Magnetic Fields

• What is a Magnetic Field?

  • The region around a magnet where a force acts on another magnet or on a magnetic material
• What are 4 Magnetic Materials?

  • iron, steel, cobalt and nickel
• How are the Forces between a Magnet and Magnetic Material held?

  • By Forces of Attraction
• Strength of the Magnetic Field

  • Depends on the distance from the magnet
  • The field is strongest at the poles of the magnet
• Direction of Magnetic Field

  • The direction of the magnetic field at any point is given by the direction of the force that would act on another north pole placed at that point
  • Direction of a magnetic field line is from the north pole of a magnet to the south pole of the magnet

  
• How to plot the magnetic field pattern of a magnet using a compass

  1. Place Plotting Compass at Pole of Magnet
  2. Draw a dot where the Arrow on the Compass is pointing towards
  3. Repeat until Compass reaches the other Pole
  4. Connect the Dots to produce the Magnetic Field pattern of the Bar Magnet
  5. Add Arrow to show direction of Field Line
• How do we know that the Earth's core is Magnetic?

  • A magnetic compass contains a small bar magnet.
  • The Earth has a magnetic field.
  • The compass needle points in the direction of the Earth’s magnetic field and produces a Magnetic Field Pattern