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Master electrician practice test

20 harder questions written from the 2026 NEC. Master exams go deeper into equipment, special occupancies, and the rules behind design decisions. Every answer comes with the section that settles it.

2026 NEC · 20 questions · Free, no sign-up · Updated October 2026

Keep your code book open, the way you will on exam day. Try to find each answer in the book before you check it.

0 of 20 answered0 correct
  1. 1.Equipment intended to interrupt fault current must have an interrupting rating at least equal to what?
  2. 2.The current code requires a product that is not yet available. What may the authority having jurisdiction permit?
  3. 3.Which of these must an arc flash marking on service equipment in a commercial building contain?
  4. 4.A 30-ampere circuit feeds equipment (not a motor) whose terminals are not listed and identified for higher temperatures. A 90°C conductor is used. Its ampacity must be based on what temperature rating? (°C)
    °C
  5. 5.A switchboard containing overcurrent devices is wider than 6 ft. At what ampere rating or more does it need a working-space entrance at each end? (amperes)
    A
  6. 6.For load calculations, how is a power control system (PCS) control setting treated?
  7. 7.An existing bedroom branch circuit is extended with no new outlets or devices other than splices. Up to what length of extension can AFCI protection be skipped? (feet)
    ft
  8. 8.A feeder tap not over 25 ft long ends in a single circuit breaker that limits the load to the tap ampacity. The tap needs an ampacity of at least what fraction of the feeder OCPD rating?
  9. 9.A service has 2/0 AWG copper ungrounded service conductors. What is the minimum size copper grounding electrode conductor? (AWG)
    AWG
  10. 10.A 75°C-rated conductor is installed in a 40°C ambient. What ambient temperature correction factor applies? (percent)
    %
  11. 11.Interlocked-armor Type MC cable has unshielded conductors. The inside of a bend needs a radius of at least how many multiples of the metallic sheath's external diameter? (times)
    times
  12. 12.A 1750 RPM, single-speed, general-purpose ac motor drives a fan across the line. What current value do you use to size its branch-circuit conductors?
  13. 13.An autotransformer of 1000 volts or less needs an overcurrent device in series with every ungrounded input conductor. That device's rating can reach what percent of rated full-load input current at most? (percent)
    %
  14. 14.Thermal insulation may not be installed above a recessed luminaire that is not Type IC, or within how far of its enclosure or wiring compartment? (inches)
    in
  15. 15.A shop produces combustible metal fibers or flyings that may be present in hazardous quantities in normal or abnormal operation. How is the location classified?
  16. 16.Unless listed for lesser depths, what is the minimum depth below normal water level for the top of the lens of a wall-mounted underwater pool luminaire? (inches)
    in
  17. 17.An ESS battery sits apart from the ESS electronics and gets field service. Its battery circuit is 480 volts dc, nominal. To service it, its series strings must split into segments of what voltage or less? (volts dc)
    V
  18. 18.No more than 4 ft of a communications cable passes over a roof overhang and ends at a through-the-roof raceway. What is the minimum clearance allowed above that overhanging portion? (inches)
    in.
  19. 19.Soft-drawn copper is allowed for antenna lead-in conductors only if the maximum span between supports is less than what length? (feet)
    ft
  20. 20.When a transformer holds down the output current of a power source classed 2 or 3, the Imax limits take effect after how many minutes? (minutes)
    min

What this test covers

  • Fault current, interrupting ratings, and arc-flash marking
  • Working space for large equipment and terminal temperature limits
  • Feeder taps, grounding electrode conductors, and ampacity correction
  • Motors, transformers, and luminaires
  • Hazardous locations, pools, and energy storage
  • Communications and power-limited circuits

Taking the exam in Texas?

Texas exams switched to the 2026 NEC on September 1, 2026. See the format, time limits, and what you can bring.

Texas exam guide

Questions about the exam

Is this practice test on the 2026 NEC?

Yes. Every question is written from the 2026 edition and checked against its text. Some states still test on the 2023 code, so check which edition your exam uses.

How is the master exam different from the journeyman exam?

It's longer and goes deeper. In Texas, for example, the master exam has 108 questions in 320 minutes, against 85 questions in 240 minutes for journeyman, with more weight on services and motor calculations.

How many questions are on the master electrician test?

It depends on the state. Texas has two parts: 75 NEC knowledge questions in 150 minutes and 33 calculation questions in 170 minutes, and each part includes unscored questions. Minnesota's Class A master exam has 80 questions in 5 hours 30 minutes.

What does the master electrician exam cost, and what do I need to sit for it?

It depends on the state. In Minnesota the application fee is $50 and isn't refundable. In Texas the fee to retake after failing a part is $78. Experience requirements for a master license differ by state, so check your state's licensing board before you apply.

What score do I need to pass?

It depends on the state. Texas requires 70% on each of its two parts, NEC knowledge and calculations. Your state's candidate bulletin lists the passing score.

Where can I practice more questions?

The Ask Shorty iPhone app has the full bank of more than 300 questions, chapter tests, and timed practice at finding answers in your book.

How these questions are made

Questions are drafted with AI help, then admitted only if the answer is backed by the 2026 NEC text or recomputed with the same calculators the app uses. Before publishing, each question on this page was read against the section it cites. We show section numbers, not code text, so you learn where to look in your own book.

More on how questions are checked. Spot a problem? Tell us and we’ll check it against the code.

Teaching a class?

Have your students practice on the job-site simulations, then build a lesson and quiz on any NEC topic, with a section number behind every claim.

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