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Abvolt
The abvolt (abV) is the unit of potential difference in the CGS-EMU system of units. It corresponds to in the SI system and 1/ statvolt ≈ in the CGS-ESU system. A potential difference of 1 abV will drive a current of one abampere through a resistance of one abohm. In most practical applications, the volt and its multiples are preferred. The national standard in the United States deprecates the use of the abvolt, suggesting the use of volts instead. The name abvolt was introduced by Kennelly in 1903 as a short name for the long name ''(absolute) electromagnetic cgs unit of e.m.f.'' that was in use since the adoption of the cgs system in 1875.A.E. Kennelly (1903"Magnetic units and other subjects that might occupy attention at the next international electrical congress"''20th Annual Convention of the American Institute of Electrical Engineers, 1903'' The abvolt was coherent Coherence is, in general, a state or situation in which all the parts or ideas fit together well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Statvolt
The statvolt is a unit of voltage and electrical potential used in the CGS-ESU and gaussian systems of units. In terms of its relation to the SI units, one statvolt corresponds to , i.e. to 299.792458 volts. The statvolt is also defined in the CGS system as 1 erg per statcoulomb. It is a useful unit for electromagnetism because, in vacuum, an electric field of one statvolt per centimetre has the same energy density as a magnetic field of one gauss. Likewise, a plane wave propagating in vacuum has perpendicular electric and magnetic fields such that for every gauss of magnetic field intensity there is one statvolt/cm of electric field intensity. In the CGS-EMU system, the unit of voltage is the abvolt. Additional Information The statvolt is a fundamental unit of electric potential in the centimetre-gram-second electrostatic unit (CGS-ESU) and Gaussian unit systems. It is defined as the potential difference between two points that imparts one erg of energy p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centimetre%E2%80%93gram%E2%80%93second System Of Units
The centimetre–gram–second system of units (CGS or cgs) is a variant of the metric system based on the centimetre as the unit of length, the gram as the unit of mass, and the second as the unit of time. All CGS mechanical units are unambiguously derived from these three base units, but there are several different ways in which the CGS system was extended to cover electromagnetism. The CGS system has been largely supplanted by the MKS system based on the metre, kilogram, and second, which was in turn extended and replaced by the International System of Units (SI). In many fields of science and engineering, SI is the only system of units in use, but CGS is still prevalent in certain subfields. In measurements of purely mechanical systems (involving units of length, mass, force, energy, pressure, and so on), the differences between CGS and SI are straightforward: the unit-conversion factors are all powers of 10 as and . For example, the CGS unit of force is the dyne, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abampere
The abampere (abA), also called the biot (Bi) after Jean-Baptiste Biot, is the derived electromagnetic unit of electric current in the emu-cgs system of units (electromagnetic cgs). One abampere corresponds to ten amperes in the SI system of units. An abampere of current in a circular path of one centimeter radius produces a magnetic field of 2π oersteds at the center of the circle. The name abampere was introduced by Kennelly in 1903 as a short name for the long name ''(absolute) electromagnetic cgs unit of current'' that was in use since the adoption of the cgs system in 1875.A.E. Kennelly (1903"Magnetic units and other subjects that might occupy attention at the next international electrical congress"''20th Annual Convention of the American Institute of Electrical Engineers, 1903'' The abampere was coherent with the emu-cgs system, in contrast to the ampere, the practical unit of current that had been adopted too in 1875. The emu-cgs (or "electromagnetic cgs") u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Potential
Electric potential (also called the ''electric field potential'', potential drop, the electrostatic potential) is defined as electric potential energy per unit of electric charge. More precisely, electric potential is the amount of work (physics), work needed to move a test charge from a reference point to a specific point in a static electric field. The test charge used is small enough that disturbance to the field is unnoticeable, and its motion across the field is supposed to proceed with negligible acceleration, so as to avoid the test charge acquiring kinetic energy or producing radiation. By definition, the electric potential at the reference point is zero units. Typically, the reference point is Earth (electricity), earth or a point at infinity, although any point can be used. In classical electrostatics, the electrostatic field is a vector quantity expressed as the gradient of the electrostatic potential, which is a scalar (physics), scalar quantity denoted by or occasi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abohm
