Static electricity

• What can happen when insulating materials are rubbed together?

  They can become (statically) electrically charged.
• Why can insulators become electrically charged when rubbed together?

  Electrons are rubbed from one material onto the other.
• What happens to the material gaining electrons when insulating materials are rubbed together?

  The material gaining electrons becomes negatively charged.
• What happens to the material losing electrons when insulating materials are rubbed together?

  The material losing electrons becomes equally positively charged.
• What happens when two electrically charged objects are brought close together?

  They exert a force on each other.
• What happens when two identically charged objects are brought close together?

  They exert a repulsive force on each other and repel.
• What happens when two oppositely charged objects are brought close together?

  They exert an attractive force on each other and attract.
• Give an example of a non-contact force.

  The repulsive or attractive force acting between two electrically charged objects.
• What is an electric field?

  A region in which a charged object will experience a non-contact electrical force.
• Where can electric fields be found?

  Surrounding any charged object.
• Describe the electric field around a charged particle.

  Strongest closest to the object and decreases in strength as you move away from the object.
• What happens to the force between two charged objects when they are moved closer together?

  The force between them becomes stronger as the separation reduces.
• In situations where sparks are unwanted, what precaution must be taken to prevent the build-up of static charge?

  Any surfaces that are rubbing against each other should be earthed to allow the charge to flow off the materials.