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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] |
Statohm
The statohm (symbol: statΩ) is the unit of electrical resistance in the electrostatic system of units which was part of the CGS system of units based upon the centimetre, gram and second. The static units in that system are related to the corresponding electromagnetic units by a factor of the speed of light. Those units are known as absolute units, and so the counterpart of the statohm is the abohm (abΩ), and their proportions are: 1 statΩ ≘ ''c''2 abΩ ≈ abΩ where ''c'' is the speed of light in centimetres per second. These units are not common now. The SI unit of resistance is the ohm (Ω). The statohm is nearly a trillion ''Trillion'' is a number with two distinct definitions: *1,000,000,000,000, i.e. one million 1,000,000, million, or (ten to the twelfth Exponentiation, power), as defined on the long and short scales, short scale. This is now the meaning in bot ... times larger than the ohm and is the largest unit of resistance ever used in any measurement s ... [...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] |
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] |
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] |
Electrical Resistance
The electrical resistance of an object is a measure of its opposition to the flow of electric current. Its reciprocal quantity is , measuring the ease with which an electric current passes. Electrical resistance shares some conceptual parallels with mechanical friction. The SI unit of electrical resistance is the ohm (), while electrical conductance is measured in siemens (S) (formerly called the 'mho' and then represented by ). The resistance of an object depends in large part on the material it is made of. Objects made of electrical insulators like rubber tend to have very high resistance and low conductance, while objects made of electrical conductors like metals tend to have very low resistance and high conductance. This relationship is quantified by resistivity or conductivity. The nature of a material is not the only factor in resistance and conductance, however; it also depends on the size and shape of an object because these properties are extensive rather tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centimetre–gram–second 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] |
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] |
Heaviside–Lorentz Units
Heaviside–Lorentz units (or Lorentz–Heaviside units) constitute a system of units and quantities that extends the CGS with a particular set of equations that defines electromagnetic quantities, named for Oliver Heaviside and Hendrik Antoon Lorentz. They share with the CGS-Gaussian system that the electric constant and magnetic constant do not appear in the defining equations for electromagnetism, having been incorporated implicitly into the electromagnetic quantities. Heaviside–Lorentz units may be thought of as normalizing and , while at the same time revising Maxwell's equations to use the speed of light instead. The Heaviside–Lorentz unit system, like the International System of Quantities upon which the SI system is based, but unlike the CGS-Gaussian system, is ''rationalized'', with the result that there are no factors of appearing explicitly in Maxwell's equations.Kowalski, Ludwik, 1986,A Short History of the SI Units in Electricity " ''The Physics Teacher' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centimetre–gram–second 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] |
Gaussian Units
Gaussian units constitute a metric system of units of measurement. This system is the most common of the several electromagnetic unit systems based on the centimetre–gram–second system of units (CGS). It is also called the Gaussian unit system, Gaussian-cgs units, or often just cgs units. The term "cgs units" is ambiguous and therefore to be avoided if possible: there are several variants of CGS, which have conflicting definitions of electromagnetic quantities and units. International System of Units, SI units predominate in most fields, and continue to increase in popularity at the expense of Gaussian units. Alternative unit systems also exist. Conversions between quantities in the Gaussian and SI systems are direct unit conversions, because the quantities themselves are defined differently in each system. This means that the equations that express physical laws of electromagnetism—such as Maxwell's equations—will change depending on the system of quantities that is emp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centimetre Gram Second System Of Units
upright=1.35, Different lengths as in respect to the electromagnetic spectrum, measured by the metre and its derived scales. The microwave is in-between 1 meter to 1 millimeter. A centimetre (International spelling) or centimeter (American English), with SI symbol cm, is a Units of measurement, unit of length in the International System of Units (SI) equal to one hundredth of a metre, ''centi-'' being the SI prefix for a factor of . Equivalently, there are 100 centimetres in 1 metre. The centimetre was the base unit of length in the now deprecated centimetre–gram–second (CGS) system of units. Though for many physical quantities, SI prefixes for factors of 103—like ''milli-'' and ''kilo-''—are often preferred by technicians, the centimetre remains a practical unit of length for many everyday measurements; for instance, human height is commonly measured in centimetres. A centimetre is approximately the width of the fingernail of an average adult person. Equivalence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
