Magnetic fields

• What two things can magnets be?

  Permanent or induced.
• What are the four types of magnetic material?

  Nickel

  Cobalt

  Iron

  Steel

  All of these materials can be made into a permanent or induced magnet.
• What is a magnetic field?

  A region around a magnet where a force acts on another magnet or on a magnetic material. For example, if we placed iron in a magnetic field, it will experience a force of attraction towards the magnet.
• What does the strength of the magnetic field depend on?

  The distance from the magnet.
• The direction of a magnetic field can be found using a what?

  A compass, which contains a small bar magnet. If we place a compass near a bar magnet, then we can plot the magnetic field.
• How do we use a compass to plot the magnetic field?

  First, place the compass near the north pole of the bar magnet, then draw a cross at the north pole of the compass. Now move the compass so the south pole of the compass is on the cross. Then draw another cross at the north pole of the compass. Keep doing this until you have plotted a complete magnetic field line. Connect the dots with a line. show the direction of the field line using an arrow. The direction always runs from North pole to south pole. Repeat this starting at different points around the North pole of the bar magnet.
• What happens if we hold a magnet away from a compass?

  Then the needle always points in the north-south direction. This tells us the Earth has its own magnetic field and its due to the Earths core.