Josephson junction array chip developed by NIST as a standard volt.

For the electric plug-in hybrid concept car, see Chevrolet Volt.

For the record label, see Volt Records

The volt (symbol: V) is the SI derived unit of electric potential difference or electromotive force ^[1]. It is named in honor of the Italian physicist Alessandro Volta (1745–1827), who invented the voltaic pile, the first modern chemical battery. ImageMetadata File history File links NISTvoltChip. ... ImageMetadata File history File links NISTvoltChip. ... As a non-regulatory agency of the United States Department of Commerce’s Technology Administration, the National Institute of Standards (NIST) develops and promotes measurement, standards, and technology to enhance productivity, facilitate trade, and improve the quality of life. ... The Chevrolet Volt is a plug-in hybrid concept car created by General Motors. ... Volt Records was a subsidiary of Stax Records, started in 1965. ... Look up si, Si, SI in Wiktionary, the free dictionary. ... SI derived units are part of the SI system of measurement units and are derived from the seven SI base units. ... Potential difference is a quantity in physics related to the amount of energy that would be required to move an object from one place to another against various types of force. ... Electromotive force (emf) is the amount of energy gained per unit charge that passes through a device in the opposite direction to the electric field existing across that device. ... Articles with similar titles include physician, a person who practices medicine. ... Count Alessandro Giuseppe Antonio Anastasio Volta (February 18, 1745 - March 5, 1827) was an Italian physicist known especially for the development of the electric battery in 1800. ... A copper-zinc Voltaic pile The Voltaic pile was the first modern electric battery, invented by Alessandro Volta in 1800. ... Four double-A (AA) rechargeable cells A Duracell AA alkaline cell In science and technology, a galvanic cell is an electrochemical cell that stores chemical energy and makes it available in an electrical form, and a battery is a string of two or more cells in series. ...

Definition

The volt is defined as the potential difference across a conductor when a current of one ampere dissipates one watt of power. Hence, it is the base SI representation m² · kg · s^-3 · A^-1, which can be equally represented as one joule of energy per coulomb of charge, J/C. Potential difference is a quantity in physics related to the amount of energy that would be required to move an object from one place to another against various types of force. ... Electric current is the flow (movement) of electric charge. ... Current can be measured by a galvanometer, via the deflection of a magnetic needle in the magnetic field created by the current. ... The watt (symbol: W) is the SI derived unit of power, equal to one joule per second. ... In physics, power (symbol: P) is the rate at which work is performed or energy is transferred. ... The or meter (see spelling differences) is a measure of length. ... The U.S. National Prototype Kilogram, which currently serves as the primary standard for measuring mass in the U.S. It was assigned to the United States in 1889 and is periodically recertified and traceable to the primary international standard, The Kilogram, held at the Bureau International des Poids et... Look up second in Wiktionary, the free dictionary. ... Current can be measured by a galvanometer, via the deflection of a magnetic needle in the magnetic field created by the current. ... The joule (IPA pronunciation: or ) (symbol: J) is the SI unit of energy. ... The coulomb (symbol: C) is the SI unit of electric charge. ...

Josephson junction definition

Since 1990 the volt is maintained internationally for practical measurement using the Josephson effect, where a conventional value is used for the Josephson constant, fixed by the 18th General Conference on Weights and Measures as The Josephson effect is the phenomenon of current flow across two weakly coupled superconductors, separated by a very thin insulating barrier. ... The magnetic flux quantum Φ0 is the quantum of magnetic flux passing through a superconductor. ... The General Conference on Weights and Measures is the English name of the Conférence générale des poids et mesures (CGPM, never GCWM). ...

K_{J-90} = 0.4835979 GHz/µV.