The abohm is the derived unit of electrical resistance in the emu-cgs ''(centimeter-gram-second)'' system of units (emu stands for "electromagnetic units"). One abohm corresponds to 10−9 ohms in the SI system of units, which is a nanoohm. The emu-cgs (or "electromagnetic cgs") units are one of several systems of electromagnetic units within the centimetre gram second system of units; others include esu-cgs, Gaussian units, and Heaviside–Lorentz units. In these other systems, the abohm is ''not'' one of the units. When a current of one abampere (1 abA) flows through a resistance of 1 abohm, the resulting potential difference across the component is one abvolt (1 abV). The name abohm was introduced by Kennelly in 1903 as a short name for the long name ''(absolute) electromagnetic cgs unit of resistance'' that was in use since the adoption of the cgs system in 1875.A.E. Kennelly (1903"Magnetic units and other subjects that might occupy attention at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coherence (units Of Measurement)
A coherent system of units is a system of units of measurement used to express physical quantities that are defined in such a way that the equations relating the numerical values expressed in the units of the system have exactly the same form, including numerical factors, as the corresponding equations directly relating the quantities. It is a system in which every quantity has a unique unit, or one that does not use conversion factors. A coherent derived unit is a derived unit that, for a given system of quantities and for a chosen set of base units, is a product of powers of base units, with the proportionality factor being one. If a system of quantities has equations that relate quantities and the associated system of units has corresponding base units, with only one unit for each base quantity, then it is coherent if and only if every derived unit of the system is coherent. The concept of coherence was developed in the mid-nineteenth century by, amongst others, Kelvin a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthur E
Arthur is a masculine given name of uncertain etymology. Its popularity derives from it being the name of the legendary hero King Arthur. A common spelling variant used in many Slavic, Romance, and Germanic languages is Artur. In Spanish and Italian it is Arturo. Etymology The earliest attestation of the name Arthur is in the early 9th century Welsh-Latin text '' Historia Brittonum'', where it refers to a circa 5th century Romano-British general who fought against the invading Saxons, and who later gave rise to the famous King Arthur of medieval legend and literature. A possible earlier mention of the same man is to be found in the epic Welsh poem '' Y Gododdin'' by Aneirin, which some scholars assign to the late 6th century, though this is still a matter of debate and the poem only survives in a late 13th century manuscript entitled the Book of Aneirin. A 9th-century Breton landowner named Arthur witnessed several charters collected in the '' Cartulary of Redon''. The Iris ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System Of Measurement
A system of units of measurement, also known as a system of units or system of measurement, is a collection of units of measurement and rules relating them to each other. Systems of measurement have historically been important, regulated and defined for the purposes of science and wikt:commerce, commerce. Instances in use include the International System of Units or (the modern form of the metric system), the British imperial system, and the United States customary system. History In antiquity, ''systems of measurement'' were defined locally: the different units might be defined independently according to the length of a king's thumb or the size of his foot, the length of stride, the length of arm, or maybe the weight of water in a keg of specific size, perhaps itself defined in ''hands'' and ''knuckles''. The unifying characteristic is that there was some definition based on some standard. Eventually ''cubits'' and ''yard, strides'' gave way to "customary units" to meet the n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speed Of Light
The speed of light in vacuum, commonly denoted , is a universal physical constant exactly equal to ). It is exact because, by international agreement, a metre is defined as the length of the path travelled by light in vacuum during a time interval of second. The speed of light is invariant (physics), the same for all observers, no matter their relative velocity. It is the upper limit for the speed at which Information#Physics_and_determinacy, information, matter, or energy can travel through Space#Relativity, space. All forms of electromagnetic radiation, including visible light, travel at the speed of light. For many practical purposes, light and other electromagnetic waves will appear to propagate instantaneously, but for long distances and sensitive measurements, their finite speed has noticeable effects. Much starlight viewed on Earth is from the distant past, allowing humans to study the history of the universe by viewing distant objects. When Data communication, comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SI Derived Units
SI derived units are units of measurement derived unit, derived from the seven SI base units specified by the International System of Units (SI). They can be expressed as a product (or ratio) of one or more of the base units, possibly scaled by an appropriate power (mathematics), power of exponentiation (see: Buckingham π theorem). Some are dimensionless quantity, dimensionless, as when the units cancel out in ratios of like quantities. SI coherent derived units involve only a trivial proportionality factor, not requiring conversion factors. The SI has special names for 22 of these coherent derived units (for example, hertz, the SI unit of measurement of frequency), but the rest merely reflect their derivation: for example, the square metre (m2), the SI derived unit of area; and the kilogram per cubic metre (kg/m3 or kg⋅m−3), the SI derived unit of density. The names of SI coherent derived units, when written in full, are always in lowercase. However, the symbols for units n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
