DC Theory, 3rd Edition from the NJATC is a core textbook on direct current for electrical apprentices and journeymen, covering voltage, current, resistance, Ohm’s law, series and parallel circuits, power, energy, and basic magnetism, along with practical examples tied to real electrical installations. Chapters include clear explanations, worked examples, and end‑of‑chapter problems that build the math and theory skills needed for on‑the‑job calculations and troubleshooting in the electrical trade. Your copy is brand new and still factory sealed, with a pristine cover and untouched pages, making it an ideal primary text or backup reference for an electrical training program or for anyone wanting a fresh, unused copy of this NJATC DC theory book.