How to find the resistance of a resistor using color code
Resistors are passive components that are used to limit or control the flow of electrical current in electronic circuits. They are widely used in various electronic devices such as radios, televisions, computers, and cellphones, to name a few. The resistance resistor color code value of a resistor is indicated by a color code that is printed on its surface. In this article, we will discuss how to find the resistance of a resistor using the color code.
The color code consists of a set of colored bands
that are printed on the surface of the resistor. Each color represents a digit or a multiplier, and the combination of colors provides the resistance value of the resistor. There are typically four or five color bands on a resistor, depending on its tolerance value.
The color bands on a resistor are read from left to right, and each band represents a specific value or digit. The first band represents the first digit of the resistance value, the second band represents the second digit, the third band represents the multiplier, and the fourth band (if present) represents the tolerance value.
To determine the resistance value of a resistor using the color code, follow these steps:
Step 1: Identify the color of the first band and determine its corresponding digit value using the following color chart:
Black – 0
Brown – 1
Red – 2
Orange – 3
Yellow – 4
Green – 5
Blue – 6
Violet – 7
Gray – 8
White – 9
For example, if the first band is red, its corresponding digit value is 2.
Step 2: Identify the color of the second band and determine its corresponding digit value using the color chart.
For example, if the second band is brown, its corresponding digit value is 1.
Step 3: Identify the color of the third band and determine its corresponding multiplier value using the following color chart:
Black – x1
Brown – x10
Red – x100
Orange – x1,000
Yellow – x10,000
Green – x100,000
Blue – x1,000,000
Violet – x10,000,000
Gray – x100,000,000
White – x1,000,000,000
For example, if the third band is orange, its corresponding multiplier value is x1,000.
Step 4: Calculate the resistance value of the resistor using the formula:
Resistance = (Digit 1 * 10 + Digit 2) * Multiplier
For example, if the first band is red (digit value = 2), the second band is brown (digit value = 1), and the third band is orange (multiplier value = x1,000), the resistance value of the resistor is:
Resistance = (2 * 10 + 1) * 1,000
Resistance = 21,000 ohms (or 21kΩ)
Step 5 (optional): If the resistor has a fourth band, identify its color and determine its corresponding tolerance value using the following color chart:
Brown – ±1%
Red – ±2%
Green – ±0.5%
Blue – ±0.25%
Violet – ±0.1%
Gray – ±0.05%
Gold – ±5%
Silver – ±10%
For example, if the fourth band is brown, the tolerance value of the resistor is ±1%.
Final words
determining the resistance value of a resistor using the color code is a simple and straightforward process. By identifying the color of each band and using the Mad PCB appropriate color chart, you can quickly calculate the resistance value of a resistor and use it in your electronic circuits.
