Heavily updated and expanded, this second edition of Adrian Waygood's textbook provides an indispensable introduction to the science behind electrical engineering. While fully matched to the electrical science requirements of the 2330 levels 2 and 3 Certificates in Electrotechnical Technology from City & Guilds (Electrical Installation), the main purpose of this book is to develop an easy understanding of the how and why within each topic. It is aimed at those starting careers in electricity and electronics, as well as any hobbyists, with an array of new material to reflect changes in the industry. Waygood details the historical context of each main principle and offers a wealth of examples, images and diagrams, all whilst maintaining his signature conversational and accessible style. The book also directs readers to accompanying resources online. New chapters for this edition include: - Electrical drawings - Practical resistors - Measuring instruments - Basic motor action - Practical