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Encyclopedia > Conductor (material)

In science and engineering, conductors are materials that contain movable charges of electricity. When an electric potential difference is impressed across separate points on a conductor, the mobile charges within the conductor are forced to move, and an electric current between those points appears in accordance with Ohm's law. While many conductors are metallic, there are many non-metallic conductors as well, including all plasmas. See electrical conduction for more information on the physical mechanism for charge flow in materials. Wikimedia Commons has media related to: Science For the scientific journal named Science, see Science (journal). ... Engineering applies scientific and technical knowledge to solve human problems. ... Lightning strikes during a night-time thunderstorm. ... Ohms law, named after its discoverer Georg Ohm [1], states that the potential difference between two points, or equivalently the voltage drop from one point to a second point, usually designated by U or V, of a device capable of conducting an electrical current and the current I flowing... Hot metal work from a blacksmith In chemistry, a metal (Greek: Metallon) is an element that readily forms ions (cations) and has metallic bonds, and metals are sometimes described as a lattice of positive ions (cations) in a cloud of electrons. ... A Plasma lamp, illustrating some of the more complex phenomena of a plasma, including filamentation In physics and chemistry, a plasma is an ionized gas, and is usually considered to be a distinct phase of matter. ... Electrical conduction is the movement of electrically charged particles through matter. ...


Under normal conditions, all materials offer some resistance to flowing charges, which generates heat. Thus, proper design of an electrical conductor includes an estimate of the temperature that the conductor is expected to endure without damage, as well as the quantity of electrical current. The motion of charges also creates an electromagnetic field around the conductor that exerts a mechanical radial squeezing force on the conductor. A conductor of a given material and volume (length x cross-sectional area) has no real limit to the current it can carry without being destroyed as long as the heat generated by the resistive loss is removed and the conductor can withstand the radial forces. This effect is especially critical in printed circuits, where conductors are relatively small and the heat produced, if not properly removed, can cause fusing of the tracks. To meet Wikipedias quality standards, this article or section may require cleanup. ... Close-up photo of one side of a motherboard PCB, showing conductive traces, vias and solder points for through-hole components on the opposite side. ...


Non-conducting materials lack mobile charges and are called insulators. A material can be an electrical conductor without being a thermal conductor, although a metal can be both an electrical conductor and a thermal conductor. Electrically conductive materials are usually classified according to their electrical resistance; ranging from high to null resistance, there are semiconductors, ordinary metallic conductors (also called normal metals), and superconductors. This article is in need of attention from an expert on the subject. ... Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ... A semiconductor is a material with an electrical conductivity that is intermediate between that of an insulator and a conductor. ... Hot metal work from a blacksmith In chemistry, a metal (Greek: Metallon) is an element that readily forms ions (cations) and has metallic bonds, and metals are sometimes described as a lattice of positive ions (cations) in a cloud of electrons. ... Superconductivity is a phenomenon occurring in certain materials at low temperatures, characterised by the complete absence of electrical resistance and the damping of the interior magnetic field (the Meissner effect. ...

Contents


Power engineering

In power engineering, a conductor is a piece of metal used to conduct electricity, known colloquially as an electrical wire. Power engineering is the field of electrical engineering that deals with power systems, specifically electric power transmission and distribution, power conversion, and electromechanical devices. ... Electrical wiring in general refers to conductors used to carry electricity, and their accessories. ...


Conductor size

In United States, conductors are measured by American wire gauge for smaller ones, and circular mils for larger ones. American wire gauge (AWG) is used in the United States and other countries as a standard method of denoting wire diameter, especially for nonferrous, electrically conducting wire. ...


For example, a '4/0' conductor is about a half inch in diameter, while a '795 000' conductor is about an inch in diameter. In other places, conductors are often measured by their cross section in square millimeters.


Conductor materials

Of the metals commonly used for conductors, copper has the highest conductivity. Silver is more conductive, but due to cost it is not practical except as a thin plating to mitigate skin effect losses at high frequencies. Because of its ease of connection by soldering or clamping, copper is still the most common choice for most light-gauge wires. General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance metallic brown Atomic mass 63. ... Electrical conductivity is a measure of how well a material accommodates the transport of electric charge. ... 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 skin effect is the tendency of an alternating electric current to distribute itself within a conductor so that the current density near the surface of the conductor is greater than that at its core. ... (De)soldering a contact from a wire. ...


