DEPARTMENT OF TECHNICAL EDUCATION

ANDHRA PRADESH
Name : P.S.R.Muralidhar
Designation : Sr. Lecturer in ECE
Institution : GMR. Polytechnic, Gajwel, Medak Dist.
Course : Electronics & Communication Engg.
Year/Semester : I Year
Subject : Electronic Components & Devices
Subject Code : EC-105
Major Topic : Resistors
Sub Topic : Colour coding of Resistors - I
Duration : 100 Minutes
Teaching aids : PPT’s

EC105. 5 to 6 1
Objectives

On completion of this class you should be

able to know

• The colour coding of Resistors.

• How to compute the value of Resistance using the

colour code.

EC105. 5 to 6 2
 Colour Coding of Resistors

How the Resistance value is indicate on the Resistors?

• By printing its value on the body (for large size Resistors).

• By indicating its value with a colour code (usual case).

EC105. 5 to 6 3
Colour Coding of Resistors

What is Colour Coding of Resistors?

• A process through which different colour bands or

rings are used to indicate the value of Resistance.

EC105. 5 to 6 4
Colour Coding of Resistors

What these colours indicate?

• They indicate Resistance value and also

Tolerance value.

EC105. 5 to 6 5
How many colour bands appear?

• Usually 3 to 4 colour bands are printed on the body with

each colour having a value.

• They appear differently on axial and radial Resistors.

EC105. 5 to 6 6
 RESISTOR COLOR CODES

Colour Coding of Resistors

Color 1st Digit (A) 2nd Digit (B) Multiplier (C) Tolerance (D)

Black 0 0 1 --

Brown 1 1 10 1%

Red 2 2 100 2%

Orange 3 3 1,000 3%

Yellow 4 4 10,000 4%

Green 5 5 100,000 --

Blue 6 6 1,000,000 --

Violet 7 7 10,000,000 --

Gray 8 8 100,000,000 --

White 9 9 109 --

Gold -- -- 0.1 (EIA) --

Silver -- -- 0.01 (EIA) --

No Color -- -- -- 20%
EC105. 5 to 6 7
 Axial Lead Resistor

Colour coding on Axial Resistors

• Four (4) colour rings appear on the body of axial
resistors.

• Colour rings A,B,C indicate value of Resistance.

• Colour ring D indicates Tolerance value.

EC105. 5 to 6 8
Colour coding on Radial Resistors

Four (4) colours appear on the body

Radial Lead Radial Lead

Dot Band

A– Colour of the Resistor body.

B– a colour dot.

C,D – 2 colour bands at the two ends.

EC105. 5 to 6 9
Table for Resistor Colour Codes

Colour Value Multiplier

Black 0 10° =1
Brown 1 10¹ =10
Red 2 10²
Orange 3 10³
Yellow 4 104
Green 5 105
Blue 6 106
Violet 7 107
Grey 8 108
White 9 109
Gold - 0.1
Silver - 0.01

Table 1

EC105. 5 to 6 10
How to compute Resistance value?

1st Colour band or ring on the body

• Indicates first digit of the Resistance value.

2nd Colour band or ring on the body

• Indicates second digit of Resistance value.

EC105. 5 to 6 11
How to compute Resistance value?

3rd colour band or ring indicates.

• Multiplier or the no. of zeroes after the first 2 digits.

4th colour band or ring indicates.

• Tolerance percentage.

EC105. 5 to 6 12
Finding the Resistance value

• For the following colour sequence, find the

Resistance value along with Tolerance.

Brown, Black, Red, Gold

We know that the value of

Brown = 1, Black = 0, Red = 2, Gold = 5%

EC105. 5 to 6 13
Finding Resistance value

The Resistance value is computed as

First Digit - 1

Second Digit - 0

Multiplier - 2 zeros after the 2nd Digit

So, the Resistance value is 1000 Ω

EC105. 5 to 6 14
Finding Resistance value

The Tolerance percentage is 5%

Rated value = 1000 Ω, 5% of it is 50 Ω

So Tolerance = 50 Ω

So the Resistance value will be in the range of

(1000 – 50) Ω to (1000 + 50) Ω,

i.e. from 950 Ω to 1050 Ω

EC105. 5 to 6 15
Another Example
• Find the Resistance and Tolerance values for the
colour sequence

