What do the coloured bands of the resistors mean?

Answer 1

They are a standard code with each individual colour representing a single whole number (1-10) indicating the resistance or ohm value.

Additionally the gold band represents 5% "tolerance" and the resistance value is more precise. The silver banded resistors have only 10% tolerance & therefore are not as precise in ohm value. Such should be cheaper to buy than the gold ones.

Answer 2

The bands on a resistor indicates it's ohmic value, tolerance and possibly temperature coefficient.

There are 3 types of color coded resistors, 4-band, 5-band and 6-band

On a 3 band resistor, the first 2 bands indicate the numeric ohm value of the resistor, the 3'rd band indicates the multiplier and the 4th band indicate tolerance.

For example:

Brown | Red | Orange | Gold| = 1 | 2 | 3 | 5%

This would mean that the resistance is 12 * 10^3 = 12,000 ohm +/- 5%

On a 5 band resistor it goes the same way, except that the first 3 values indicates ohmic value

For example:

Brown | Red | Orange | Yellow | Gold| = 1 | 2 | 3 | 4 | 5%

This would mean that the resistance is 123 * 10^4 = 1,230,000 ohm +/- 5%

6-band resistors work in the same way as 5-band, except that the 6th band indicates temperature coefficient, which tells how the resistors value changes as it heats up.

Answer 3

Internationally standards have been agreed as to what the colour bands mean. Therefore the presence and order of the colour bands is a visual statement as to the specification of the resistor. Tables of the meaning of the bands are widely published.