Science  People  Locations  Timeline
Index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Home > Coulomb


The coulomb, symbol C, is the SI unit of electric charge, and is defined in terms of the ampere: 1 coulomb is the amount of electric charge carried by a current of 1 ampere flowing for 1 second. It is also about 6.241506×1018 times the charge of an electron. It is named after Charles-Augustin de Coulomb ( 1736 - 1806).

1 A wrong definition

It is sometimes incorrectly said that a coulomb is defined as Avogadro's number of electrons; this is completely wrong. Just as the ampere and second were defined well before the electron's charge was known, the kilogram was defined well before the mass of the amu was known. Neither value has anything to do with the other.

2 SI electricity units

SI electricity units

[ }|action=edit}} Edit }]

SI Base unit
Name Symbol Quantity Notes
ampere A Current
SI Derived units
Name Symbol Quantity Notes
volt V Potential difference
ohm Ω Resistance, Impedance, Reactance
farad F Capacitance
henry H Inductance
siemens S Conductance, Admittance, Susceptance −1
coulomb C Electric charge
ohm · metre Ω · m Resistivity
siemens per metre S / m Conductivity
henry per metre H /m Permeability μ
farad per metre F / m Permittivity ε
reciprocal farad F−1 Elastance =F−1

3 See also


SI derived units Units of electrical charge




Read more »

Non User