Forces, mr nance

• • Atoms have a nucleus at the centre that contains protons and neutrons.
  • Electrons orbit the atom
  • These atoms make up matter
• Conductors allow electricity through them easily as they contain free electrons which move around when there's a potential difference across it.
• A conductor allows electricity to flow through it easily. A good example would be copper wire.
• • Magnetic force is strongest at a magnet's ends, or poles.
  • All magnets have a north and south pole.
• Like poles repel - push away from each other. Opposite poles attract - pull towards each other.
• When a compass needle is placed inside a bar magnet, the needle lines up with the direction of the magnetic field. This shows us that the magnetic field can be represented by imaginary lines called field lines.
• Magnetic field


  Lines that extend from one pole of the magnet and curve around to the other pole
• Like poles (north-north or south-south) of two magnets

  Repel each other
• Opposite poles (north-south) of two magnets


  Attract each other
• Electric field


  Produced by objects with a positive or negative electric charge
• Opposite charges (+/-)


  Attract each other
• You can detect a magnetic field by observing how it affects a charged object
• Electric field strength


  Not uniform, stronger for objects with greater charge and as you get closer to the object
• Magnetic field strength


  Gets stronger as you get closer to the magnet, and a bigger magnet has a stronger field than a smaller magnet of the same material
• Electromagnet


  A magnet that can be turned on and off, made by coiling wire with or without a metal core
• How electromagnets work


  1. Electric current flows through the wire coil, creating a magnetic field

  2. Adding more coils or increasing current makes the magnetic field stronger