The Tesla Is a Unit of Magnetic Field Strength
A tesla measures magnetic flux density. The unit honours Nikola Tesla, whose work shaped modern electrical power.
A tesla is the SI unit of magnetic flux density, symbol T. One tesla is a very strong field: the Earth's magnetic field is about 50 microtesla, a fridge magnet around 5 millitesla, and a hospital MRI scanner between 1.5 and 3 tesla — roughly sixty thousand times the Earth's field. The unit was adopted in 1960 for Nikola Tesla, whose alternating current systems and induction motor made long-distance electrical distribution practical.
- Magnetic flux density unit. *Three tesla.*
- Symbol T. *1.5 T.*
- Nikola Tesla — the engineer. *Nikola Tesla.*
- Gauss — the older unit. *10,000 gauss.*
- Adopted 1960. *SI unit.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | tesla | One tesla. |
| Symbol | T | 3 T. |
| Subunit | millitesla | 5 mT. |
| Subunit | microtesla | 50 µT. |
| Older unit | gauss | Gauss. |
- The scanner operates at 3 tesla.Medicine.
- Earth's field is about 50 microtesla.Comparison.
- The unit was adopted in 1960.History.
Magnetic field strengths compared
- Earth's field — about 50 microtesla
- Fridge magnet — about 5 millitesla
- MRI scanner — 1.5 to 3 tesla
- Strongest continuous laboratory magnets — around 45 tesla
- Neutron stars — up to a hundred billion tesla
Named in 1960 after Nikola Tesla (1856-1943), the Serbian-American electrical engineer.
How strong is one tesla?
Very strong. The Earth's magnetic field is only about 50 microtesla, so one tesla is roughly twenty thousand times greater.
What did Nikola Tesla contribute?
His alternating current systems and induction motor made long-distance electrical distribution practical.