Compared to copper, aluminium has worse conductivity per unit volume, but better conductivity per unit weight. In many cases, weight is more important than volume making aluminium the 'best' conductor material for certain applications. For example, it is commonly used for large-scale power distribution conductors such as overhead power lines. In many such cases, aluminium is used over a steel core that provides much greater tensile strength than would the aluminium alone [1][2]. General Name, Symbol, Number aluminium, Al, 13 Chemical series poor metals Group, Period, Block 13, 3, p Appearance silvery Atomic mass 26. ... Transmission towers Transmission lines in Lund, Sweden Electric power transmission, or more accurately Electrical energy transmission, is the second process in the delivery of electricity to consumers. ...


Gold is occasionally used for very fine wires such as those used to wire bond integrated circuits to their lead frames. Despite popular belief, it is a misconception that Gold is a better conductor for electrical connectors, it is because of its resistance to surface corrosion (commonly suffered by Copper and Silver which has a detrimental effect on connection quality) that electrical connectors are often gold-plated. General Name, Symbol, Number gold, Au, 79 Chemical series transition metals Group, Period, Block 11, 6, d Appearance metallic yellow Atomic mass 196. ... Wire bonding is a method of making interconnections between a microchip and the outside world as part of semiconductor device fabrication. ... SEM image of an integrated circuit showing defects in the aluminium layer deposition (shown in cyan). ... General Name, Symbol, Number gold, Au, 79 Chemical series transition metals Group, Period, Block 11, 6, d Appearance metallic yellow Atomic mass 196. ... General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance metallic brown Atomic mass 63. ... General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Atomic mass 107. ...


Conductor voltage

The voltage on a conductor is determined by the connected circuitry and has nothing to do with the conductor itself. Conductors are usually surrounded by and/or supported by insulators and the insulation determines the maximum voltage that can be applied to any given conductor. This article may be too technical for most readers to understand. ... // Definition An Insulator is a material or object which resists the flow of electric charge. ...


Conductor ampacity

The ampacity of a conductor, that is, the amount of current it can carry, is related to its electrical resistance: a lower-resistance conductor can carry more current. The resistance, in turn, is determined by the material the conductor is made from (as described above) and the conductor's size. For a given material, conductors with a larger cross-sectional area have less resistance than conductors with a smaller cross-sectional area. American wire gauge (AWG) is used in the United States and other countries as a standard method of denoting wire diameter, especially for nonferrous, electrically conducting wire. ... In electricity, current refers to electric current, which is the flow of electric charge. ...


For bare conductors, the ultimate limit is the point at which power lost to resistance causes the conductor to melt. Aside from fuses, most conductors in the real world are operated far below this limit, however. For example, household wiring is usually insulated with PVC insulation that is only rated to operate to about 60 C, therefore, the current flowing in such wires must be limited so that it never heats the copper conductor above 60 C. Other, more expensive insulations such as Teflon or fiberglass may allow operation at much higher temperatures. 200 A Industrial fuse. ... Polyvinyl chloride (PVC) is a widely-used plastic. ... Teflon is the brand name of a polymer compound discovered by Roy J. Plunkett (1910–1994) of DuPont in 1938 and introduced as a commercial product in 1946. ... Fiberglass or fibreglass is material made from extremely fine fibers of glass. ...


The American wire gauge article contains a table showing allowable ampacities for a variety of copper wire sizes. American wire gauge (AWG) is used in the United States and other countries as a standard method of denoting wire diameter, especially for nonferrous, electrically conducting wire. ...


See also


  Results from FactBites:
 
Conductor (material) - Wikipedia, the free encyclopedia (753 words)
Electrically conductive materials are usually classified according to their electrical resistance; ranging from high to null resistance, there are semiconductors, ordinary metallic conductors (also called normal metals), and superconductors.
In United States, conductors are measured by American wire gauge for smaller ones, and circular mils for larger ones.
Conductors are usually surrounded by and/or supported by insulators and the insulation determines the maximum voltage that can be applied to any given conductor.
  More results at FactBites »

 
 

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