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Colour coding and standard resistor values

Lektion Progression

Colour coding and standard resistor values

Conventional fixed resistors have coloured bands showing their value. These can be decoded using Table 3. For example, a resistor with four bands where the coding is yellow (4), violet (7), red (× 100) and brown (1%) has a resistance of

 (47 Ω × 100) ± 1% = 4700 Ω ± 47 Ω

There is a similar five-band scheme where there are three instead of two digits in the resistance value, and a six-band scheme that also gives temperature information. Sometimes it can be hard to see these colour values on the resistors and a multimeter is used to check them.