In week 28 of the Ron Paul Curriculum physics course, we covered Electromagnetic applications.
AC generator and DC generator diagram
Transformers: a device for increasing or decreasing voltage. Think of hydro wires, coming from the road to a house.
Mutual inductance: Units of inductance: called a henry (H)
Self inductance: An AC circuit always contains some inductance, though it is often quite small. If in some circuits we desire to have inductance, you can build indicators into the circuit.
Impedance intro: the resistance to applying ac voltage. If the inductance is high, there will be a relatively low current. This resistance to flow of electricity is a type of impedance.