1. Chapter 36 Magnetism

2. The Big Idea A changing electric field makes a magnetic field. This means that a moving charge makes a magnetic field. James Maxwell

3. Some Facts We use the letter B to represent the magnetic field. It is a vector field. It is measured in Teslas or Webers or Gauss. Tesla Weber Gauss

4. Magnetic Poles Two Poles: North and South. Magnetic poles always exist in pairs. Keep breaking a magnet in half and you will never isolate a single pole.

5. Magnetic Fields Compare the magnetic field produced by a bar magnet and the electric field produced by two charges. Magnetic Field from a bar magnet Electric Field from two opposite charges

6. Magnetic Field Produced by a Current in a wire. Use the “Right Hand Rule” With your right hand point your thumb towards the direction that the current flows. As you curl your fingers, the magnetic field points the way your fingers do.

7. One more important Fact A changing magnetic field will create an electric field. When this electric field is created by a conductor, a current will flow through the conductor. The current in the conductor is said to be induced.

8. Induction Using a changing magnetic field to induce a current is how all electricity is made. Nikola Tesla is THE man who created the AC generator. His device uses magnets to induce an alternating current in a wire.

9. Other source of magnetic Fields Some material, by it’s nature, is magnetic.