The Earth's Magnetic Field (OCR GCSE Physics A (Gateway)): Revision Note

The Earth's Magnetic Field

• On Earth, in the absence of any magnet or magnetic materials, a magnetic compass will always point north

  • This is evidence that the core of the Earth is magnetic and creates its own magnetic field

• The Earth's magnetic field is similar to that of a bar magnet

Comparison between the Earth’s Magnetic Field and a Bar Magnet

• On Earth, the north arrow on a magnetic compass will point towards the geographic North Pole (in the Arctic Ocean)

  • This is because the geographic North Pole is a magnetic south pole (the magnetic field lines point into the pole)

  • The north pole of the magnetic compass is attracted to the Earth's magnetic south pole

• The geographic South Pole (in Antarctica) is a magnetic north pole (the magnetic field lines point out of the pole)

• The north pole of the magnetic compass is repelled from the Earth's magnetic north pole

Geographic and Magnetic Poles of the Earth