Color ring resistance identification method - Database & Sql Blog Articles

red

red

black

gold

2

2

0 0

±5%

The resistance is: 22Ω and not 220Ω!

When reading resistor color codes, the fourth band represents the tolerance. Gold and silver are common colors for this band, with gold indicating a 5% tolerance and silver indicating 10%. But what about the third band? It's used to indicate the number of zeros to add to the first two digits. However, if the third band is gold or silver, it actually tells you to move the decimal point instead of adding zeros.

Here's how it works:

- If the third band is gold, move the decimal point one place to the left.

- If the third band is silver, move the decimal point two places to the left.

Let's look at some examples:

1. Color code: Orange, Gray, Gold

This translates to 3.9Ω (since the gold moves the decimal one place left).

2. Color code: Green, Yellow, Silver, Gold

This gives 0.54Ω (silver moves the decimal two places left, and gold is the tolerance).

Resistors with such low values are rarely used in general circuits, so they are uncommon in typical resistor series. Understanding these rules can help avoid confusion when working with small-value resistors or precision components.