Resistor Values
How to read resistor values
Resistor values are marked using colored bands, according to a code developed in the 1920s, when it was too difficult to write numbers on such tiny objects. Each color corresponds to a number. Each resistor has either 4 or 5 bands. In the 4-band type, the first two bands indicate the first two digits of the value while the third one indicates the number of zeroes that follow(technically it represents the power of ten). The last band specifies the tolerance.
Color Codes
A 4 band resistor is a resistor that has only 4 colors on it and a 5 band resistor is a resistor that has 5 colors on it. In the first part, if your resistor has 4 colors you will only need to keep track of the first 3 colors for now. If it has 5 colors, you will need to keep track of 4 for now. Here are the numbers that correspond with each color. Now, you will need to write down the numbers that go with each color on your resistor (in order.) Black=0, brown=1, red=2, orange=3, yellow=4, green=5, blue=6, purple=7, gray=8, and white=9. With the first 2-3 numbers you’ve written down, (2 if your resistor has 4 colors and 3 if your resistor has 5,) keep them in order. Now, with the next number, multiply 10 to the power of the number that corresponds to the color. Now, you’ve finished learning how to read the resistance on a resistor!
Do you want to know the tolerance of your resistor? Now based on the last color you wrote down, here are the corresponding numbers. Brown=1% red= 2% gold=5% and silver=10%. Remember that the last number shouldn’t be counted in the resistor value, but the tolerance percentage.
Example
Ok so, right here I have a 5 band resistor and a 4 band resistor. The 5 band resistor is a 10k resistor and the 4 band resistor is 4.7k resistor. We know that this resistor is a 10k(5 band-blue) resistor because of the colors on it. We can observe that the colors on it are: brown, black, black, red, and the tolerance color is brown. The same process goes for the other resistor. We can observe that the colors on the 4.7k resistor are: yellow, purple, red, and the tolerance color is gold.