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}}The tesla (symbol: T) is the unit of magnetic flux density (also called magnetic B-field strength) in the International System of Units (SI). One tesla is equal to one weber per square metre. The unit was announced during the General Conference on Weights and Measures in 1960 and is namedWEB,weblink Details of SI units, sizes.com, 2011-07-01, 2011-10-04, in honour of Serbian-American electrical and mechanical engineer Nikola Tesla, upon the proposal of the Slovenian electrical engineer France Avčin.

Definition

A particle, carrying a charge of one coulomb (C), and moving perpendicularly through a magnetic field of one tesla, at a speed of one metre per second (m/s), experiences a force with magnitude one newton (N), according to the Lorentz force law. That is, mathrm{T = dfrac{N{cdot}s}{C{cdot}m}}.As an SI derived unit, the tesla can also be expressed in terms of other units. For example, a magnetic flux of 1 weber (Wb) through a surface of one square meter is equal to a magnetic flux density of 1 tesla.The International System of Units (SI), 8th edition, BIPM, eds. (2006), {{ISBN|92-822-2213-6}}, Table 3. Coherent derived units in the SI with special names and symbols {{webarchive|url=https://web.archive.org/web/20070618123613weblink |date=2007-06-18 }} That is,mathrm{T = dfrac{Wb}{m^2}}.Expressed only in SI base units, 1 tesla is:mathrm{T = dfrac{kg}{A{cdot}s^2}},where A is ampere, kg is kilogram, and s is second.Additional equivalences result from the derivation of coulombs from amperes (A), mathrm{C = A {cdot} s}:mathrm{T = dfrac{N}{A{cdot}m}},the relationship between newtons and joules (J), mathrm{J = N {cdot} m}:mathrm{T = dfrac{J}{A{cdot}m^2}},and the derivation of the weber from volts (V), mathrm{Wb = V {cdot} s}:mathrm{T = dfrac{V{cdot}{s}}{m^2}}.{{SI unit lowercase|Nikola Tesla|tesla|T}}

Electric vs. magnetic field

In the production of the Lorentz force, the difference between electric fields and magnetic fields is that a force from a magnetic field on a charged particle is generally due to the charged particle's movement,BOOK, Gregory, Frederick, 2003, History of Science 1700 to Present, The Teaching Company, while the force imparted by an electric field on a charged particle is not due to the charged particle's movement. This may be appreciated by looking at the units for each. The unit of electric field in the MKS system of units is newtons per coulomb, N/C, while the magnetic field (in teslas) can be written as N/(Câ‹…m/s). The dividing factor between the two types of field is metres per second (m/s), which is velocity. This relationship immediately highlights the fact that whether a static electromagnetic field is seen as purely magnetic, or purely electric, or some combination of these, is dependent upon one's reference frame (that is, one's velocity relative to the field).BOOK, Parker, Eugene, 2007, Conversations on electric and magnetic fields in the cosmos, Princeton University press, 65,weblink 978-0691128412, BOOK, Kurt, Oughstun, 2006, Electromagnetic and optical pulse propagation, Springer, 81,weblink 9780387345994, In ferromagnets, the movement creating the magnetic field is the electron spinBOOK, Herman, Stephen, 2003, Delmar's standard textbook of electricity, Delmar Publishers, 97,weblink 978-1401825652, (and to a lesser extent electron orbital angular momentum). In a current-carrying wire (electromagnets) the movement is due to electrons moving through the wire (whether the wire is straight or circular).

Conversion to non-SI units

One tesla is equivalent to:McGraw Hill Encyclopaedia of Physics (2nd Edition), C.B. Parker, 1994, {{ISBN|0-07-051400-3}}{{pn|date=June 2017}}{{plainlist|indent=1|1=

• 10,000 (or 104) G (gauss), used in the CGS system. Thus, 1 G = 10−4 T = 100 μT (microtesla).
• 1,000,000,000 (or 109) Î³ (gamma), used in geophysics.WEB,weblink gamma definition, Oxford Reference, 2 January 2024,

}}For the relation to the units of the magnetising field (ampere per metre or Oersted), see the article on permeability.

