1.  An Introduction to Magnetism

2. Permanent Magnets Have north “poles” and south “poles” Like poles repel, opposites attract Most, but not all, metals are attracted to magnets (and magnets are attracted to metal)….and these metals are attracted to either pole The needle on a compass is magnet and the end that points north is named the north pole.

3. The Magnetic Force The force is strong. It is neither gravitational (too strong for that) nor electrostatic (no excess charge need be present). A new kind of force-the magnetic force.

4. The Earth Is a Big Bar Magnet

5. Current Carrying Wires Produce Magnetic Forces Current carrying wires produce magnetic forces. What evidence do we have? Current carrying wires deflect compass needles, can pick up iron objects and interact with permanent magnets. This picture shows the simplest of “electromagnets” (magnets produced by running current through a wire).