Static Electricity

• What is static electricity?

  Build-up of charge on insulating materials
• Why do most materials have an overall neutral charge?

  Positive protons and negative electrons cancel out
• What happens when insulating materials are rubbed together?

  Electrons are transferred, causing charge build-up
• What occurs in conducting materials when rubbed together?

  Electrons flow back, preventing charge build-up
• What is an example of an insulating material?

  Polythene rod
• What happens to the cloth when rubbed against a polythene rod?

  Cloth loses electrons, becoming positively charged
• What happens to the polythene rod when rubbed against a cloth?

  Polythene rod gains electrons, becoming negatively charged
• How does the transfer of electrons depend on materials?

  It varies based on the specific materials involved
• What happens when an acetate rod is rubbed with a cloth?

  Acetate rod loses electrons, becoming positively charged
• What causes positive static charges on objects?

  Loss of negative electrons, not gain of protons
• What develops as more electrons are transferred to an object?

  A potential difference between the object and earth
• What is the potential difference of earth objects?

  Always at zero volts
• What happens if the potential difference is large enough?

  Electrons can jump across the gap, creating a spark
• Can charges build up on conductors?

  Yes, but it's less common
• How can cars build up charge?

  Metal frame contacts wind, transferring electrons
• What happens when you touch a charged car?

  You may experience a small electric shock
• What is the process of static electricity generation through friction?

  • Rubbing two insulating materials together
  • Electrons are transferred from one material to another
  • One material becomes positively charged, the other negatively charged
• What are the key points about charge transfer in static electricity?

  • Only negative electrons are transferred
  • Positive charges result from loss of electrons
  • The specific materials determine the direction of electron transfer