Function Resistors restrict the flow of electric current, for example a resistor is placed in series with a light-emitting diode (LED) to limit the current passing through the LED. Connecting and soldering Resistors may be connected either way round. They are not damaged by heat when soldering. The Resistor Colour Code Colour Number Black 0 Brown 1 Red 2 Orange 3 Yellow 4 Green 5 Blue 6 Violet 7 Grey 8 White 9 Resistor values - the resistor colour code Resistance is measured in ohms, the symbol for ohm is an omega . 1 is quite small so resistor values are often given in k and M . 1 k = 1000 1 M = 1000000 . Resistor values are normally shown using coloured bands. Each colour represents a number as shown in the table. Most resistors have 4 bands: The first band gives the first digit . The second band gives the second digit . The third band indicat...