Category Archives: Electronics

Resistance Colour Coding calculation

Resistors

Example:       Circuit symbol:   

Function

Resistors restrict the flow of electric current, for example a resistor is placed in series with a light-emitting diode (LED) to limit the current passing through the LED.

Connecting and soldering

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Resistivity Calculation

Resistivity Calculation – The electrical resistance of a wire would be expected to be greater for a longer wire, less for a wire of larger cross sectional area, and would be expected to depend upon the material out of which the wire is made (resistivity). Experimentally, the dependence upon these properties is a straightforward one for a wide range of conditions, and the resistance of a wire can be expressed as

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Resistance and Conductance

Resistance and Conductance

Resistance

The electrical resistance of a circuit component or device is defined as the ratio of the voltage applied to the electric current whichflows through it:

 

If the resistance is constant over a considerable range of voltage, then Ohm's law,

I = V/R, can be used to predict the behavior of the material. Although the definition above involves DC current and voltage, the same definition holds for the AC application of resistors.

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