In this module the student will study and learn what voltage is, how it is generated, what AC (alternating current) and DC (direct current) are and why both kinds are needed, and how to measure voltages. The module is divided into six lessons: EMF (electromotive force) from chemical action, magnetism, electromagnetic induction, AC voltage, the uses of AC and DC, and measuring voltage. Each lesson consists of an overview, a list of study resources, lesson narratives, programed instructional materials, and lesson summaries. (Author/BP)