Unformatted text preview: nd Systems G is the reciprocal of resistance, and is called the conductance of the conductor. It has units of Mho (ohm in reverse order). Resistivity of common materials at room temperature Material Resistivity (Ohm‐meter) Aluminium 2.733 x 10‐8 Copper 1.725 x 10‐8 Gold 2.271x10‐8 Iron 9.98x10‐8 Nickel 7.20x10‐8 Platinum 10.8x10‐8 Carbon 3.5x10‐8 Difference between resistor and resistance Resistor is an electrical element made up of conducting material and resistance is the property of this element where the voltage is proportional to the current. Resistor color code Color bands are placed on commonly used resistors which can be used for inferring their values. The first three bands closest to one end of the resistors are used to determine the resistance. The first two bands represent the numerical value of the resistor and third band represents the power‐of‐10 multiplier. The fourth band represents the tolerance of the resistor (gold‐5%, silver‐10% and plain‐
20%). Resistance value = (b...
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This document was uploaded on 01/20/2014.
 Winter '14

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