MAGNETIC MATERIALS

1. MAGNETIC MATERIALS

3. EARTH’S MAGNETISM The Earth itself has a huge magnetic field - as if it had a huge bar magnet embedded at its centre. The Earth’s magnetic field lines emerge from near the geographical north pole and re-enter it at the south pole. The nature of the field around the Earth varies in both strength and direction. The Earth’s magnetic field is strongest at the magnetic poles and weakest near the Equator.

4. Why does the Earth have a magnetic field? The Earth has, at its centre, a dense liquid core, of about half the radius of the Earth, with a solid inner core. This core is though to be mostly made of molten iron and nickel perhaps mixed with some lighter elements. Circulating ions of iron and nickel in highly conducting liquid region of earth’s core might be forming current loops and producing earth’s magnetism.

5. The Earth’s magnetic field

10. When an unmagnetized substance is placed in a magnetic field, the substance can become magnetized. This happens when the spinning electrons line up in the same direction.