Electrical Conductors & Insulators (DP IB Physics): Revision Note

Electrical Conductors & Insulators

Conductors

• A conductor is a material that allows charge (usually electrons) to flow through it easily

• Examples of conductors are:

  • silver

  • copper

  • aluminium

  • steel

• Conductors tend to be metals

Different materials have different properties of conductivity

• On the atomic scale, conductors are made up of positively charged metal ions within a sea of delocalised electrons

• Metals are excellent conductors of electricity because:

  • current is the rate of flow of electrons

  • they contain a large number of delocalised electrons, which are able to flow more easily

The lattice structure of a conductor with positive metal ions and delocalised electrons

Insulators

• An insulator is a material that with very few free charges, hence they do not allow the flow of charge through them very easily

• Examples of insulators are:

  • rubber

  • plastic

  • glass

  • wood

• Some non-metals, such as wood, allow some charge to pass through them

• Despite not being very good at producing an electrical current, insulators are able to conduct static electricity

  • This occurs when an insulator builds up charge on its surface

  • When a charged insulator comes into contact with a conductor, the charge can be transferred