Conductors:

Mostly metals
The metal atoms contain free moving electrons that are able to carry the current
These electrons collide with the metal ions to create a resistance to the electronic flow
e.g. steel, iron, silver, copper, aluminium, graphite & silicon
Allows an electric current to flow through them
The length of a conductor is directly proportional to the resistance e.g. the double the length of the copper wire, the double the resistance
However, the resistance is inversely proportional to the cross-section area e.g. The more electrons in the wire, the less resistance.

Insulators:

Mostly plastics
Can be charged with static electricity by using friction
Extra electrons are added to the insulating material
The electrons stay at the surface of the material and attracts itself to something that ispositively charged
When you rub a polyethene rod with a cloth, electrons transfer from the cloth to the rod. Therefore, it gains a negative charge.
You can also take away electrons from the material so that it carries a positive charge

	Created by ShreyaDas over 10 years ago

IGCSE Physics (P3 Electricity) Note on Electricity, created by ShreyaDas on 04/04/2014.

Electricity