Colour code of carbon resistors|Electricity

(9) Colour code of carbon resistors

  • Commercially resistors of different type and values are avilable in the market but in electronic circuits carbon resistors are more frequently used
  • In carbon resistors value of resistance is indicated by four coloured bands marked on its surface as shown below in figure

    Colour code of carbon resistors|Electricity

  • The first three bands a,b.c determine the value of the resistance and fourth band d gives the tolerance of the resistance
  • The colour of the first and second band respectively gives the first and second significant figure of the resistance and third band c gives the power of the ten by which two significant digits are multiplied for obtainng the value of the resistance
  • value of different colurs for making bands in carbon resistors are given below in the table

    Colur Figure(first and second band) Multiplier(for third band) tolerance
    Black 0 1 -
    Brown 1 10 -
    Red 2 102 -
    Orange 3 103 -
    Yellow 4 104 -
    Green 5 105 -
    Blue 6 106 -
    Violet 7 107 -
    Gray 8 108 -
    white 9 109 -
    Gold - 10-1 5%
    Silver - 10-2 10%
    no Colour - - 20%

  • For example in a given resistor let first strip be brown ,second strip be red and third be orange and fourth be gold then resitance of the resitor would be
    12X 103 +/- 5%

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