Wednesday, November 21, 2012

Earth's Magnetic Field

The reason why a compass works is more interesting. It turns out that you can think of the Earth as having a gigantic bar magnet buried inside. In order for the north end of the compass to point toward the North Pole, you have to assume that the buried bar magnet has its south end at the North Pole, as shown in the diagram at above. If you think of the world this way, then you can see that the normal "opposites attract" rule of magnets would cause the north end of the compass needle to point toward the south end of the buried bar magnet. So the compass points toward the North Pole.

Sunday, November 11, 2012

What are the characteristics of magnets?

  • They can attract some materials.
  • They can also repel other magnets.
  • They are usually made of iron.
  • They have two ends called magnetic poles.

Tuesday, October 30, 2012

Magnet


       Kids are usually introduced to magnets early on in life, starting with a cluster of letters on the refrigerator. As they get older, they'll learn all about magnetic force and the fact that not all objects are magnetic.