Book excerpt: Electricity powers the applications that make our daily lives more productive and efficient. The demand for electricity has led to vast job opportunities in the electrical field. Electricians install electrical systems in structures. They install wiring and other electrical components, such as circuit breaker panels, switches, and light fixtures. NCCER and Pearson are pleased to present a fresh format for this edition of Electrical. This seventh edition has been updated to meet the 2011 National Electrical Code and includes revisions to the module examinations. - To the trainee.