Try five free Montana electrical practice questions with answers and 2020 NEC references. These 2020 NEC questions practice topics on Montana’s journeyman, master and residential exams. Montana’s field installation code and its exam reference edition can differ; study the edition in PSI’s exam bulletin. Work with your code book open, record your answers, then open the explanations below.
Start with the Montana exam guide for the official bulletin, approved books, exam format and registration steps.
Approved by the Board? JCR's Montana self-study package is built on the 2020 NEC that PSI grades all three exams on. For $495 you get 100 video lessons (21 hours), JCR's 152-page workbook with a six-week plan, a 500+ question mock exam in print and online, and permanent tabs for your code book.
Which Montana exam are you preparing for?
| Quick facts | Montana electrician exams |
|---|---|
| Test company | PSI, at 7 Montana test sites (Billings, Butte, Great Falls, Kalispell and Missoula) or any PSI center in another state |
| Rules | PSI Montana Electrician Examinations bulletin, dated January 23, 2026 |
| Master Electrician | 80 questions, 240 minutes, 75% to pass, $85 |
| Journeyman Electrician | 60 questions, 180 minutes, 70% to pass, $75 |
| Residential Electrician | 50 questions, 150 minutes, 70% to pass, $75 |
| Code edition | 2020 NEC on all three exams |
| Books | Open book. Tabs, indexes, highlights, underlining and your own notes are allowed if added before exam day. |
| Before you book | Board approval and an admission letter. You apply through the state licensing portal with a $190 application fee. |
Review Montana amendments and the other references listed for your exam. This short set does not cover the complete master, journeyman or residential outline.
Montana electrical practice test: 5 questions
Use 15 minutes as a practice target. This is a short NEC lookup drill, not a full-length exam or a prediction of your score. Questions are selected from JCR’s practice bank and may also appear in other JCR state guides.
Question 1: Working space
A 480Y/277-volt switchboard has exposed live parts on both sides of the aisle in front of it. What is the minimum depth of working space?
- 3 feet
- 3½ feet
- 4 feet
- 5 feet
Question 2: Grounding
A branch circuit is protected by a 60-amp breaker. What is the smallest copper equipment grounding conductor allowed for it?
- 12 AWG
- 10 AWG
- 8 AWG
- 6 AWG
Question 3: Motors
A 10 hp, 230-volt, single-phase motor runs in continuous duty. What is the minimum ampacity for its branch-circuit conductors?
- 50 amps
- 57.5 amps
- 62.5 amps
- 68.75 amps
Question 4: Box fill
A metal box has four 12 AWG insulated conductors, two 12 AWG equipment grounding conductors and one receptacle on a single yoke. It has no internal clamps or fittings. What minimum box volume do these require?
- 13.5 cubic inches
- 15.75 cubic inches
- 18 cubic inches
- 20.25 cubic inches
Question 5: Wiring methods
Type NM cable runs exposed along the face of a joist. It is secured within 12 inches of each box. What is the most distance allowed between supports along the rest of the run?
- 3 feet
- 4½ feet
- 6 feet
- 10 feet
Answer key with 2020 NEC sections
Finish all five before opening the answers. Give yourself one point for each correct choice, then look up every missed section.
Show the answer to question 1Hide the answer to question 1
1. C, 4 feet (NEC Table 110.26(A)(1))
The switchboard is 277 volts to ground, which falls in the 151–600 volt row. Exposed live parts on both sides is Condition 3, so the minimum depth is 4 feet. Condition 2 (grounded parts across the aisle) would be 3½ feet. See all three conditions explained.
Show the answer to question 2Hide the answer to question 2
2. B, 10 AWG (NEC Table 250.122)
Table 250.122 sizes the equipment grounding conductor by the overcurrent device ahead of it. For a 60-amp device, the minimum is 10 AWG copper or 8 AWG aluminum. See more Table 250.122 examples.
Show the answer to question 3Hide the answer to question 3
3. C, 62.5 amps (NEC Table 430.248 and 430.22)
Use the table current, not the nameplate. Table 430.248 lists 50 amps for a 10 hp, 230-volt single-phase motor. Section 430.22 requires 125% of that: 50 × 1.25 = 62.5 amps. The 57.5-amp choice is the table value for a 200-volt motor.
Show the answer to question 4Hide the answer to question 4
4. B, 15.75 cubic inches (NEC 314.16(B))
Count 4 for the insulated conductors. All the equipment grounding conductors count as 1 when there are four or fewer. The yoke counts as 2. That's 7 × 2.25 cubic inches (the 12 AWG allowance) = 15.75. Walk through more box fill examples.
Show the answer to question 5Hide the answer to question 5
5. B, 4½ feet (NEC 334.30)
NM cable must be secured at intervals of no more than 4½ feet and within 12 inches of every box, cabinet or fitting it enters. The 2020 NEC also caps the cable between the box entry and the first support at 18 inches.
How to study after this practice test
- Log the lookup. Write down the article, section or table you used and how long it took to find.
- Work the calculation again. Keep the units and intermediate steps so you can find an arithmetic error.
- Use your exam’s edition. A newer installation code is not automatically the edition used for your license test.
- Cover the full outline. Review Montana amendments and the other references listed for your exam. This short set does not cover the complete master, journeyman or residential outline.
Montana electrical practice test FAQ
Are these actual licensing exam questions?
No. These are JCR practice questions selected to help you study NEC rules. They are not supplied or endorsed by the exam vendor or licensing board.
Does getting all five right mean I am ready?
Five questions are too small a sample to judge readiness. Use a full practice exam, review the official content outline and practice every required subject.
Which NEC edition does this practice test use?
This set uses the 2020 NEC. These 2020 NEC questions practice topics on Montana’s journeyman, master and residential exams. Montana’s field installation code and its exam reference edition can differ; study the edition in PSI’s exam bulletin.
Keep practicing for your Montana exam
Use the course links above for the exam and edition you are taking. Review the complete Montana exam guide before you order.
Try JCR’s free NEC practice app. Check the edition shown in the app before using its questions for your exam.
More Montana guides
Sources and answer references
- PSI Montana State Electrical Board Electrician Examinations bulletin (January 23, 2026)
- Montana State Electrical Board: Exam information
- Montana Building Codes: Current codes
- Journeyman Electrician checklist
- Master Electrician checklist
- Residential Electrician checklist
- ARM 24.141.503: Examinations
- NFPA 70, 2020 edition: see the section citations in each answer.
- JCR washington electrical practice test: source practice-bank questions.
- JCR new mexico electrical practice test: source practice-bank questions.
- JCR maryland electrical practice test: source practice-bank questions.
Reviewed October 22, 2026. NEC answers and section references checked against the stated edition in NFPA LiNK. Exam information follows the linked official bulletins. Questions are selected from JCR’s shared practice bank, with clarifications where needed.