ampere | has symbol A | ![2001-09-27 09:32:49.0 2001-09-27 09:32:49.0](facet.gif) |
has consequence fixes the magnetic constant (permeability of vacuum) at exactly 4 × 10-7 H · m-1 | ![2001-09-27 09:32:49.0 2001-09-27 09:32:49.0](facet.gif) |
has definition Unit of electric current. "The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 meter apart in vacuum, would produce between these conductors a force equal to 2 × 10-7 newton per meter of length" CIPM 1946, Resolution 2, approved by the 9th CGPM 1948). A current of 1 A is equivalent to the passage along the filament of a light bulb of about 6 × 1018 electronic charges per second. | ![has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:32:49.0 has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:32:49.0](facet.gif) |
has definition constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 meter apart in vacuum, would produce between these conductors a force equal to 2 × 10-7 newton per meter of length | ![2001-09-27 09:32:49.0 2001-09-27 09:32:49.0](facet.gif) |
is an instance of current unit | ![2001-09-27 09:32:49.0 2001-09-27 09:32:49.0](facet.gif) |
is an instance of base SI unit | ![2001-09-27 09:32:49.0 2001-09-27 09:32:49.0](facet.gif) |
current unit | is a unit of current | ![2001-09-27 09:32:49.0 2001-09-27 09:32:49.0](facet.gif) |
SI unit | is an acronym for Syteme Internationale | ![2001-09-27 09:32:55.0 2001-09-27 09:32:55.0](facet.gif) |
unit | has historical origin | ![2001-09-27 09:32:42.0 2001-09-27 09:32:42.0](facet.gif) |
represents | ![2001-09-27 09:32:42.0 2001-09-27 09:32:42.0](facet.gif) |