Magnets and Magnetic fields

• What are the 2 types of magnets?

  • permanent magnets
  • induced magnets
• What are permanent magnets?

  Magnets that produce their own magnetic fields, all the time
• What are induced magnets?

  Magnetic materials that become magnets when they are placed in a magnetic field, and they only have a magnetic field temporarily
• What is a magnetic field?

  A region around a magnet where a force acts on another magnet or magnetic material
• When an induced magnet is placed in a magnetic field, what does the strength of it and the permanent magnet's connection depend on?

  The distance the induced magnet is from the permanent magnet (the further away the induced magnet is, the smaller the force of attraction)
• When drawing magnetic field lines, what way should the arrows be pointing?

  Out of north and into south
• On a magnetic field drawing, where is the magnetic field the strongest? why?

  The strongest part of a magnetic field is at the poles of the magnet because that is where the field lines are more dense (close together)(the more dense field lines are, the stronger the magnetic field)
• What happens when two poles of magnet are put near each other?

  They will exert a force on each other
• If two poles that are the same are put near each other, what will happen?

  The force will be repulsive, so the poles will repel
• If two poles that are opposite are put near each other, what will happen?

  The forces will be attractive, they will attract
• How can a compass be used to draw a magnetic field?

  • Inside a compass there is a tiny bar magnet, the north pole of this magnet is attracted to the south pole of any other magnet that is near - so the compass points in the direction that the magnetic field is in
  • You can draw out the magnetic field using a compass by moving a compass around a magnet and tracing its position onto some paper to build a picture of what the magnetic field looks like
• When a compass is not near a magnet, what direction does it always point, why?

  When a compass is not near a magnet it always points north. This is because the Earth generates its own magnetic field, which shows that the core of the Earth must be magnetic