What NEC edition does the app test?
Every question in the bank is written to the 2023 National Electrical Code — all 2,720 of them. The app doesn't mix editions, because a question that's right in one cycle can be wrong in the next. It also tracks which NEC edition your state has actually adopted, so you can see when your jurisdiction sits behind or ahead of the 2023 code.
How many practice questions are in the app?
2,720 questions. 1,868 carry a direct NEC article citation, covering 925 distinct articles, and 1,425 have been through review and are mapped to the ten exam outline areas that state journeyman exams are built from.
Does the app simulate a real journeyman electrician exam?
Yes. Mock Exam mode runs a full-length, timed, open-book paper weighted to the exam outline rather than to the bank — so Wiring Methods carries the weight your state gives it, not the weight it happens to have in the question pool. You're scored against the real pass mark at the end.
What is the Readiness Score?
A single number estimating how close you are to passing, built from your accuracy per outline area, your recent trend, and how much of the blueprint you've actually covered. It moves as you practice and names the areas dragging it down — so you study the weak article instead of the comfortable one.
Is the app free?
Free to download on iOS and Android, including a free question set and the Daily Code Challenge. Pro unlocks the full 2,700-question bank, full-length mock exams and every practice mode, as a monthly or annual subscription. Current pricing is shown on the store listing.
Which states does it cover?
NEC adoption, testing vendor and licence class are tracked for all 50 states plus DC — 34 of which issue a journeyman electrician licence. Texas ships with a full exam blueprint weighted to the official TDLR/PSI Candidate Information Bulletin, and further state blueprints are being added.
Does every answer show the code reference?
Every explanation that maps to a specific rule names the article inline — 1,868 questions carry one. That's the point: you learn where the answer lives in the book, not just which letter was right. The real exam is open book, and finding the rule fast is the skill being tested.
What calculation types can I drill?
Nine — dwelling load calculations, ohm's law, motor calculations, conductor ampacity, conduit fill, box fill, voltage drop, transformer calculations, and grounding and bonding sizing. Calc Drills isolate one type at a time so you build speed on the arithmetic that eats exam minutes.
Can I compete against other electricians?
Yes — 1v1 and group battles on timed NEC questions, plus the Weekly Code Cup leaderboard that resets every week. Both draw from the full question bank regardless of subscription, so free users see pro-tier questions during contests.
Is this app affiliated with the NFPA?
No. VoltageLab is an independent study tool. NEC® and NFPA 70® are registered trademarks of the National Fire Protection Association, which does not endorse this app. The app is a practice aid — it is not a substitute for the code book, and you should verify anything exam-critical against the edition your jurisdiction has adopted.
