Introduction to Electricity II

Electricity:

- Occurs when electric charge flows.

- An energy source used to power machines and electrical devices.

- Scientists have found that we can make electricity if:
  * We pass a magnet close to a metal wire
  * We put the right chemicals in a jar with two different kinds of metal rods
  * We rub two things together, eg. a wool cap and a plastic ruler. (Static electricity)

- Electricity can flow like water from one place to another, either as a spark or as a current in a metal.

- All matter has an electric charge, but this is mostly cancelled out by the presence of matter with an opposite charge. We only see an effect when there is too much or too little electric charge in one place so that it is not cancelled out.

- Since the 19th century, electricity is used in every part of our lives.

- Most of our electric energy are from generators. The biggest generators are in power stations. Some are from photovoltaic cells or batteries.

- It arrives at our homes through wires from the places where it is made.

- Examples of application of electricity:
  * Electric lamps - light
  * Electric heaters - heat
  * Washing machines, electric cookers - doing work
  * In factories - running machines and computers.

- Electricians deal with electricity and electrical devices in our homes and factories.


Edited from,
~http://simple.wikipedia.org/wiki/Electricity