# Resistor colour coding | lab work

This article contains Resistor colour coding experiment. Lab Work.  There are 5 given resistors as sample & we need to find its value, by reading colour bands on it.

## Resistor colour coding

#### Objective

1. To learn resistor colour coding.
2. To determine the stated value of a resistor by interpreting the colour code indicated on the resistor.

#### Apparatus Required

The Apparatus required for resistor colour coding are –

1. Carbon resistor ( Sample )
2. Digital Multi meter

### Theory

There are two ways to find the resistor value. The colour bands on the body of resistor tell how much resistance it has. As shown in the following diagram figure. There are 5 band resistor and 4 band resistor. From both five and four band resistor, the last band indicates tolerance. Even if the values are printed, the letters will be so small that it would be difficult to read them by naked eyes. Therefore, the colour bands are printed on the resistor. This system of representing the value of resistor is known is colour coding.

## Resistor Colour Coding Table

 The Colour band sequence Colour 1st band 2nd band Multiplier tolerance Black 0 0 0 _ Brown 1 1 10 _ Red 2 2 102 _ Orange 3 3 103 _ Yellow 4 4 104 _ Green 5 5 105 _ Blue 6 6 106 _ Violet 7 7 107 _ Grey 8 8 108 _ White 9 9 109 _ Gold – – ± 5% Silver – – ± 10% No Colour – – ± 20%

#### Procedure

Procedure for Resistor colour coding.

1. Axial resistors are cylindrical and have leads extending from each end.
2. Look at the resistor so the  group of three or four  colour band  are on the  left side.
3. Read the bands colour from left to right.
4. The value of resistor colour code system is recorded.
5. In other way, the central Knob of digital multimeter is adjusted to get the appropriate measurement value.
6. The value of resistor shown in digital multimeter is recorded.

#### Calculation

Analysed Data for given sample resistors  is noted below –

1. First resistor
 Band colour Significant digit 1st band Green 5 2nd band Blue 6 Multiplier Red 102 Tolerance Gold ± 5 %

Theoretical value

= 56 X  ± 5 % Ω = 5600 ± 5 % Ω

= 5.6 kΩ ± 5 %

 Upper value Lower value 5600 + 5600 * 5 / 100 5600 – 5600 * 5 / 100 5880 Ω = 5.880 kΩ 5320 = 5.320 kΩ

Practical Value = 5.57 kΩ ( Verified using multi meter )

1. Second Resistor
 Band Colour Significant digit 1st   band Brown 1 2nd   band Green 5 Multiplier Red 102 Tolerance Gold ± 5 %

Theoretical value

= 15 * Ω ± 5% = 1500 Ω ± 5 %

= 1.5 kΩ ± 5 %

 Lower value Upper value 1500 – 1500 * 5 / 100 1500 + 1500 * 5 / 100 1425 Ω 1575 Ω 1.425 Ω 1.575 kΩ

Practical Value = 1.46 kΩ ( measured using multi meter )

1. Third resistor
 Band Colour Significant digit 1st band Red 2 2nd band Red 2 Multiplier Brown 10 Tolerance Gold ±5%

Theoretical Value

= 22 * 10 Ω ± 5 % = 220 Ω ± 5 %

= 0.22 kΩ ± 5 %

 Upper value Lower value 220 + 220 * 5 / 100 220 – 220 * 5 / 100 ( 220 + 11 ) Ω ( 220 – 11 ) Ω 231 Ω 209 Ω

Practical value = 215 Ω ( measured using multi meter )

1. Fourth Resistor
 Band Colour Significant digit 1st band Yellow 4 2nd band Blue 6 Multiplier Orange Tolerance Gold ± 5 %

Theoretical value

= 46 * Ω ± 5 % = 4600 Ω ± 5 %

= 46 kΩ ± 5 %

 Upper value Lower value 46000 + 46000 * 5 / 100 46000 – 46000 * 5 / 100 46000 + 2300 46000 – 2300 Ω 48300 Ω = 48.3 kΩ 43700 = 43.7 kΩ

Practical Value = 47.1 kΩ ( measured using multi meter )

1. 5th resistor
 Band Colour Significant digit 1st band Brown 1 2nd band Green 5 Multiplier Orange Tolerance Gold ±5%

Theoretical Value

= 15 *  Ω ± 5 % = 15000 Ω ± 5 %

= 15 kΩ ± 5 %

 Upper value Lower value 15000 + 15000 * 5 / 100 15000 – 15000 * 5 / 100 15000 + 750 15000 – 750 Ω 15750 Ω = 15.750 kΩ 14250 = 14.250 kΩ

Practical value = 14.20 kΩ ( measured using multi meter )

### Observation Table

 1st 2nd 3rd total T V kΩ L V U V P V Green 5 Blue 6 Red Gold ±5% 5.6 kΩ 5.32 kΩ 5.88 kΩ 5.57 kΩ Brown 1 Green 5 Red Gold ±5% 1.5 kΩ 1.5 kΩ 1.425 kΩ 1.46 kΩ Red 2 Red 2 Brown Gold ±5% 220 Ω 209 Ω 231 Ω 215 Ω Yellow 4 Blue 6 Orange Gold ±5% 46 kΩ 43.7 kΩ 48.3 kΩ 47.1 kΩ Brown 1 Green 5 Orange Gold ±5% 15 kΩ 14.25 kΩ 15.75 kΩ 14.30 kΩ

#### Conclusion

As a conclusion, the resistor colour code was very useful in determining the value of individual resistor, The represented data in the table indicate that all the resistor selected were within the tolerance range specified by the colour code. The value of resistor from digital multi meter got matched by the manual calculation using colour code.

Author

Akash Sharma

Discover More –