Electrician exam study guide: the NEC and your state bulletin

Which edition your exam uses

Washington’s PSI bulletin, dated October 30, 2025, names the 2020 NEC for code questions. Check with L&I which edition applies when you test.

What the Texas journeyman exam covers

The Texas bulletin is a good map of what most journeyman exams test. Here are the subject areas on its NEC knowledge part, with the number of questions from each.

Theory and calculations

Every exam expects you to handle basic electrical math. Texas puts it in a separate calculations part, and Washington folds theory questions into its NEC section. California lists textbooks on electricity and Ugly’s Electrical References among the books its questions were written from.

The formulas to know cold are Ohm’s law (E = I × R), the power formulas (P = E × I and P = I² × R), series and parallel resistance, voltage drop, three-phase power with 1.732, and transformer ratios.

How to use the code book well

• Learn the layout first. Article 90 is the introduction, Article 100 holds the definitions, and Chapter 9 holds the tables.
• Know where the big articles are, such as 210 branch circuits, 240 overcurrent protection, 250 grounding and bonding, and 430 motors.
• Use the index. It’s the fastest way into the book for a topic you don’t know by heart.
• In Texas, highlight and tab your book before the exam, within the bulletin’s rules. You can’t mark it during the exam.
• Answer by the main rule. Texas tells you to ignore exceptions and optional calculation methods unless a question asks for them.

About question-and-answer PDFs

State exam questions are kept secret. California’s bulletin says its questions are copyrighted and copying them can bring civil and criminal penalties. Practice books and PDFs are written by prep companies, so use them for practice, but treat the state bulletin as the real guide to what’s on the test.