The ampere (symbol: A) is the SI base unit of electrical current equal to one coulomb per second. It is named after André-Marie Ampère, one of the main discoverers of electromagnetism. The SI system of units defines seven SI base units: fundamental physical units defined by an operational definition. ...
In electricity, current refers to electric current, which is the flow of electric charge. ...
The coulomb (symbol: C) is the SI unit of electric charge. ...
André-Marie Ampère (January 20, 1775 – June 10, 1836), was a French physicist who is generally credited as one of the main discoverers of electromagnetism. ...
Electromagnetism is the physics of the electromagnetic field: a field, encompassing all of space, which exerts a force on those particles that possess the property of electric charge, and is in turn affected by the presence and motion of such particles. ...
Definition
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 metre apart in vacuum, would produce between these conductors a force equal to 2×10–7 newton per metre of length. The metre (Commonwealth English) or meter (American English) (symbol: m) is the SI base unit of length. ...
The newton (symbol: N) is the SI unit of force. ...
Explanation Because it is a base unit, the definition of the ampere is not tied to any other electrical unit. The definition for the ampere is equivalent to fixing a value of the permeability of vacuum to μ0 = 4π×10−7 H/m. Prior to 1948, the so-called "international ampere" was used, defined in terms of the electrolytic deposition rate of silver. The older unit is equal to 0.999 85 A. In electromagnetism, permeability is the degree of magnetisation of a material that responds linearly to an applied magnetic field. ...
In chemistry and manufacturing, electrolysis is a method of separating bonded elements and compounds by passing an electric current through them. ...
General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Atomic mass 107. ...
The ampere is most accurately realised using an ampere balance, but is in practice maintained via Ohm's Law from the units of voltage and resistance, the volt and the ohm, since the latter two can be tied to physical phenomena that are relatively easy to reproduce, the Josephson junction and the quantum Hall effect, respectively. The ampere balance (also current balance or Kelvin balance) is an electromechanical apparatus used for the precise measurement of the SI unit of electric current, the ampere. ...
Ohms law, named after its discoverer Georg Ohm [1], states that the potential difference or voltage drop (U or V) between the ends of a conductor and the current (I) flowing through the conductor are proportional at a given temperature: The equation contains the proportionality constant R, which is...
This article may be too technical for most readers to understand. ...
Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ...
The volt (symbol: V) is the SI derived unit of electric potential difference. ...
Ohm may refer to: The scientist Georg Ohm. ...
Josephson junctions, first postulated by B. D. Josephson and first made by John Rowell and Philip Anderson, are quantum-mechanical circuit elements of superconducting devices. ...
The quantum Hall effect is a quantum-mechanical version of the Hall effect, observed in two-dimensional systems of electrons subjected to low temperatures and strong magnetic fields, in which the Hall conductance σ takes on the quantized values where e is the elementary charge and h is Plancks constant. ...
The unit of electric charge, the coulomb, is defined in terms of the ampere: one coulomb is the amount of electric charge (formerly quantity of electricity) carried in a current of one ampere flowing for one second. Current (electricity), then, is the rate at which charge flows through a wire or surface. One ampere of current (I) is equal to a flow of one coulomb of charge (Q) per second of time (t): Electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interactions. ...
The coulomb (symbol: C) is the SI unit of electric charge. ...
In physics the term Quantity of Electricity refers to the quantity of electric charge. ...
Look up second in Wiktionary, the free dictionary. ...
In electricity, current refers to electric current, which is the flow of electric charge. ...
The coulomb (symbol: C) is the SI unit of electric charge. ...
 Since a coulomb is approximately equal to 6.24×1018 elementary charges, one ampere is equivalent to 6.24×1018 elementary charges, such as electrons, moving through a surface in one second. More precisely, using the SI definitions for the conventional values of the Josephson and von Klitzing constants, the ampere can be defined as exactly 6.241 509 629 152 65×1018 elementary charges per second. Properties The electron is a fundamental subatomic particle which carries a negative electric charge. ...
The magnetic flux quantum Φ0 is the quantum of magnetic flux passing through a superconductor. ...
The quantum Hall effect is a quantum mechanical version of the Hall effect, observed in two-dimensional systems of electrons subjected to low temperatures and strong magnetic fields, in which the Hall conductance σ takes on the quantized values where e is the elementary charge and h is Plancks...
See also The International System of Units (abbreviated SI from the French language name Système International dUnités) is the modern form of the metric system. ...
Ohms law, named after its discoverer Georg Ohm [1], states that the potential difference or voltage drop (U or V) between the ends of a conductor and the current (I) flowing through the conductor are proportional at a given temperature: The equation contains the proportionality constant R, which is...
Sign warning of possible electric shock hazard Electrocution redirects here; for deliberate execution by electric shock, see electric chair. ...
External links - A short history of the SI units in electricity
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