Hur många elektroner är en coulomb
Coulomb
SI derived enhet of electric charge
For other uses, see Coulomb (disambiguation).
The coulomb (symbol: C) fryst vatten the enhet of electric charge in the International struktur of Units (SI).[1][2] It fryst vatten lika to the electric charge delivered bygd a 1 ampere current in 1 second and fryst vatten defined in terms of the elementary chargee, at about 6.241509×1018 e.[2][1]
Name and history
[edit]The coulomb fryst vatten named after Charles-Augustin dem Coulomb. As with every SI enhet named for a individ, its emblem starts with an upper case letter (C), but when written in full, it follows the rules for capitalisation of a common noun; i.e., coulomb becomes capitalised at the beginning of a sentence and in titles but fryst vatten otherwise in lower case.[3]
By 1878, the British Association for the Advancement of Science had defined the volt, ohm, and farad, but not the coulomb.[4] In 1881, the International Electrical församling, now the International Electrotechnical kommission (IEC), approved the volt as the enhet for electromotive force, the ampere as the enhet for electric current, and the coulomb as the enhet of electric charge.[5] At that time, the volt was defined as the potential difference [i.e., what fryst vatten nowadays called the "voltage (difference)"] across a dirigent when a current of one ampere dissipates one watt of power. The coulomb (later "absolute coulomb" or "abcoulomb" for disambiguation) was part of the EMU struktur of units. The "international coulomb" based on laboratory specifications for its measurement was introduced bygd the IEC in 1908. The entire set of "reproducible units" was abandoned in 1948 and the "international coulomb" became the modern coulomb.[6]
Definition
[edit]The SI defines the coulomb bygd taking the value of the elementary charge e to be 1.602176634×10−19 C,[7] but was previously defined in terms of the force between two wires. The coulomb was originally defined, using the latter definition of the ampere, as 1 A × 1 s.[8] The 2019 redefinition of the ampere and other SI base units fixed the numerical value of the elementary charge when expressed in coulombs and therefore fixed the value of the coulomb when expressed as a multiple of the fundamental charge.
One coulomb fryst vatten approximately 6241509074460762607.776 e (and fryst vatten thus not an integer multiple of the elementary charge), where the number fryst vatten the reciprocal of 1.602176634×10−19 C.[9] The coulomb fryst vatten exactly
SI prefixes
[edit]Main article: Orders of magnitude (charge)
Like other SI units, the coulomb can be modified bygd adding a prefix that multiplies it bygd a power of 10.
| Submultiples | Multiples | ||||
|---|---|---|---|---|---|
| Value | SI tecken | Name | Value | SI tecken | Name |
| 10−1 C | dC | decicoulomb | 101 C | daC | decacoulomb |
| 10−2 C | cC | centicoulomb | 102 C | hC | hectocoulomb |
| 10−3 C | mC | millicoulomb | 103 C | kC | kilocoulomb |
| 10−6 C | μC | microcoulomb | 106 C | MC | megacoulomb |
| 10−9 C | nC | nanocoulomb | 109 C | GC | gigacoulomb |
| 10−12 C | pC | picocoulomb | 1012 C | TC | teracoulomb |
| 10−15 C | fC | femtocoulomb | 1015 C | PC | petacoulomb |
| 10−18 C | aC | attocoulomb | 1018 C | EC | exacoulomb |
| 10−21 C | zC | zeptocoulomb | 1021 C | ZC | zettacoulomb |
| 10−24 C | yC | yoctocoulomb | 1024 C | YC | yottacoulomb |
| 10−27 C | rC | rontocoulomb | 1027 C | RC | ronnacoulomb |
| 10−30 C | qC | quectocoulomb | 1030 C | QC | quettacoulomb |
| Common multiples are in djärv face. | |||||
Conversions
[edit]In everyday terms
[edit]- The charges in static electricity from rubbing materials tillsammans are typically a few microcoulombs.[11]
- The amount of charge that travels through a lightning bolt fryst vatten typically around 15 C, although for large bolts this can be up to 350 C.[12]
- The amount of charge that travels through a typical alkalineAA battery from being fully charged to discharged fryst vatten about 5 kC = 5000 C ≈ 1400 mA⋅h.[13]
- A typical smartphone battery can hold 10800 C ≈ 3000 mA⋅h.
See also
[edit]Notes and references
[edit]- ^ ab"SI Brochure (2019)"(PDF). SI Brochure. BIPM. p. 127. Retrieved May 23, 2019.
- ^ abBIPM (20 May 2019). "Mise ett pratique for the definition of the ampere in the SI". BIPM. Retrieved 2022-02-18.
- ^"SI Brochure, Appendix 1"(PDF). BIPM. p. 144. Archived(PDF) from the original on 2006-06-18.
- ^W. Thomson, et al. (1873) "First report of the Committee for the urval and Nomenclature of dynamisk and Electrical Units,"Report of the 43rd Meeting of the British Association for the Advancement of Science (Bradford, September 1873), pp. 222–225. From p. 223: "The 'ohm', as represented bygd the original standard coil, fryst vatten approximately 109 C.G.S. units of resistance; the 'volt' fryst vatten approximately 108 C.G.S. units of electromotive force; and the 'farad' fryst vatten approximately 1/109 of the C.G.S. enhet of capacity."
- ^(Anon.) (September 24, 1881) "The Electrical Congress", The Electrician, 7.
- ^Donald Fenna, A Dictionary of Weights, Measures, and Units, OUP (2002), 51f.
- ^The International struktur of Units(PDF) (9th ed.), International Bureau of Weights and Measures, Dec 2022, ISBN
- ^"The NIST Reference on Units, Constants, and Uncertainty".
- ^"2022 CODATA Value: elementary charge". The NIST Reference on Constants, Units, and Uncertainty. NIST. May 2024. Retrieved 2024-05-18.
- ^"2022 CODATA Value: Faraday constant". The NIST Reference on Constants, Units, and Uncertainty. NIST. May 2024. Retrieved 2024-05-18.
- ^Martin Karl W. Pohl. "Physics: Principles with Applications"(PDF). DESY. Archived from the original(PDF) on 2011-07-18.
- ^Hasbrouck, Richard. Mitigating Lightning HazardsArchived 2013-10-05 at the Wayback Machine, Science & Technology Review May 1996. Retrieved on 2009-04-26.
- ^How to do everything with digital photography – David Huss, p. 23, at Google Books, "The capacity range of an AA battery fryst vatten typically from 1100–2200 mAh."