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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 ...
Electrical resistivity (also called volume resistivity or specific electrical resistance) is a fundamental specific property of a material that measures its electrical resistance or how strongly it resists electric current. A low resistivity indicates a material that readily allows electric current.
And for typical transmission lines, that are carefully built from wire with low loss resistance and small insulation leakage conductance ; further, used for high frequencies, the inductive reactance and the capacitive admittance will both be large, so the constant is very close to being a real number: .
Ohm's law states that the electric current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance, [1] one arrives at the three mathematical equations used to describe this relationship: [2]
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 ...
Parasitic resistance is a more general term, of which it is usually assumed that contact resistance is a major component. William Shockley [ 1 ] introduced the idea of a potential drop on an injection electrode to explain the difference between experimental results and the model of gradual channel approximation.
A typical low power potentiometer (see drawing) is constructed of a flat resistance element (B) of carbon composition, metal film, or conductive plastic, with a springy phosphor bronze wiper contact (C) which moves along the surface. An alternate construction is resistance wire wound on a form, with the wiper sliding axially along the coil. [14]
Each notch is stamped with a number, and the wire or sheet, which just fits a given notch, is stated to be of, say, No. 10, 11, 12, etc., of the wire gauge. The circular forms of wire gauge measurement devices are the most popular, and are generally 3 + 3 ⁄ 4 inches (95 mm) in diameter, with thirty-six notches; many have the decimal ...