Static Electricity

• What is static electricity?

  Build-up of charge on insulating materials
• What causes sparks in static electricity?

  Discharge of built-up charge
• What do all materials contain that contributes to charge?

  Positive protons and negative electrons
• Why are most materials neutral overall?

  Positive and negative charges cancel each other out
• What happens when materials are rubbed together?

  Electrons are transferred between them
• What occurs in conducting materials when rubbed?

  Electrons flow back, no charge builds up
• What happens in insulating materials when rubbed?

  Electrons can't flow back, charge builds up
• What charge does a polythene rod gain when rubbed with cloth?

  Negative static charge
• What charge does cloth gain when rubbed with a polythene rod?

  Positive static charge
• How does the transfer of electrons depend on materials?

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

  Electrons transfer from acetate to cloth
• What is the key point about static charge transfer?

  Only negative electrons are transferred
• What happens when an object gains more negative electrons?

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

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

  Electrons can jump across the gap
• What is a spark in terms of static electricity?

  Jumping of electrons across a gap
• 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 result of a car discharging to the earth?

  A small spark through your body
• What are the key concepts of static electricity?

  • Build-up of charge on insulators
  • Charge cancellation in neutral materials
  • Electron transfer through friction
  • Potential difference and sparks
  • Charge accumulation on conductors
• What are the differences between conductors and insulators in static electricity?

  Conductors:

  • Electrons can flow back
  • Charge does not build up easily

  
  

  Insulators:

  • Electrons cannot flow back
  • Charge builds up due to friction
• What are the steps involved in the charging process through friction?

  1. Rubbing two materials together
  2. Electrons transfer from one to another
  3. One material becomes positively charged
  4. The other material becomes negatively charged