1. Principles of Physics Magnetism Basics

2. Magnets Any object with the ability to exert forces on other magnets or magnetic materials (iron, cobalt, nickel) ExBar magnets Horseshoe magnets Electromagnets Earth

3. Magnets Can cause magnetic materials to become magnetized If material stays magnetized it is a permanent magnet Always have two poles End that points northward is north pole End that points southward is south pole

4. Single poles cannot be isolated When a magnet is cut both pieces will still have both poles N S N N S S = + Magnets

5. Magnetic Fields → B-Fields If compasses are placed around a magnet If iron filings are placed around a magnet

6. Magnetic Fields → B-Fields Show how another magnet will behave around the magnet producing the fields Direction at a point around a magnet is the direction a compass points if placed at that point

7. Magnetic Fields → B-Fields Field Lines… point away from N toward south outside magnet point away from S toward north inside magnet always form closed loops never cross show strongest magnetic strength where closest together

8. If the field lines point in the same direction If field lines point in opposite directions They repelThey attract

9. Permeability Ability of a material to become magnetized when placed in a magnetic field -high permeability = easy to magnetize -low permeability = difficult to magnetize Where in the magnetic field of a bar magnet should you place a nail if you wish to magnetize it? Why? Near the end where the field is strongest

10. Earth is a magnet whose magnetic poles migrate Current magnetic north pole is located in Antarctica and magnetic south pole is located in the Arctic Circle Why is the magnetic north pole located at the geographic south pole? Because North magnetic poles point toward South magnetic poles North South