Examples

The following examples are listed in the ascending order of the magnetic-field strength.

• {{val|3.2e-5|u=T}} (31.869 Î¼T) – strength of Earth's magnetic field at 0° latitude, 0° longitude
• {{val|4e-5|u=T}} (40 Î¼T) – walking under a high-voltage power lineWEB, EMF: 7. Extremely low frequency fields like those from power lines and household appliances,weblinkweblink 2021-02-24, 2022-05-13, ec.europa.eu,
• {{val|5e-3|u=T}} (5 mT) – the strength of a typical refrigerator magnet
• 0.3 T – the strength of solar sunspots
• 1 T to 2.4 T – coil gap of a typical loudspeaker magnet
• 1.5 T to 3 T – strength of medical magnetic resonance imaging systems in practice, experimentally up to 17 TWEB,weblink Ultra-High Field, Bruker BioSpin, 4 October 2011, 21 July 2012,weblink" title="archive.today/20120721045726weblink">weblink dead,
• 4 T – strength of the superconducting magnet built around the CMS detector at CERNWEB, Superconducting Magnet in CMS,weblink 9 February 2013,
• 5.16 T – the strength of a specially designed room temperature Halbach arrayWEB, The Strongest Permanent Dipole Magnet,weblink 2 May 2020,
• 8 T – the strength of LHC magnets
• 11.75 T – the strength of INUMAC magnets, largest MRI scannerWEB, ISEULT – INUMAC,weblink 17 February 2014,
• 13 T – strength of the superconducting ITER magnet systemWEB,weblink ITER – the way to new energy, 19 April 2012,
• 14.5 T – highest magnetic field strength ever recorded for an accelerator steering magnet at FermilabWEB,weblink Fermilab achieves 14.5-tesla field for accelerator magnet, setting new world record, Hesla, Leah, 13 July 2020, 13 July 2020,
• 16 T – magnetic field strength required to levitate a frogJOURNAL, Of Flying Frogs and Levitrons" by M. V. Berry and A. K. Geim, European Journal of Physics, v. 18, 1997, p. 307–13, 1997, 10.1088/0143-0807/18/4/012, 1499061,weblinkweblink dead, 8 October 2020, 4 October 2020, Berry, M. V., Geim, A. K., European Journal of Physics, 18, 4, 307–313, (by diamagnetic levitation of the water in its body tissues) according to the 2000 Ig Nobel Prize in PhysicsWEB, The 2000 Ig Nobel Prize Winners, August 2006,weblink 12 May 2013, )
• 17.6 T – strongest field trapped in a superconductor in a lab as of July 2014WEB,weblink Superconductor Traps The Strongest Magnetic Field Yet, 2 July 2014, 2 July 2014,
• 20 T - strength of the large scale high temperature superconducting magnet developed by MIT and Commonwealth Fusion Systems to be used in fusion reactorsNEEDED, March 2024,
• 27 T – maximal field strengths of superconducting electromagnets at cryogenic temperatures
• 35.4 T – the current (2009) world record for a superconducting electromagnet in a background magnetic fieldWEB

• 45 T – the current (2015) world record for continuous field magnets
• 97.4 T – strongest magnetic field produced by a "non-destructive" magnetNEWS, World record pulsed magnetic field, Physics World,weblink 31 August 2011, 26 January 2022, )
• 100 T – approximate magnetic field strength of a typical white dwarf star
• 1200 T – the field, lasting for about 100 microseconds, formed using the electromagnetic flux-compression techniqueD. Nakamura, A. Ikeda, H. Sawabe, Y. H. Matsuda, and S. Takeyama (2018), Magnetic field milestone
• 109 T – Schwinger limit above which the electromagnetic field itself is expected to become nonlinear
• 108 – 1011 T (100 MT – 100 GT) – magnetic strength range of magnetar neutron stars

Notes and references

{{Reflist|2}}

External links

{{Wiktionary|tesla}}

• Gauss ↔ Tesla Conversion Tool

{{SI units|state=expanded}}{{Nikola Tesla}}