Static electricity

• What is static electricity?

  Static electricity is the build-up of charge on insulating materials.
• Why do most materials have an overall neutral charge?

  Most materials are neutral because the positive protons and negative electrons cancel each other out.
• What happens when two insulating materials are rubbed together?

  Friction causes electrons to be rubbed off one material and onto the other, creating static charges.
• Why do electrons flow back in conducting materials like metal?

  Electrons flow back in conducting materials because they are able to move freely.
• What is the result of rubbing a polythene rod with a cloth?

  The polythene rod gains a negative charge, while the cloth becomes positively charged.
• How does the transfer of electrons affect the charge of materials?

  Only negative electrons are transferred, resulting in positive charges for materials that lose electrons.
• What happens when an object keeps gaining negative electrons?

  A potential difference develops between the charged material and the earth.
• What is the significance of the earth being at zero volts?

  Earth objects are always at zero volts, which allows for the potential difference to create a spark.
• What occurs when the potential difference is large enough between a charged object and the earth?

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

  Yes, charges can build up on conductors, but it is less common.
• How can cars build up charge?

  Cars can build up charge due to their metal frame being in contact with the wind.
• What happens when you touch a charged car?

  You may experience a small electric shock as the car discharges to the earth through your body.
• What are the key points about static electricity and charge transfer?

  • Static electricity is the build-up of charge on insulating materials.
  • Charges cancel each other out in neutral materials.
  • Rubbing materials can transfer electrons, creating static charges.
  • Only negative electrons are transferred, leading to positive charges on losing materials.
• What is the process of charge build-up and discharge in relation to static electricity?

  • Gaining electrons increases charge and creates a potential difference.
  • Earth is at zero volts, allowing for electron jumps.
  • A spark occurs when the potential difference is sufficient.
  • Charges can build up on conductors, though less commonly.