The 2020 National Electric Code CALCULATIONS practice exam & study guide by Ray Holder is a comprehensive textbook focusing on electrical code calculations. Published by Brown Technical Publications, Inc in 2020, this study guide is designed for high school, adult education, and vocational school students. Written in American English, the textbook covers essential concepts related to the National Electrical Code, making it an invaluable resource for those seeking to enhance their understanding of electrical code calculations. With a trade paperback format, this publication offers a convenient and informative learning tool for students and professionals alike.