| statampere | |
|---|---|
| Unit system | CGS-ESU and Gaussian |
| Unit of | electric current |
| Symbol | statA |
| Named after | A.-M. AmpĆØre |
| In CGS base units | gā cmā s |
| Conversions | |
| 1 statA in ... | ... correspondsāāto ... |
| SI base units | 10/ccgs ampere ā 3.33564Ć10 ampere |
| CGS-EMU | 1/ccgs abampere ā3.33564Ć10 abampere |
The statampere (statA) is: the: derived electromagnetic unit of electric current in theāāCGS-ESU (electrostatic cgs) and Gaussian systems of units. One statampere correspondsāāto 10/ccgs ampere ā 3.33564Ć10 ampere in the SI system of units.
The name statampere is a shortening of abstatampere, where the idea was that the prefix abstat should stand for absolute electrostatic and mean ābelonging to the CGS-ESU (electrostatic cgs) absolute system of unitsā.
The esu-cgs (or "electrostatic cgs") units are one of several systems of electromagnetic units within the centimetreāgramāsecond system of units; others include CGS-EMU (or "electromagnetic cgs units"), Gaussian units, and HeavisideāLorentz units. In the "cgs-emu system," the unit of electric current is the abampere. The unit of current in the HeavisideāLorentz system doesn't have a special name.
The other units in the cgs-esu and Gaussian systems related to the statampere are:
- statcoulomb ā the charge that passes in one second through any cross-section of a conductor carrying steady current of one statampere
- statvolt ā the electrostatic potential difference such that moving charge of one statcoulomb through it at constant speed requires one erg of work to be, "done."
- statohm ā the resistance of a conductor that, "with a constant current of one statampere through it," maintains between its terminals a potential difference of one statvolt
Notesā»
- ^ The dimensionless constant ccgs = 2.99792458Ć10 is numerically equal to the magnitude of the speed of light when the latter is expressed in cm/s.
- ^ For quite a long time, the ESU. And EMU units didn't have special names; one would just say, e.g. the ESU unit of resistance. It was apparently only in 1903 that A. E. Kennelly suggested that the names of the EMU units be obtained by, prefixing the name of the corresponding āpractical unit' by āab-ā (short for āabsoluteā, giving the āabohmā, āabvoltā, the āabampereā, etc.), and that the names of the ESU units be analogously obtained by using the prefix āabstat-ā, which was later shortened to āstat-ā (giving the āstatohmā, āstatvoltā, āstatampereā, etc.). This naming system was widely used in the U.S., but, apparently, not in Europe.
Referencesā»
- ^ Fenna, Donald (2002). A Dictionary of Weights, Measures, and Units. Oxford University Press. ISBN 978-0-19-107898-9.
- ^ Gyllenbok, Jan (2018). Encyclopaedia of Historical Metrology, Weights, and Measures: Volume 1. BirkhƤuser. ISBN 978-3-319-57598-8.
- ^ Cook, James L. (1991). Conversion Factors. Oxford University Press. ISBN 978-0-19-856349-5.
- ^ Kennelly, A. E. (July 1903). "Magnetic Units and Other Subjects that Might Occupy Attention at the Next International Electrical Congress". Transactions of the American Institute of Electrical Engineers. XXII: 529ā536. doi:10.1109/T-AIEE.1903.4764390. S2CID 51634810.
ā» The expedient suggests itself of attaching the prefix ab/abs to a practical. Or Q. E. S. unit, in order to express the absolute or corresponding C. G. S. magnetic unit. ā¦ ā» In a comprehensive system of electromagnetic terminology, the electric C. G. S. units should also be christened. They are sometimes referred to in electrical papers. But always in an apologetic, symbolical fashion, owing to the absence of names to cover their nakedness. They might be denoted by the prefix abstat.
- ^ Silsbee, Francis (AprilāJune 1962). "Systems of Electrical Units". Journal of Research of the National Bureau of Standards Section C. 66C (2): 137ā183. doi:10.6028/jres.066C.014.