Electrical principles

Power lines


Since its invention in the 1800s, electricity has played a major role in our lives. It's used for heating, lighting, telecommunications, powering machines and much more.

But what is electricity and how does it work?

Use these resources to help you understand basic electrical principles.  

  • Select a topic from the side menu.


  • Work through the topics in the order presented if you don’t know about electricity.
  • The resources are about low voltage direct current (DC) circuits. Understanding these basics will help when you cover alternating current (AC) circuits.