Resistance is a measure of the opposition to current flow in an electrical circuit. Resistance is measured in ohms, symbolized by the Greek letter omega (Ω). Ohms are named after George Simon Ohm (1784-1854), a German physicist who studied the relationship between voltage, current and resistance. He is credited for formulating Ohm’s Law. The electrical resistance of a circuit component or device is defined as the ratio of the voltage applied to the electric current which flows through it. The higher the resistance, the lower the current flow and vice-versa. resistivity : The electrical resistance per unit length, area, or volume of a substance is known as resistivity. Table of resistivity Material Resistivity ρ (ohm m) Temperature coefficient α per degree C Conductivity σ x 10 7 /Ωm Ref Silver 1.59 x10 -8 .0038 6.29 3 Copper 1.68 x10 -8 .00386 5.95 3 Copper, annealed 1.72 x10 -8 .00393 5.81 2 Aluminum 2.65 x10 -8 .00429 3.77 1 Tungsten 5.6 x10 -8 .0045 1.79 1 Iron 9.71 x10 -8 .00651...
[…] that the maximum amount of power will be dissipated by a load resistance if it is equal to the Thevenin or Norton resistance of the network supplying power. The Maximum Power Transfer Theorem does not satisfy the […]
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