Trade-specific question bank
Practice built around California C-10 electrical contractor scenarios and code-adjacent decision making.
California CSLB · Classification C-10
California C-10 electrical contractor exam prep — online and focused on real jobsite scenarios.
Self-paced prep for the California C-10 contractor exam, with optional Law & Business in the same purchase flow — built around electrical scenarios, not generic course content.
Focus
C-10 focus
California-specific electrical prep
Questions
2.3k+ items
Exam-style trade scenarios
Access
3 or 6 months
24/7 on any device
Practice 2.3k+ California-specific C-10 items with instant rationales on phone, tablet, or desktop.
Add Law & Business when your application requires both exams.
3 months access
Exam prep package
Access length
Expanded hints, follow-up questions, and help in your language when you need more context.
$20/mo
Total
$199.00
Renewal pricing (monthly)
Monthly renewal: $40.00/month ($60.00/month with AI Pro)
Renewal becomes available after your active access expires.
Free practice test
Try a free practice test
Sample real exam-style questions with instant explanations — no login required.
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Instant explanations
8 languages
What you get
Practice built to feel like the exam, not a textbook.
Everything is oriented around the exams: how questions are phrased, what they test, and how to move quickly without losing accuracy.
Instant rationales
Review why an answer is right while the scenario is still fresh in your head.
Focused progress tracking
Stay on top of the C-10 topic areas that still need work before test day.
Online from any device
Keep moving from the office, the truck, a jobsite trailer, or home.
About the exam
What to know before you start.
A quick confirmation so you know you're on the right prep page before you start.
Who takes the California C-10 exam
The California C-10 — Electrical Contractor exam is for contractors who place, install, erect, or connect any electrical wires, fixtures, appliances, apparatus, raceways, conduits, or electrical equipment — for light, heat, power, or low-voltage communication.
This classification is built for working electricians who plan to run a licensed contracting business in California: reading plans, pulling permits, sizing services, estimating jobs, managing crews, and standing behind their own electrical work on residential, commercial, and light industrial projects.
The C-10 Trade Exam focuses on electrical theory and practice as it applies to a contractor's scope, not on the electrician-certification curriculum used for individual DIR electrician certification. Most first-time California applicants also need to pass Law & Business alongside C-10, which is why the bundle keeps both in one prep path.
Topics at a glance
Exam
C-10 — Electrical Contractor
Best fit
California applicants preparing for the C-10 contractor exam
Topic focus
Electrical theory, branch circuits, service equipment, feeders, grounding and bonding
Trade scope
Estimating, planning, plan reading, permits, code applications
Operations
Job safety, crew supervision, low-voltage systems, general contractor scope
Content status
Question bank and official sources
We keep this prep tied to CSLB documents, current code editions, and the live Test2Pro question bank.
Question bank last updated: May 2026.
When a practice item depends on a code citation, we review it against the current edition listed for this exam.
Current code references
- 2025 California Electrical Code, Title 24 Part 3(2025 edition, effective January 2026)
- 2025 California Energy Code, Title 24 Part 6(2025 edition, effective January 2026)
- 2025 California Fire Code, Title 24 Part 9(2025 edition, effective January 2026)
- California Code of Regulations, Title 8 - Cal/OSHA Safety Orders(2025 edition in the CSLB guide; current DIR text online)
- 2025 California Building Code, Title 24 Part 2(2025 edition, effective January 2026)
CSLB sources
The Test2Pro content team keeps these sources current.
We re-check them each quarter and whenever CSLB publishes major guide changes.
Why this format
Built for working contractors, not classrooms.
Most candidates are fitting study around jobsites and workdays. The format reflects that.
Self-paced
Study around jobs, estimates, and service calls instead of reshaping your week around a class schedule.
Online, no scheduling
Open the prep bank any time, from anywhere — no live class times, no commute, no prep-center appointment.
Trade-focused practice
Stay close to the California C-10 exam instead of broad electrician-school or certification content.
Coverage
What's included in C-10 prep
Below is the current breakdown of electrical topics included in the California C-10 contractor exam prep.
Supporting detail · 2.3k+
Planning and Estimating
~200+ items
- Existing system evaluation
- Plan and specification interpretation
- Electrical calculations
- Code requirements
- Material selection
- Energy production and storage project
Rough Wiring
~500+ items
- System layout
- Clearance and accessibility requirements
- Raceway and panel installation
- Wire and equipment installation
- Grounding and bonding
- Energy production and storage rough
Finish Wiring and Trim
~87+ items
- Finish device placement and installation
- Motor and equipment installation
- Wire and equipment labeling
- Trims and sealants
- Energy production and storage finish wiring
Startup, Troubleshooting, and Maintenance
~100+ items
- System energizing and testing
- Common electrical problems
- Location, repair, and replacement of faulty components
- Selection and use of electrical testing equipment
- Energy production and storage system
Safety
~300+ items
- Lockout/tagout procedures
- Personal protective equipment (PPE)
- Tools/equipment
- Hazardous materials and job site environments
Also required for most applicants
Add Law & Business when your application requires both exams.
Most first-time California contractor applicants need the business exam alongside C-10. The bundle keeps both exams in one prep path without a second purchase.
Optional exam
Law & Business
Business organization, finances, employment, insurance, contracts, public works, and safety.
If you want it separately, See Law & Business prep
2.3k+
Practice items in the C-10 bank
California-specific C-10 question coverage with instant rationales.
Trade-specific
Exam focus
Positioned around the California C-10 contractor classification, not electrician certification.
24/7
Online access, any device
Study anywhere between jobsites, estimates, and service calls.
Law & Business
Optional add-on
Bundle the required business exam in the same buying flow when you need both.
"The diagnostic showed exactly where my C-10 prep was thin. I could focus my study blocks instead of rereading everything."
MR
Marcus R.
C-10 Electrical Candidate
Common questions
Before you start.
Is this built specifically for the California C-10 trade exam?
Yes. The question bank is positioned for California C-10 applicants who want electrical-contractor-specific practice rather than generic contractor prep or electrician-certification study material.
How does Test2Pro fit into C-10 exam prep?
Use Test2Pro for online C-10 and Law & Business practice, rationales, and readiness tracking. Applications, scheduling, and testing happen outside the product.
Should I add Law & Business to my C-10 prep?
Most first-time California contractor applicants need Law & Business alongside C-10, which is why the bundle keeps both in one prep path. You can add it from the purchase card on this page.
Is this a course or a classroom program?
No. It is product-led, self-paced online exam prep. There's no class calendar, no commute, and no prep-center appointment — just exam-style practice and rationales.
How long does it take to prepare for C-10?
Most candidates cover the core C-10 material inside 3 months of part-time study. A 6-month term is the safer choice if you're juggling full-time electrical work or need extra review on estimating and code applications.
Can I study on my phone between jobs?
Yes. The practice workspace works on phone, tablet, and desktop, so you can run short sessions between service calls or estimating jobs and pick up where you left off.
Ready when you are
Start your California C-10 prep built for working electricians.
Pick the access length that fits your timeline, keep prep online and self-paced, and add Law & Business when your application requires both exams.