Explain the concept of colour code for carbon resistors.

Explanation

Color code for carbon resistors: Carbon resistors consists of a cermic core, on which a thin layer of crystalline carbon is deposited. These resistors are inexpensive, stable and compact in size. Color rings are used to incicate the value of the resistance according to the rules.
Three coloured rings are used to indicate the values of a resistor: the first two rings are significant figures of resistances, the third ring indicates the decimal multiplier after them. The fourth color, silver or gold, shows the tolerance of the resistor at 10% or 5%. If there is no fourth ring, the tolerance is 20%. For the resistor, the first digit = 5 (green), the second digit = 6 (blue), decimal multiplier = `10^(3)` (orange) and tolerance = `5%` (gold). The value of resistance `=56xx10^(3)Omega` or `56k Omega` with the tolerance value `5%`.