coulomb(redirected from Exacoulomb)
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coulomb(ko͞o`lŏm) [for C. A. de CoulombCoulomb, Charles Augustin de
, 1736–1806, French physicist. In 1789 he retired from his posts as military engineer and as superintendent of waters and fountains and devoted himself to continuing his scientific research.
..... Click the link for more information. ], abbr. coul or C, unit of electric chargecharge,
property of matter that gives rise to all electrical phenomena (see electricity). The basic unit of charge, usually denoted by e, is that on the proton or the electron; that on the proton is designated as positive (+e
..... Click the link for more information. . The absolute coulomb, the current U.S. legal standard, is the amount of charge transferred in 1 second by a current of 1 ampereampere
, abbr. amp or A, basic unit of electric current. It is the fundamental electrical unit used with the mks system of units of the metric system. The ampere is officially defined as the current in a pair of equally long, parallel, straight wires 1 meter apart that produces
..... Click the link for more information. ; i.e., it is 1 ampere-second.
(1) A unit of the quantity of electricity (electric charge) in the International System of Units (SI). It was named in honor of the French physicist C. Coulomb. The abbreviations are k in Russian and C in the international system. One coulomb is the charge carried through the cross section of a conductor in 1 sec by a current of 1 ampere. The relationships between the coulomb and the units of charge in the cgs system of units are as follows: 1 C = 3 X 109 units of the cgs electrostatic (cgs esu) system; 1 C = 0.1 unit of the cgs electromagnetic (cgs emu) system.
(2) The unit of flux of electric displacement (the flux of electric induction) in the SI system of units: 1 C is the electric flux through a closed surface that contains a free charge of 1 C. The relationships between the coulomb and the unit of electric flux in the cgs system of units are as follows: 1 C ≃ 4π X 3 X 109 units of the cgs esu system; 1 C = 0.4π units of the cgs emu system.