To identify and select a resistor by its value resistor color coding is necessary. We find resistors in many applications in electrical, electronic and communication industries. Because resistors play a significant role in producing voltages drop and resisting the flow of currents. Hence they are key passive elements of electronics or electrical circuits. In order to achieve decided circuit parameters, the designer chooses the value of different resistors in the circuit. Moreover, the range of those resistance values is from a fraction of ohm to several mega ohms.
What is Resistor Color Coding?
The color coding means branding the resistor with specific nos of colored bands. Here, each band signifies a specific value. To clarify, these values identify the first digit, second digit, third digit, multiplier, tolerance and temperature coefficient of resistance.
In which resistors we use color codings?
There are various types of resistor available, two main types are
- Linear Resistors
- Non-Linear Resistors
Subtypes of linear resistors make use of color coding scheme. For example, the common linear resistors which contain color codes are Carbon Resistor, Cermet Film Resistor, Carbon Film Resistor, Thin Film Resistor.
The position of each color band defines the significance of the value of that color. We read these bands from left to the right. Here the leftmost is being the band nearest to the connecting wire of the resistor. Such as from left each of the first two or three bands indicates a single digit. Then the next right band indicates the multiplier. Then next right band represents the tolerance etc.
Resistor Color Code Table
Color Codes are as follows
Types of Resistor Color Coding
Types of Resistor Color Coding are
- 3 Band Color Coding
- 4 Band Color Coding
- 5 Band Color Coding
Three Band Color Coding of Resistors
These resistors contain only three color bands. In short, we define these three color bands as
For example, say the band has three colors as Blue Violet Green.
Since the tolerance band is absent, we assume the tolerance being ±20%. The resistance value according to resistor color code will be as
50×101 ±20% 500 Ω
50 X 101 ± (20% of 500) Ω
i.e. (500 – 100) Ω to (500 + 100) Ω i.e. 400 to 600 Ω
Four Band Color Coding of Resistors
These resistors contain four color bands. In short, we define the position of the color bands as
For example let the resistor has four bands, Orange Green Brown Silver
The value according to color code will be
35 X 101 ± (10% of 350) Ω
i.e. (350 – 35) Ω to (350 + 35) Ω i.e. 315 to 385 Ω
Five Band Color Coding of Resistors
These resistors contain five color bands. And we define the color bands as
For example, let the resistor shows five colors as Yellow Blue Red Brown Gold
The value according to color code will be
462 X 101 ± 5%
i.e. (4620 – 231) Ω to (4620 + 231) Ω i.e. 4389 Ω to 4851 Ω.
6 Band Resistor Color Coding
There are six color bands on some resistors. So, we call them as six band resistors. There are four color bands close to each other. Also, this group of bands is close to one of the resistor terminals. Besides these, there are other two bands a little bit away from those four bands. In order to read the color code, we keep the resistor in a correct orientation. For this reason, we keep the group of four closed bands to the left as shown below.
In a six-band resistor, the left three bands tell us the digits of the resistance value. From left, the fourth band represents the multiplier. Then the tolerance band comes. Lastly, the rightmost band tells the temperature coefficient of resistance in ppm per degree centigrade.
The 7th column of the following table shows the values of the temperature coefficient for different colors.
Let us take a 6 band resistor. We have shown it as below.
Here, the leftmost color is orange. Hence, the first significant digit of the resistance value is three.
The second color is red. Hence, the second significant digit of the resistance value is two.
The third color is green. Hence, the third significant digit of the resistance value is five.
The fourth band is black, hence the multiplier is one. Then the fifth band is brown, so the tolerance is ±1%. Lastly, the rightmost color is blue. Thus the temperature coefficient of resistance is 10 ppm/K.
325×1±1 Ω at 100 ppm/K or 325 ±1 Ω at 100 ppm/K
- Resistance Definition and Units of Electrical Resistance
- Resistivity and Laws of Resistance and Unit of Resistivity
- Conductance and Conductivity
- Resistances in Series
- Parallel Combination of Resistances or Parallel Resistances
- Types of Resistor
- Resistor Color Coding 3, 4, 5 Band Resistor Color Coding