What is the unit of measure of magnetic field ?
Tesla
Magnetic field is measured in tesla — option 4.
The definition. One tesla is the magnetic flux density that exerts a force of one newton on a conductor one metre long carrying one ampere at right angles to the field :
\(1\ \text{T}=1\ \dfrac{\text{N}}{\text{A}\cdot\text{m}}=1\ \dfrac{\text{Wb}}{\text{m}^{2}}\)
The unit is named after Nikola Tesla.
| Option | What it actually is |
|---|---|
| Cobalt | A chemical element, and a ferromagnetic one — which is why it appears here — but not a unit of anything |
| Ampere | Unit of electric current |
| Ohm | Unit of electrical resistance |
| Tesla | Unit of magnetic flux density |
A sense of scale. The tesla is a very large unit :
| Source | Field strength |
|---|---|
| Earth’s magnetic field | 25 to 65 microtesla |
| Refrigerator magnet | About 5 millitesla |
| Hospital MRI scanner | 1·5 to 3 tesla |
| Strongest steady laboratory magnets | Around 45 tesla |
Related magnetic units. The older CGS unit is the gauss, equal to 10−4 tesla — so the Earth’s field is about half a gauss. Magnetic flux, as distinct from flux density, is measured in webers, and one weber per square metre is one tesla. Magnetic field strength H, a different quantity, is measured in ampere per metre.
Some other named units worth keeping straight : the volt for potential difference, the farad for capacitance, the henry for inductance, the coulomb for charge, the hertz for frequency, the newton for force and the joule for energy — each named for the scientist whose work defined the quantity.
Hence, the answer is Tesla.
Similar Questions
Which of the following is equivalent to tesla ?
Important Questions from Magnetism
What is the direction of magnetic field lines outside a magnet?
Which of the following statement is correct?
।. Magnetic field has both magnitude and direction.
II. The magnetic field inside a current-carrying straight long solenoid is the same at all points.
A freely suspended magnet always aligns in the ________direction.
The magnetic effect of electric current was discovered by _____.
The important property of magnet which was exploited by navigators and travelers from the ancient times is:
