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Official Aftermovie @ Telekom VOLT Fesztivál 2017
Official Aftermovie @ Telekom VOLT Fesztivál 2017
Published: 2017/11/16
Channel: VOLT Fesztivál
2017 Chevy Volt or Tesla Model 3?  Review of Volt.
2017 Chevy Volt or Tesla Model 3? Review of Volt.
Published: 2016/05/29
Channel: The 8-Bit Guy
2017 Chevy Volt - Review and Road Test
2017 Chevy Volt - Review and Road Test
Published: 2015/12/07
Channel: Kelley Blue Book
Yung Lean - Volt
Yung Lean - Volt
Published: 2014/11/13
Channel: Yung Lean
4 Things You Will Hate About The Chevy Volt!
4 Things You Will Hate About The Chevy Volt!
Published: 2015/09/13
Channel: Vehicle Virgins
Chevrolet Volt - El eléctrico cercano a lo ideal
Chevrolet Volt - El eléctrico cercano a lo ideal
Published: 2016/09/09
Channel: AutoDinámico
Punnany Massif feat. Pásztor Anna, Charlie, Pető Szabolcs(prod. Rendben Man): Ami VOLT az majd lesz!
Punnany Massif feat. Pásztor Anna, Charlie, Pető Szabolcs(prod. Rendben Man): Ami VOLT az majd lesz!
Published: 2017/06/07
Channel: VOLT Fesztivál
CHEVROLET VOLT - ESPECIAL #71 | ACELERADOS
CHEVROLET VOLT - ESPECIAL #71 | ACELERADOS
Published: 2016/06/30
Channel: Acelerados
Warframe戰甲神兵-Volt Prime
Warframe戰甲神兵-Volt Prime
Published: 2016/05/28
Channel: Den. tw
Volt - Extrait n°2
Volt - Extrait n°2
Published: 2009/01/12
Channel: Disney FR
Nya Tricks Dubbel Trippel Volt
Nya Tricks Dubbel Trippel Volt
Published: 2017/07/29
Channel: Tomas och Malin
Volt - Extrait n°3
Volt - Extrait n°3
Published: 2009/02/02
Channel: Disney FR
Volt avec les pigeons!
Volt avec les pigeons!
Published: 2009/04/02
Channel: sbeldir
Volt , Un chat, un chien et un rongeur.
Volt , Un chat, un chien et un rongeur.
Published: 2013/03/16
Channel: AnimationZic
Тест-драйв Шевроле Volt от ORJEUNESSE
Тест-драйв Шевроле Volt от ORJEUNESSE
Published: 2017/08/18
Channel: АвтоЭнтерпрайз
What are VOLTs, OHMs & AMPs?
What are VOLTs, OHMs & AMPs?
Published: 2011/01/22
Channel: Daniel Sullivan
440 Volt Song | Sultan | Salman Khan | Anushka Sharma | Mika Singh
440 Volt Song | Sultan | Salman Khan | Anushka Sharma | Mika Singh
Published: 2016/06/14
Channel: YRF
VOLT Exklusiv Trailer German Deutsch (2017)
VOLT Exklusiv Trailer German Deutsch (2017)
Published: 2017/01/12
Channel: KinoCheck
Отрыв от батареи! Электромобили и как они устроены! Chevrolet Volt, Fiat500e
Отрыв от батареи! Электромобили и как они устроены! Chevrolet Volt, Fiat500e
Published: 2017/02/24
Channel: Ярослав Ефремов
VOLT Allstars + Zävodi: Jelszó: Love
VOLT Allstars + Zävodi: Jelszó: Love
Published: 2017/05/15
Channel: VOLT Fesztivál
Volt, star malgré lui - Bande-annonce
Volt, star malgré lui - Bande-annonce
Published: 2008/12/02
Channel: Disney FR
Volt Teaser 3
Volt Teaser 3
Published: 2014/10/28
Channel: Skylar Comics
Strom - Volt, Ampère, Ohm, Watt
Strom - Volt, Ampère, Ohm, Watt
Published: 2012/10/27
Channel: Liquidhimmel
쉐보레 2세대 볼트 시승기 Feat.나윤석(Chevrolet Volt review) - 2017.05.26
쉐보레 2세대 볼트 시승기 Feat.나윤석(Chevrolet Volt review) - 2017.05.26
Published: 2017/05/29
Channel: 한상기 Han Sang Ki
Wellhello x Halott Pénz - Emlékszem, Sopronban (a Telekom VOLT Fesztivál himnusza)
Wellhello x Halott Pénz - Emlékszem, Sopronban (a Telekom VOLT Fesztivál himnusza)
Published: 2015/05/20
Channel: VOLT Fesztivál
VOLT: Ataúd
VOLT: Ataúd
Published: 2015/10/23
Channel: VOLT ENERGY DRINK
VOLT 音源 (Groove Coaster 2)
VOLT 音源 (Groove Coaster 2)
Published: 2015/01/29
Channel: るけー
Volt - I Am Electro
Volt - I Am Electro
Published: 2016/09/30
Channel: Александр Шелементьев
Volt - Extrait n°1
Volt - Extrait n°1
Published: 2008/12/23
Channel: Disney FR
Pokemon XY Opening 1 [HD] [ENG Sub] - V (VOLT) by 遊助
Pokemon XY Opening 1 [HD] [ENG Sub] - V (VOLT) by 遊助
Published: 2014/01/29
Channel: cmdlabs
Gillette: Volt reclametest
Gillette: Volt reclametest
Published: 2008/10/15
Channel: Flabbergastedblog
Nuevo Volt Green
Nuevo Volt Green
Published: 2016/03/28
Channel: VOLT ENERGY DRINK
A 2016-os Volt Fesztivál legjobb pillanatai
A 2016-os Volt Fesztivál legjobb pillanatai
Published: 2016/07/03
Channel: Divatikon
VOLT FESZTIVÁL - 0. nap
VOLT FESZTIVÁL - 0. nap
Published: 2017/06/28
Channel: Sopronmédia
Volt & State - Sandcastles // OUT NOW
Volt & State - Sandcastles // OUT NOW
Published: 2015/08/03
Channel: ProtocolRecordings
【GROOVE COASTER 2】VOLT HARD FULLCHAIN
【GROOVE COASTER 2】VOLT HARD FULLCHAIN
Published: 2015/02/17
Channel: FUKA KEN
Optimistic Nihilism
Optimistic Nihilism
Published: 2017/07/26
Channel: Kurzgesagt – In a Nutshell
Which Way Is Down?
Which Way Is Down?
Published: 2017/11/02
Channel: Vsauce
Batman V Superman - Comedy Recap (HISHE Dubs)
Batman V Superman - Comedy Recap (HISHE Dubs)
Published: 2017/11/14
Channel: How It Should Have Ended
Lofi Hip Hop Radio 24/7 🎧 Chill Gaming / Study Beats
Lofi Hip Hop Radio 24/7 🎧 Chill Gaming / Study Beats
Published: 2017/09/26
Channel: Chillhop Music
TWICE "LIKEY" M/V
TWICE "LIKEY" M/V
Published: 2017/10/30
Channel: jypentertainment
Demi Lovato: Simply Complicated - Official Documentary
Demi Lovato: Simply Complicated - Official Documentary
Published: 2017/10/17
Channel: Demi Lovato
GTA V Häröilyä - Kaikki vihaavat Jallua
GTA V Häröilyä - Kaikki vihaavat Jallua
Published: 2014/08/26
Channel: MrJallu101
The Trump Presidency: Last Week Tonight with John Oliver (HBO)
The Trump Presidency: Last Week Tonight with John Oliver (HBO)
Published: 2017/11/13
Channel: LastWeekTonight
PSY - ‘New Face’ M/V
PSY - ‘New Face’ M/V
Published: 2017/05/10
Channel: officialpsy
Scotland vs Samoa rugby 11.11.2017 End-of-year rugby union internationals
Scotland vs Samoa rugby 11.11.2017 End-of-year rugby union internationals
Published: 2017/11/11
Channel: Planet Rugby
England v Australia - Michael Cheika & Michael Hooper Full Post Match Press Conference
England v Australia - Michael Cheika & Michael Hooper Full Post Match Press Conference
Published: 2017/11/18
Channel: BeanymanNews
England vs Wallabies highlights
England vs Wallabies highlights
Published: 2017/11/18
Channel: Rugby.com.au
The Chainsmokers & Coldplay - Something Just Like This (Lyric)
The Chainsmokers & Coldplay - Something Just Like This (Lyric)
Published: 2017/02/22
Channel: ChainsmokersVEVO
Tesla Model S v Holden V8 Supercar v Walkinshaw HSV GTS Drag Race
Tesla Model S v Holden V8 Supercar v Walkinshaw HSV GTS Drag Race
Published: 2015/10/05
Channel: CarAdvice.com
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WIKIPEDIA ARTICLE

From Wikipedia, the free encyclopedia
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Volt
NISTvoltChip.jpg
Josephson junction array chip developed by the National Bureau of Standards as a standard volt
Unit information
Unit system SI derived unit
Unit of Electric potential, electromotive force
Symbol V 
Named after Alessandro Volta
In SI base units: kg·m2·s−3·A−1

The volt (symbol: V) is the derived unit for electric potential, electric potential difference (voltage), and electromotive force.[1] It is named after the Italian physicist Alessandro Volta (1745–1827).

Definition[edit]

One volt is defined as the difference in electric potential between two points of a conducting wire when an electric current of one ampere dissipates one watt of power between those points.[2] It is also equal to the potential difference between two parallel, infinite planes spaced 1 meter apart that create an electric field of 1 newton per coulomb. Additionally, it is the potential difference between two points that will impart one joule of energy per coulomb of charge that passes through it. It can be expressed in terms of SI base units (m, kg, s, and A) as

It can also be expressed as amperes times ohms (current times resistance, Ohm's law), watts per ampere (power per unit current, Joule's law), or joules per coulomb (energy per unit charge), which is also equivalent to electronvolts per elementary charge:

Josephson junction definition[edit]

The "conventional" volt, V90, defined in 1988 by the 18th General Conference on Weights and Measures and in use from 1990, is implemented using the Josephson effect for exact frequency-to-voltage conversion, combined with the caesium frequency standard. For the Josephson constant, KJ = 2e/h (where e is the elementary charge and h is the Planck constant), the "conventional" value KJ-90 is used:

This standard is typically realized using a series-connected array of several thousand or tens of thousands of junctions, excited by microwave signals between 10 and 80 GHz (depending on the array design).[3] Empirically, several experiments have shown that the method is independent of device design, material, measurement setup, etc., and no correction terms are required in a practical implementation.[4]

Water-flow analogy[edit]

In the water-flow analogy sometimes used to explain electric circuits by comparing them with water-filled pipes, voltage (difference in electric potential) is likened to difference in water pressure. Current is proportional to the diameter of the pipe or the amount of water flowing at that pressure. A resistor would be a reduced diameter somewhere in the piping and a capacitor/inductor could be likened to a "U" shaped pipe where a higher water level on one side could store energy temporarily.

The relationship between voltage and current is defined (in ohmic devices like resistors) by Ohm's Law. Ohm's Law is analogous to the Hagen–Poiseuille equation, as both are linear models relating flux and potential in their respective systems.

Common voltages[edit]

A multimeter can be used to measure the voltage between two positions.
1.5 V C-cell batteries

The voltage produced by each electrochemical cell in a battery is determined by the chemistry of that cell. See Galvanic cell § Cell voltage. Cells can be combined in series for multiples of that voltage, or additional circuitry added to adjust the voltage to a different level. Mechanical generators can usually be constructed to any voltage in a range of feasibility.

