Search results
Results from the WOW.Com Content Network
Sometime around 1913 several copper samples from 14 important refiners and wire manufacturers were analyzed by the U.S. Bureau of Standards. The average resistance of the samples was determined to be 0.15292 Ω for copper wires with a mass of 1 gram of uniform cross section and 1 meter in length at 20 °C. In the United States this is usually ...
At high temperatures, the resistance of a metal increases linearly with temperature. As the temperature of a metal is reduced, the temperature dependence of resistivity follows a power law function of temperature. Mathematically the temperature dependence of the resistivity ρ of a metal can be approximated through the Bloch–Grüneisen ...
For wire sizes smaller than AWG No. 2 (33.6 mm 2, 0.0521 sq in), this term is also generally regarded as insignificant. R c , a {\textstyle R_{c,a}} is the effective thermal resistance between the conductor and the ambient conditions, which can require significant empirical or theoretical effort to estimate.
Copper has a very linear resistance–temperature relationship; however, copper oxidizes at moderate temperatures and cannot be used over 150 °C (302 °F). [citation needed] The significant characteristic of metals used as resistive elements is the linear approximation of the resistance versus temperature relationship between 0 and 100 °C.
Errata: The numbered references in the NSRDS-NBS-8 pdf are found near the end of the TPRC Data Book Volume 2 and not somewhere in Volume 3 like it says. [32] Aluminium oxide, porous 22% Porosity 2.3 [45] Constant 1000-1773 [45] This is number 54 on pages 73 and 76. Shakhtin, D.M. and Vishnevskii, I.I., 1957, interval 893-1773 Kelvins. [45 ...
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 ...
Discover the best free online games at AOL.com - Play board, card, casino, puzzle and many more online games while chatting with others in real-time.
Joule heating (also known as resistive, resistance, or Ohmic heating) is the process by which the passage of an electric current through a conductor produces heat.. Joule's first law (also just Joule's law), also known in countries of the former USSR as the Joule–Lenz law, [1] states that the power of heating generated by an electrical conductor equals the product of its resistance and the ...