Hydraulic analogy

In the hydraulic analogy sometimes used to explain electric circuits by comparing them to water-filled pipes, voltage is likened to water pressure - it determines how fast the electrons will travel through the circuit. Current (in amperes), in the same analogy, is a measure of the volume of water that flows past a given point, the rate of which is determined by the voltage, and the total output measured in watts. The equation that brings all three components together is: volts × amperes = watts Since electric current is invisible and the processes at play in electronics are often difficult to understand in an intuitive way, it is common to teach electronics using analogies to more common sense objects and processes. ... International safety symbol Caution, risk of electric shock (ISO 3864), colloquially known as high voltage symbol. ...

Common voltages

A multimeter can be used to measure the voltage between two points

1.5 V C-cell batteries

Nominal voltages of familiar sources: Image File history File links Download high-resolution version (1600x1067, 265 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Ampere Volt Ohm ... Image File history File links Download high-resolution version (1600x1067, 265 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Ampere Volt Ohm ... ImageMetadata File history File links Download high resolution version (640x604, 41 KB) File links The following pages link to this file: Volt ... ImageMetadata File history File links Download high resolution version (640x604, 41 KB) File links The following pages link to this file: Volt ...

• Nerve cell action potential: around 75 mV
• Single-cell, rechargeable NiMH or NiCd battery: 1.2 V
• Mercury battery 1.355 V
• Single-cell, non-rechargeable alkaline battery (e.g. AAA, AA, C and D cells): 1.5 V
• Lithium polymer rechargeable battery: 3.75 V
• Transistor-transistor logic (TTL) power supply: 5 V
• PP3 battery: 9 V
• Automobile electrical system: "12 V", about 11.8 V discharged, 12.8 V charged, and 13.8-14.4 V while charging (vehicle running).
• Household mains electricity: 240 V RMS in Australia, 230 V RMS in Europe, Asia and Africa, 120 V RMS in North America, 100 V RMS in Japan (see List of countries with mains power plugs, voltages and frequencies)
• Rapid transit third rail: 600 to 700 V (see List of current systems for electric rail traction)
• High speed train overhead power lines: 25 kV RMS at 50 Hz, but see List of current systems for electric rail traction for exceptions.
• High voltage electric power transmission lines: 110 kV RMS and up (1150 kV RMS is the record as of 2005)
• Lightning: Varies greatly, often around 100 MV.

Note: Where 'RMS' (root mean square) is stated above, the peak voltage is times greater than the RMS voltage for a sinusoidal signal. Neurons (also called nerve cells) are the primary cells of the nervous system. ... A. A schematic view of an idealized action potential illustrates its various phases as the action potential passes a point on a cell membrane. ... This article does not cite its references or sources. ... The nickel-cadmium battery (commonly abbreviated NiCd and pronounced nye-cad) is a popular type of rechargeable battery for portable electronics and toys using the metals nickel (Ni) and cadmium (Cd) as the active chemicals. ... A Mercury battery (also called mercuric oxide battery, or mercury cell) is a non-rechargeable electrochemical battery, a primary cell. ... A Duracell AA alkaline battery 2 Duracell-Brand AAA Alkaline batteries Alkaline batteries are a type of power cell dependent upon the reaction between zinc and manganese dioxide (Zn/MnO2). ... Four double-A (AA) rechargeable cells A Duracell AA alkaline cell In science and technology, a galvanic cell is an electrochemical cell that stores chemical energy and makes it available in an electrical form, and a battery is a string of two or more cells in series. ... Lithium polymer batteries (Li-Poly or LiPo) are rechargeable batteries which have technologically evolved from lithium ion batteries. ... A Motorola 68000-based computer with various TTL chips. ... PP3 (9 volt) batteries A PP3 battery, commonly referred to simply as a nine-volt battery, is shaped as a rounded rectangular prism and has a nominal output of nine volts. ... Karl Benzs Velo (vélo means bicycle in French) model (1894) - entered into the first automobile race 2005 MINI Cooper S. An automobile (also motor car or simply car) is a wheeled passenger vehicle that carries its own motor. ... Type F Mains power plug & socket The term “mains” usually refers to the general purpose AC electrical power supply (as in “Ive connected the appliance to the mains”). The term is not usually used in the United States and Canada. ... The terms line voltage/frequency or mains voltage/frequency commonly refer to the electrical voltage and frequency used in the low voltage parts (in particular wall sockets) of an alternating current electricity supply network. ... A rapid transit, underground, subway, tube, elevated, or metro(politan) system is a railway—usually in an urban area—with a high capacity and frequency of service, and grade separation from other traffic. ... Third rail at the West Falls Church Metro stop in Washington, D.C., electrified to 750 volts. ... This a list of the voltages, etc. ... This a list of the voltages, etc. ... Power line redirects here. ... This article needs additional references or sources to facilitate its verification. ... In mathematics, the root mean square or rms is a statistical measure of the magnitude of a varying quantity. ... In mathematics, the trigonometric functions are functions of an angle, important when studying triangles and modeling periodic phenomena. ...

