Magnets

1
21-1

• Magnets
• and
• Magnetic Fields

2
Magnets

• North and South pole
• Like poles repel
• Opposite poles attract

3
Permanent Magnets

• Hard Magnetism -
• Soft Magnetism -

• Hard to magnetize but retain magnetism
• Cobalt and Nickel

• Easy to magnetize, but do not retain magnetism
• Iron

4
Magnetic Fields

• Surround magnetized material
• Direction is the direction a compass points
• Away from N, towards S
• Strongest at the poles

5
Magnetic Fields
Where do field lines start? Where do they end?
6
What might the electric fields look like for
these magnets?
Draw them!
7
New vector symbols

• Into the page
• Out of the page

• X X X X X

• ? ? ? ? ?

8
Earths Magnetic Field
9
Aurora Borealis
10
So where do magnetic fields come from?
Witchcraft??
Ian Mckellen???