Brown, Gray, Orange, Silver

Brown –1, Gray – 8,Orange – 3, Silver- 10%

Resistance value = 18000 Ω

Tolerance = 10% of 18000 Ω = 1800 Ω

So the Resistance range =16200 to 19800 Ω

EC105. 5 to 6 16
Another Example
• Find the Resistance and Tolerance values for the colour
sequence

Red, Red, Red, No Colour

Red = 2

So the Resistance value is 2200 Ω

Tolerance (20%) = 440 Ω

So the Resistance range is 1760Ω to2640Ω

EC105. 5 to 6 17
Another Example
• Find the Resistance and Tolerance values for the colour
sequence

Yellow, Violet, Gold, Gold

Yellow=4, Violet=7, Gold=0.1, Gold=5%

Resistance value = 47 x 0.1 = 4.7 Ω

Tolerance (5%) = 0.235 Ω

So, the Resistance = 4.465 Ω to 4.935 Ω

EC105. 5 to 6 18
To know the Colour code from the Given
Resistance value
Give the colour code for the following Resistance value

1 MΩ ± 10%

1 MΩ can be written as 10 x 105

So colours are Brown, Black, Green

Colour for 10% Tolerance is Silver

EC105. 5 to 6 19
Another Example
Give the colour code for the following
Resistance value

4.7KΩ ± 5%

4.7KΩ can be written as 47 x 102 Ω

So the colours are Yellow, Violet, Red

Colour for 5% Tolerance is Gold

EC105. 5 to 6 20
Another Example

Give the colour code for the following Resistance value

68KΩ ± 20%

The colours are Blue, Gray, Orange

Colour for 20% Tolerance is No colour

EC105. 5 to 6 21
 Five band resistor colour code
1 2 3 4 5
band

Color Digit Digit Digit Multiplier Tolerance

Black 0 0 0 x 1 ohms

Brown 1 1 1 x 10 ohms 1 1% (F)

Red 2 2 2 x 100 ohms 1 2% (G)

Orange 3 3 3 x 1K ohms

Yellow 4 4 4 x 10K ohms

Green 5 5 5 x 100K ohms 1 0.5% (D)

Blue 6 6 6 x 1M ohms 1 0.25% (C)

Violet 7 7 7 x 10M ohms 1 0.10% (B)

Grey 8 8 8 1 0.05%

White 9 9 9

Gold x 0.1 ohms 1 5% (J)

Silver x 0.01 ohms 1 10% (K)

EC105. 5 to 6 22
Summary

• The value of resistance is indicated in

Two ways

1. By printing its value

2. By using a colour code

• The axial and radial Resistors are coloured

differently.

EC105. 5 to 6 23
Summary

• Each colour has a predefined value

• By looking at the colours printed on the body of

the Resistor, we can know the Resistance value.

EC105. 5 to 6 24
Summary

• The last colour on the Resistor body indicates the

Tolerance Percentage.

• Different values of Resistors are available in different

Tolerance ranges.

EC105. 5 to 6 25
 Quiz
1.Give the value for colour code of red,
red, red,silver bands of a resistor
(a)220ohms,10%
(b)2200 ohms,5%
(c) 2200 ohms,10%
(d) 22 ohms ,10%

EC105. 5 to 6 26
 Frequently Asked Questions

2. List the ways in which Resistance value is indicated

on Resistors ?

6. How the Colour coding is done on the axial and radial

resistors ?

EC105. 5 to 6 27
 Frequently Asked Questions

1. Give the values of various colours used in colour

coding of Resistors.

4. Find the value of the Resistance for the following

Colour code.

White, Black, Blue, Gold

EC105. 5 to 6 28
 Frequently Asked Questions

5. Find the value of the Resistance for the following

Colour code

Gray, Red, Silver, Silver

6. Find the colour code for the Resistance value

33Ω ± 5%

EC105. 5 to 6 29
 Frequently Asked Questions

2. Find the colour code for the Resistance value

1.8MΩ ± 10%

8. Find the colour code for the Resistance value

15KΩ ± 20%

EC105. 5 to 6 30