History of the volt

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 the 1880s, the International Electrical Congress, now the International Electrotechnical Commission (IEC), approved the volt for electromotive force. The volt was defined as the potential difference across a conductor when a current of one ampere dissipates one watt of power. Luigi Galvani - Italian physician famous for making frogs legs twitch. ... A copper-zinc Voltaic pile The Voltaic pile was the first modern electric battery, invented by Alessandro Volta in 1800. ... Four double-A (AA) rechargeable cells A Duracell AA alkaline cell In science and technology, a galvanic cell is an electrochemical cell that stores chemical energy and makes it available in an electrical form, and a battery is a string of two or more cells in series. ... In electricity, current refers to electric current, which is the flow of electric charge. ... General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Standard atomic weight 65. ... General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Standard atomic weight 107. ... The International Electrotechnical Commission (IEC) is an international standards organization dealing with electrical, electronic and related technologies. ... Current can be measured by a galvanometer, via the deflection of a magnetic needle in the magnetic field created by the current. ... The watt (symbol: W) is the SI derived unit of power, equal to one joule per second. ...

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. The Weston cell, invented by Edward Weston in 1893, is a wet-chemical cell (colloquially: battery) that produces a highly stable voltage suitable as a laboratory standard for calibration of voltmeters. ... The Weston cell, invented by Edward Weston in 1893, is a wet-chemical cell (colloquially: battery) that produces a highly stable voltage suitable as a laboratory standard for calibration of voltmeters. ...

This SI unit is named after Alessandro Volta. As for all SI units whose names are derived from the proper name of a person, the first letter of its symbol is uppercase (V). But when an SI unit is spelled out, it should always be written in lowercase (volt), unless it begins a sentence or is the name "degree Celsius". — Based on The International System of Units, section 5.2.

Image File history File links SI_Brochure_Cover. ... Look up si, Si, SI in Wiktionary, the free dictionary. ... Count Alessandro Giuseppe Antonio Anastasio Volta (February 18, 1745 - March 5, 1827) was an Italian physicist known especially for the development of the electric battery in 1800. ... Majuscules or capital letters (in the Roman alphabet: A, B, C, ...) are one type of case in a writing system. ... Minuscule, or lower case, is the smaller form (case) of letters (in the Roman alphabet: a, b, c, ...). Originally alphabets were written entirely in majuscule (capital) letters which were spaced between well-defined upper and lower bounds. ... Celsius is, or relates to, the Celsius temperature scale (previously known as the centigrade scale). ...

See also

• SI for unit prefixes
• SI electromagnetism units
• Voltmeter
• Watt
• Ampere

Look up si, Si, SI in Wiktionary, the free dictionary. ... ... Two digital voltmeters. ... The watt (symbol: W) is the SI derived unit of power, equal to one joule per second. ... Current can be measured by a galvanometer, via the deflection of a magnetic needle in the magnetic field created by the current. ...

References

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