Resistor Colour Code

Posted on Friday, 5 August 2011 by Matal Hawa

Resistor Color Code:
The value of a resistor’s resistance is indicated on its body by a color band.  This band indicates the resistance with percentage of tolerance.
Using color code gives reliability of resistance calculation and enhances look of the resistor. It is also called the “Color Band”. The color band on a resistors body looks like below:



                                                   Figure: 1



You can see there are four coloured lines on the body of the resistor. Look at the picture below to see which band means what.
                                                           Figure: 2

So the first band means a simple integer number which is the first digit of the number of ohomic resistance. The second band means also another integer which is the second digit of the number of ohomic resistance. Third one is the multiplier of the number. And the last one is the tolerance which is usually silver or gold coloured.
The value of the colours in the band is given below:


To remember the colour code I would like to give you a tremendous way. That is remembering this word “BB ROY Good Boy Very Good Worker” which means:
B = Black
B = Brown
R = Red
O = Orange
Y = Yellow
Good = Green
Boy = Blue
Very = Violet
Good = Gray
Worker = White
 Now to find the value of the resistance of the resistor at figure 2 calculate like this:
A = First band = Red = 2
B = Second Band = Violet = 7
C = Third band (multiplier) = Green = 5
D = Tolerance = Gold = +/- 5%
Hence, The value of the resistance = (AB)*10C +/-D = (27*100000)+/-5%
                                                                = 2700000 +/- 5% Ohm

Sometime it is very confusing from which side you should start counting the first digit. The correct procedure in this case is to start with the opposite side where tolerance bands (silver of gold) are drawn.

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