and a subdiscipline of physics, is the study of the whole Earth by the quantitative observation of its physical properties. Geophysical data are used in academics to observe tectonic plate motions, study the internal structure of the Earth,...
. 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 (
ampereThe ampere is the SI unit of electric current. The ampere, in practice often shortened to amp, is an SI base unit, and is named after André-Marie Ampère, one of the main discoverers of electromagnetism....
s per
metreThe metre or meter is the basic unit of length in the International System of Units . Historically, the metre was defined by the French Academy of Sciences as the length between two marks on a platinum-iridium bar, which was designed to represent one ten-millionth of the distance from the Equator...
or
oerstedOersted is the unit of magnetizing field in the CGS system of units.-History:...
s) see the article on
permeabilityIn electromagnetism, permeability is the degree of magnetization of a material that responds linearly to an applied magnetic field. Magnetic permeability is typically represented by the Greek letter μ. The term was coined in September, 1885 by Oliver Heaviside...
.
400 mT = 4000 G
Examples
- 31 µT (3.1×10−5 T) - strength of Earth's magnetic field at 0° latitude (on the equator)
External links