1. Electricity and Magnetism

2. Moving Charges and Magnetic Fields
Moving charges produce magnetic fields
Magnetic field lines form circles around a wire
The direction of the field reverses as the current reverses

3. Electromagnets
A temporary magnet made by wrapping a wire coil carrying a current around an iron core
Solenoid  wire wrapped into a cylindrical coil

4. Speakers
Contains an electromagnet connected to a flexible speaker cone made of paper, plastic, or metal
Electrical Energy  Mechanical Energy  Vibrates Speaker Cone  Produces Sound

5. How A Speaker Is Made
Speaker Video