Static electricity

• Static electricity - a charge caused by an imbalance of positive and negative charges in or on an objects surface, which is caused by friction
• How static electricity is caused:

  1. Two insulators materials are rubbed together
  2. Electrons are transferred from one object to another
  3. One object becomes positively charged, while the other becomes negatively charged
• Electric spark - the passage of electrons across a gap between a charged object and the earth (or an earthed conductor)
• How an electric spark occurs:

  1. Electric charge builds up on object
  2. Potential difference between object and earth increases
  3. When potential difference is large enough, the charge jumps through the air from a negative object to a highly positive object
  4. This causes a spark
• What precaution must be taken to prevent the build up of static charge?

  Surfaces that are rubbed against each other should be earthed, this allows charge to flow off material.