Learn the direct current (DC) principles and applications, as well as the underlying theories needed for a strong foundation in electrical technology, critical to the success of today's electrical technicians. With clear explanations and a conversational approach, DC Theory, 2E begins with the fundamentals of electricity and DC circuits, including how properties of materials are categorized within conductors, semiconductors, and insulators. In-depth coverage of Ohm's law and its relation to voltage, current, resistance, and power are also presented, followed by the theory and practical applications of electrical components connected in series. Coverage then builds on these fundamentals to tackle more complex topics, like DC parallel circuits, DC combination circuits, and magnetism and generators. With an emphasis on safety throughout, this book provides both information and safe practice, making it an ideal resource for building the knowledge needed to excel in the industry today.