Resistors 

By on

Resistors
Resistors
Resistors are electronic components that oppose the flow of current. Manufactured in various types and ranges they have a wide application to electronics.

The relationship between voltage and current in a resistor is given by Ohm's Law:

 myElectrical Equation

 

Identification and Values

Colour Code

When inspecting resistors, the given value is either printed on the body is can be determined from the resistor colour code.

Resistor Colour Code
Example

ResistorCode

Red(2)Blue(6)Green(5)
=2600000
=2.6 MΩ

The first two bands are the value and the third band is a decimal multiplier (10x).

Black Brown Red Orange Yellow Green Blue Violet Grey White

0

1

2

3

4

5

6

7

8

9

 

 

The fourth band give the tolerance:

Gold Silver None

5%

10%

20%

For precision resistors, sometimes a five band colour coding is used – first three bands are the value, fourth band is the multiplier and the fifth band is the tolerance.

Preferred Values

Resistors are manufactured and specified in a range of preferred values. 

The table shows the range of preferred values:

10 12 15 18 22 27 33 39 47 56 68 82

Note: to obtain full range, multiply table by 10X

Circuit Arrangements

For more information on circuit arrangements and how to work these out, please see the following note:



Steven McFadyen's avatar Steven McFadyen

Steven has over twenty five years experience working on some of the largest construction projects. He has a deep technical understanding of electrical engineering and is keen to share this knowledge. About the author

myElectrical Engineering

comments powered by Disqus

  1. resistor's avatar resistor says:
    8/7/2012 7:58 PM

    There also exist 6 band resistors, where the 6th band often refers to the thermal coefficient. for more information on resistor color codes http://www.resistorguide.com/resistor-color-code

    • Steven's avatar Steven says:
      8/8/2012 12:59 PM

      Thanks for the information on the sixth band. Your site all about resistors is interesting; good luck with it.


Comments are closed for this post:
  • have a question or need help, please use our Questions Section
  • spotted an error or have additional info that you think should be in this post, feel free to Contact Us



What is a rectifier transformer?

I've recently come across this question a couple times browsing the internet. Decided to give a quick answer here. A rectifier transformer is a transformer...

Closed Doors

"I can live with doubt and uncertainty and not knowing. I think it is much more interesting to live not knowing than to have answers that might be wrong...

Lighting - Lamps

Lamps are the essential part of any luminaire. These are the light generating components. Since the advent of electrical lighting in the middle of the...

How to refer fault levels across a transformer

Over the past year or so I've been involved in on going discussions related to referring fault levels from the secondary of a transformer to the primary...

Michael Faraday (the father of electrical engineering)

Famed English chemist and physicist Michael Faraday was born on September 22, 1791, in Newington Butts, a suburb of Surrey just south of the London Bridge...

Robotics - Home Innovations

We have a sister note to this (Robots - Interesting Video), in which I have posted some videos of interesting robots developed by commercial corporations...

Why is electricity so hard to understand?

It's been a busy few months on different projects or busy couple of decades depending on how I look at it. I can say that on the odd (frequent) occasion...

Back to Basics - Ohm’s Law

Electrical engineering has a multitude of laws and theorems. It is fair to say the Ohm's Law is one of the more widely known; it not the most known. Developed...

Network Theory – Introduction and Review

In electrical engineering, Network Theory is the study of how to solve circuit problems. By analyzing circuits, the engineer looks to determine the various...

1,000 kV UHV First for China

At the beginning of the year China put the world's first 1,000 kV UHV transmission system into operation. Transmitting power at over a million volts is...

Have some knowledge to share

If you have some expert knowledge or experience, why not consider sharing this with our community.  

By writing an electrical note, you will be educating our users and at the same time promoting your expertise within the engineering community.

To get started and understand our policy, you can read our How to Write an Electrical Note