Electricity: Static Electricity

Electricity: Static Electricity

Understanding Static Electricity

  • Static electricity is the build-up of electric charge on the surface of objects.
  • This build-up of charge is due to the transfer of electrons and can occur when two different materials come into contact and then separate. This is known as frictional charging.
  • An object becomes positively charged when it loses electrons, and negatively charged when it gains electrons.
  • Unlike charges (positive and negative) attract each other whereas like charges (positive-positive or negative-negative) repel each other.
  • The law that describes these interactions is Coulomb’s law.
  • An object can be discharged by providing a path for the electrons to move off the object. This can be done using a grounding wire.
  • The phenomenon of static electricity can cause sparks. These occur when the electric field becomes strong enough to ionise the air particles, creating a path for a sudden flow of electrons (the spark).

Static Electricity in Everyday Life

  • Static electricity can be observed in a number of everyday situations, such as clothes sticking together when fresh out of the dryer, or the shock we get when touching a metal doorknob after walking across a carpeted floor.
  • Lightning is a natural and large-scale example of static discharge. It’s caused by the build-up of electric charge in storm clouds.
  • Electrostatic precipitators are used in industry to reduce air pollution. They give dust and smoke particles a charge so they’re attracted to the plates in a chimney stack, preventing them from being released into the atmosphere.

Understanding these core topics around static electricity will lay a solid foundation for exploring more complex concepts related to electricity and magnetism.