This is the first of a two-volume work covering the electrical principles syllabuses of all the major examining bodies including City & Guilds of London Institute's electrical craft courses. It is also suitable for a wide range of other courses, including the first three years of the BTEC electrical series. Great care has been taken to ensure that the text fully covers the content of the syllabuses concerned, both as published and as interpreted by the examiners in the past. The book is well illustrated with almost 200 line diagrams and photographs. Theories are explained with the help of almost 100 worked examples, an important aid to understanding the practical applications, and there are more than 300 graded exercises for which numerical answers are provided as well as nearly 250 multiple choice questions with solutions. These features make the book ideal as a class text as well as being particularly suitable for private study. A complete list of symbols, abbreviations and units is included, along with eight tables of relevant data and introduction to SI units, this system being used throughout. Each chapter concludes with a summary of the formulas introduced in it. This book will also be useful to practicing technicians wishing to extend their grasp of electrical principles to meet the rapidly expanding requirements of the industry.