CSLB General Building (B) Trade Practice Test
Frequently asked questions
How many CSLB C-10 Electrical trade questions are here?+
480+ original practice questions across the content areas of the C-10 electrical exam — Planning & Estimating, Services & Distribution, Branch Circuits & Wiring, Equipment & Systems, Testing & Troubleshooting, and Safety — with 2023 NEC / 2025 California Electrical Code references.
Is the C-10 trade exam separate from the Law & Business exam?+
Yes. To get a C-10 Electrical contractor license you must pass BOTH the Law & Business exam AND this C-10 trade exam. They are two separate exams, each about 3.5 hours at a PSI testing center.
Which code is the C-10 exam based on?+
The California Electrical Code (Title 24, Part 3), which adopts the National Electrical Code (NEC / NFPA 70) — currently the 2023 NEC. Expect code-lookup, load calculations, conductor/box/conduit sizing, grounding & bonding, and motor questions. A calculator is provided.
Are these the real CSLB exam questions?+
No. Every question is 100% original, written from public sources (the 2023 NEC / 2025 California Electrical Code and Cal/OSHA Title 8). We never copy real exam questions or paid prep material.
Can I study the C-10 material in Chinese or Spanish?+
Yes — PrepPass practice and study guides are in English, 中文 and Español. The official CSLB exam is offered in English (Spanish and translator accommodations may be available through CSLB); you can switch the question language to English any time to rehearse the wording you'll see at the test center.