Search results
Results From The WOW.Com Content Network
The main grade of copper used for electrical applications, such as building wire, motor windings, cables and busbars, is electrolytic-tough pitch (ETP) copper (CW004A or ASTM designation C100140). If high conductivity copper must be welded or brazed or used in a reducing atmosphere, then oxygen-free high conductivity copper (CW008A or ASTM ...
Revised standards for wire materials and wiring devices (such as the CO/ALR "copper-aluminium-revised" designation) were developed to reduce these problems. While larger sizes are still used to feed power to electrical panels and large devices, aluminium wiring for residential use has acquired a poor reputation and has fallen out of favour.
It represents a material's ability to conduct electric current. It is commonly signified by the Greek letter σ , but κ (especially in electrical engineering) [citation needed] and γ [citation needed] are sometimes used. The SI unit of electrical conductivity is siemens per metre (S/m).
Long-distance electromagnetic telegraph systems from 1820 onwards [a] used two or more wires to carry the signal and return currents. It was discovered by German scientist C.A. von Steinheil in 1836–1837, that the ground could be used as the return path to complete the circuit, making the return wire unnecessary. [2]
A special form of water ice, superionic water, has been shown to conduct much more efficiently than normal water ice. [ 3 ] Solid-phase proton conduction was first suggested by Alfred Rene Jean Paul Ubbelohde and S. E. Rogers. in 1950, [ 4 ] although electrolyte proton currents have been recognized since 1806.
Also called chordal or DC resistance This corresponds to the usual definition of resistance; the voltage divided by the current R s t a t i c = V I. {\displaystyle R_{\mathrm {static} }={V \over I}.} It is the slope of the line (chord) from the origin through the point on the curve. Static resistance determines the power dissipation in an electrical component. Points on the current–voltage ...
A wire is a flexible, round bar of metal. Wires are commonly formed by drawing the metal through a hole in a die or draw plate. Wire gauges come in various standard sizes, as expressed in terms of a gauge number or cross-sectional area. Wires are used to bear mechanical loads, often in the form of wire rope.
The wire is coated with a range of polymeric insulations, including varnish, rather than the thicker plastic or other types of insulation commonly used on electrical wire. [5] High-purity oxygen-free copper grades are used for high-temperature applications in reducing atmospheres or in motors or generators cooled by hydrogen gas.