# Gauss (unit)

In physics, **gauss** (symbol **G**) is the unit of strength of magnetic flux density |**B**| (also known as magnetic induction). The gauss belongs to the Gaussian and emu (electromagnetic) systems of units, which are cgs (centimeter-gram-second) systems. The unit is related to the SI unit tesla (T) as follows.

- 1 G ≡ 1 Mx/cm
^{2}= 10^{−4}T,

where Mx (maxwell) is the Gaussian unit for magnetic flux.

The unit is named in honor of the German mathematician and physicist Carl Friedrich Gauss.

## Definition

The gauss is defined through an electromotive force induced by a change in magnetic field **B**. For constant surface *S* and uniform rate of decrease of |**B**|, Faraday's law takes the simple form

where Φ is the magnetic flux passing through *S* and uniform rate of decrease means linearity in time:
Hence, gauss is equal to maxwell per unit surface, where maxwell (symbol Mx) is the Gaussian unit for Φ, and |**B**| is a flux density.

In Gaussian units *S* is in cm^{2}, time *t* in s, in abV ( = 10^{−8} volt), |**B**| in G, and Φ in Mx:

- 1 G = 1 Mx/cm
^{2}= 1 abV•s/cm^{2}

## Related unit

- The oersted is the Gaussian unit of strength of a magnetic field |
**H**|. The oersted is defined by means of an electric current giving the field**H**.