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maxwell

The unit of magnetic flux in the centimeter-gram-second electromagnetic system of units. Symbol, Mx. The magnetic flux which, linking a circuit of 1 turn, produces in it an electromotive force of 1 abvolt as it is reduced to zero in 1 second. Sometimes called a line or abweber (symbol, abW). Its dimensions are (mass × square of length) over (current × square of time).

One maxwell corresponds to 10⁻⁸ weber in SI; they are not strictly comparable because cgs has three dimensions and SI (for mechanics and electric quantities) has four.

The maxwell was adopted by the Fifth International Electrical Congress held in Paris in 1900 (see the report in Nature). It was confirmed again when the Advisory Committee on Nomenclature of the International Electrotechnical Commission adopted the name maxwell for the unit of magnetic flux at its meeting in Stockholm in 1930.^1,2

engraving of Maxwell

The maxwell is named for the physicist James Clerk Maxwell (1831–1879).

According to the current national standard in the United States³, the maxwell is not to be used. The weber should be used instead.

1. Nature, volume 126, page 252, (1930).

2. International Electrotechnical Commission.
Recommendations in the field of quantities and units used in electricity. (1st ed.)
IEC Publication 164.
Geneva, 1964.

Page 27.

3. IEEE/ASTM SI 10™-2002.
American National Standard for Use of the International System of Units (SI): The Modern Metric System.
New York: IEEE, 30 December 2002.

See Section 3.3.3.