This book is written to aid the striker for Electrician's Mate 3 to qualify for advancement to that rate. Electrical currents and circuits-Ohm's Law 1 Magnetism 31 Electromagnetism and magnetic circuits 50 Induction 68 Alternating- and direct-current generators 89 Direct-current generators 103 Types of direct-current generators 115 Operation of direct-current generators 141 Direct-current motors 156 Maintenance of direct-current motors and generators 182 Direct-current controllers 209 Cables 231 Batteries 245 Electrical systems in small craft 257 Searchlights 271 Blueprint reading and sketching 292 Safety precautions 317 APPENDIX I: Answers to quizzes 328 APPENDIX II: Qualifications for advancement in rating 344