Unit 9: Magnetism



     If you feel attracted this unit it's not surprizing...magetism is a very interesting topic. We'll start off by understanding the relationship between electric charge and magnetism and move on to explain the operation of an electric motor. The picture shown above exhibits repulsion by diamagnetism, a phenomenon wherein materials respond to an external magnetic field by creating an opposing field. In this case a set of neodymium magnets repels a thin piece of graphite. Magnetism in materials has been noted in both eastern and western cultures for thousands of years, but its understanding has been a relatively recent phenomenon (beginning in the the 1800s), due to the cause of magnetism being related to the motion of electrons.

Suggested timeframe: 3 weeks

Big Ideas:
1. The source of a magnetic field is a moving charge.
2. Current carrying conductors can exert force on each other.
3. Magnetic flux is associated with magnetic field being "captured" by conducting loop.
4. Changes in magnetic flux cause induced currents.