Gauss (unit)

In physics, gauss (symbol G) is the unit of strength of magnetic flux density B (also known as magnetic induction). The unit is named in honor of the German mathematician and physicist Carl Friedrich Gauss.

One gauss is one maxwell/cm², where maxwell (symbol Mx) is the Gaussian unit for the magnetic flux Φ. The gauss belongs to the gaussian system of electromagnetic units, which is a cgs (centimeter-gram-second) system; this is why the unit of surface is cm².

The gauss is defined through an electromotive force $\scriptstyle {\mathcal {E}}$. For constant surface S and uniform rate of decrease of |B|, Faraday's law takes the simple form

$S|\mathbf {B} |=\Phi =-t\,{\mathcal {E}}.$

If S is in cm², t in s, and $\scriptstyle {\mathcal {E}}$ in abV ( = 10⁻⁸ volt) then |B| is in G and Φ is in Mx.

Related units

• The tesla (T) is the corresponding SI unit for B. 1 T corresponds to 10 000 G.
• The oersted is the Gaussian unit of strength of a magnetic field H. Note that the oersted is defined by means of an electric current that gives H.