Nominal voltages of familiar sources:

History[edit]

Alessandro Volta

In 1800, as the result of a professional disagreement over the galvanic response advocated by Luigi Galvani, Alessandro Volta developed the so-called voltaic pile, a forerunner of the battery, which produced a steady electric current. Volta had determined that the most effective pair of dissimilar metals to produce electricity was zinc and silver. In 1861, Latimer Clark and Sir Charles Bright coined the name "volt" for the unit of resistance.[9] By 1873, the British Association for the Advancement of Science had defined the volt, ohm, and farad.[10] In 1881, the International Electrical Congress, now the International Electrotechnical Commission (IEC), approved the volt as the unit for electromotive force.[11] They made the volt equal to 108 cgs units of voltage, the cgs system at the time being the customary system of units in science. They chose such a ratio because the cgs unit of voltage is inconveniently small and one volt in this definition is approximately the emf of a Daniell cell, the standard source of voltage in the telegraph systems of the day.[12] At that time, the volt was defined as the potential difference [i.e., what is nowadays called the "voltage (difference)"] across a conductor when a current of one ampere dissipates one watt of power.

Group photograph of Hermann Helmholtz, his wife (seated) and academic friends Hugo Kronecker (left), Thomas Corwin Mendenhall (right), Henry Villard (center) during the International Electrical Congress

The "international volt" was defined in 1893 as 1/1.434 of the emf of a Clark cell. This definition was abandoned in 1908 in favor of a definition based on the international ohm and international ampere until the entire set of "reproducible units" was abandoned in 1948.

Prior to the development of the Josephson junction voltage standard, the volt was maintained in national laboratories using specially constructed batteries called "standard cells". The United States used a design called the Weston cell from 1905 to 1972.

See also[edit]

References[edit]

  1. ^ "SI Brochure, Table 3 (Section 2.2.2)". BIPM. 2006. Retrieved 2007-07-29. 
  2. ^ BIPM SI Brochure: Appendix 1, p. 144
  3. ^ Burroughs, Charles J.; Bent, Samuel P.; Harvey, Todd E.; Hamilton, Clark A. (1999-06-01), "1 Volt DC Programmable Josephson Voltage Standard", IEEE Transactions on Applied Superconductivity, Institute of Electrical and Electronics Engineers (IEEE), 9 (3): 4145–4149, doi:10.1109/77.783938, ISSN 1051-8223, retrieved 2014-06-27 
  4. ^ Keller, Mark W (2008-01-18), "Current status of the quantum metrology triangle" (PDF), Metrologia, 45 (1): 102–109, Bibcode:2008Metro..45..102K, doi:10.1088/0026-1394/45/1/014, ISSN 0026-1394, Theoretically, there are no current predictions for any correction terms. Empirically, several experiments have shown that KJ and RK are independent of device design, material, measurement setup, etc. This demonstration of universality is consistent with the exactness of the relations, but does not prove it outright. 
  5. ^ Bullock, Orkand, and Grinnell, pp. 150–151; Junge, pp. 89–90; Schmidt-Nielsen, p. 484
  6. ^ Hill, Paul Horowitz; Winfield; Winfield, Hill (2015). The Art of Electronics (3. ed.). Cambridge [u.a.]: Cambridge Univ. Press. p. 689. ISBN 978-0-521-809269. 
  7. ^ SK Loo and Keith Keller (Aug 2004). "Single-cell Battery Discharge Characteristics Using the TPS61070 Boost Converter" (PDF). Texas Instruments. 
  8. ^ 2012-2013 Model S Emergency Response Guide (PDF), retrieved 2017-08-06 
  9. ^ As names for units of various electrical quantities, Bright and Clark suggested "ohma" for voltage, "farad" for charge, "galvat" for current, and "volt" for resistance. See:
  10. ^ Sir W. Thomson, et al. (1873) "First report of the Committee for the Selection and Nomenclature of Dynamical 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 by the original standard coil, is approximately 109 C.G.S. units of resistance ; the "volt" is approximately 108 C.G.S. units of electromotive force ; and the "farad" is approximately 1/109 of the C.G.S. unit of capacity."
  11. ^ (Anon.) (September 24, 1881) "The Electrical Congress," The Electrician, 7 : 297.
  12. ^ Hamer, Walter J. (January 15, 1965). Standard Cells: Their Construction, Maintenance, and Characteristics (PDF). National Bureau of Standards Monograph #84. US National Bureau of Standards. 

External links[edit]

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