CSLB Electrical (C-10): Online Practice Exam

What this exam covers

Practice questions for the California CSLB Electrical (C-10) license exam, delivered online and graded instantly. Per the state's classification, a C-10 contractor installs, erects, constructs, repairs, services, alters, adds to, or designs electrical wiring, services, equipment, and apparatus for light, heat, and power. Works on any device, including iPad. See the official CSLB C10 classification.

Updated July 2026 · 2022 CA Codes · 592 Questions · Topic Practice

• Content Last Updated: July 24, 2026
• Code Basis: 2022 California Codes
• Question Count: 592 practice questions
• Organized By: CSLB study-guide topic categories
• Includes: This practice exam has been updated using Peerless’s vetted usable question set. Questions are organized by CSLB study-guide topic categories and include answer explanations to support full-exam review and focused topic practice. Each topic has a mini-exam to help you develop mastery.

Sample questions — Try our free practice test

1. A shunt is used in parallel with a d. c. ammeter measuring large currents to:
   A. dampen the meter pointer · ✓ B. reduce the meter current · C. protect the meter against shorts · D. increase the sensitivity of the meter
2. The minimum clearance from ground to service conductors over a public street is:
   A. 12' · B. 15' · ✓ C. 18' · D. 21'
3. When you check a 3 phase motor winding for polarity with a compass, the pointer should indicate :
   ✓ A. the same number of alternate north and south poles · B. the same number of alternate poles as there are phases · C. a north pointer deflection in the direction of rotation · D. a south pointer deflection in the direction of rotation
4. Electric-discharge lighting mounted on poles or other structures outdoors and supplied by circuits exceeding 277V nominal to ground, but not exceeding 600V phase-to-phase, must have a minimum height of _______ft above the grade, roadway, etc.
   A. 10 · B. 12 · C. 18 · ✓ D. 22
5. To measure the voltage across a load, you would use a(n):
   A. voltmeter in series with the load · ✓ B. voltmeter across the load · C. ammeter across the load · D. ammeter in series with the load