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Colour coding and standard resistor values

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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.