Colour Code Of Carbon Resistances

Colour Code Of Carbon Resistances:

Carbon resistors consist of a high-grade ceramic rod or cone (called the substrate) on which a thin resistive film of carbon is deposited. They are commonly used in electrical equipment.

Colour Code:

The numerical value of carbon resistance is presented by colour code which consists of bands of different colours printed on it. commonly, the code consists of four bands, starting from left to right. The codes of different colours are given in the following table.
Interpretation Of Colour Bands:
1.      The first band indicates the first digit of the value of resistance.
2.      The second band gives the second digit.
3.      The third band is the decimal multiplier. It gives the number of zeros after the first two digits.
4.     The fourth band gives the tolerance value.
    
Tolerance:
The possible variation in the resistance of carbon resistor from marked value is called tolerance.
.  Silver band indicates the tolerance of 10%.
.  Golder band indicates the tolerance of 5%.
.  If there is no fourth band then the tolerance value is 20%.