This 2020 NEC practice test has five questions, and 63% to 72% of people who took JCR's free 25-question practice exam got each one wrong. Answer all five with your code book open, then check the answer key, which cites the 2020 NEC section for each.
2020 NEC practice test: 5 questions
Question 1: Boxes and fittings
Three raceways with insulated 4 AWG or larger conductors enter one wall of a pull box, in the same row, for an angle pull. Their trade sizes are 3 in., 2 in. and 1½ in. What is the minimum distance from that wall to the opposite wall?
- 24 inches
- 27½ inches
- 18 inches
- 21½ inches
Question 2: Overcurrent protection
An overcurrent device protects branch-circuit conductors that feed a continuous load. The whole assembly, overcurrent device included, is listed to run at 100% of its rating. What is the largest continuous load allowed, as a percent of the device rating?
- 50 percent
- 80 percent
- 100 percent
- 125 percent
Question 3: Breakers used as switches
A circuit breaker used as a switch on a 120-volt or 277-volt fluorescent lighting circuit must:
(1) be approved for continuous duty
(2) be marked SWD or HID
- One only
- Two only
- Both one and two
- Neither one nor two
Question 4: Motors
True or false: a separate overload device protecting a 5 hp motor with a marked service factor of 1.10 must be rated at least 125% of the motor's nameplate full-load current. (JCR's quiz asks this one as true/false, so it has two choices.)
- True
- False
Question 5: Lighting
A surface-mounted fluorescent luminaire is going on the wall above a clothes closet door. It is not identified for installation inside the storage space. What is the minimum clearance to the nearest point of that storage space?
- 6 inches
- 12 inches
- 18 inches
- 24 inches
Taking the North Carolina license exam? Use JCR's free NC electrical license practice test too.
2020 NEC questions and answers
Answer all five first. Then open each answer to check yourself.
Show the answer to question 1Hide the answer to question 1
1. D, 21½ inches (NEC 314.28(A)(2))
For an angle pull, take 6 times the largest raceway in the row, then add every other raceway in that row on the same wall: (6 × 3) + 2 + 1½ = 21½ in. The 24-inch choice uses the 8× straight-pull rule. Read the full pull box breakdown.
Show the answer to question 2Hide the answer to question 2
2. C, 100 percent (NEC 210.20(A) exception)
Normally the device must be rated for the noncontinuous load plus 125% of the continuous load, which is where the 80% answer comes from. When the assembly, including its overcurrent devices, is listed for 100% operation, the exception drops that extra 25%. See the 100%-rated assembly explanation.
Show the answer to question 3Hide the answer to question 3
3. B, two only (NEC 240.83(D))
A breaker used to switch 120-volt or 277-volt fluorescent lighting must be listed and marked SWD or HID. The rule says nothing about continuous duty, so statement 1 isn't a requirement. Read the SWD and HID post.
Show the answer to question 4Hide the answer to question 4
4. B, false (NEC 430.32(A)(1))
The percentages in 430.32(A)(1) are maximums, not minimums. The 125% limit applies only with a service factor of 1.15 or more or a temperature rise of 40°C or less, so this 1.10 motor's overload can be no more than 115% of nameplate current. Work through the motor overload post.
Show the answer to question 5Hide the answer to question 5
5. A, 6 inches (NEC 410.16(C)(2))
A surface-mounted fluorescent luminaire on the wall above the door or on the ceiling needs 6 in. from the storage space. The 12-inch figure is for surface-mounted incandescent or LED luminaires with a completely enclosed light source. See every closet clearance in one table.
Studying for your electrical exam? JCR's $495 self-study package has 500+ practice questions (digital and printed), 100 video lessons, a 152-page study manual and permanent code tabs. Videos and the digital practice exams open right after you order.
Testing in North Carolina? Take JCR's NC exam prep class: two full days in person ($845) in Raleigh, Asheville, Mooresville (Charlotte area) or Winston-Salem, or live on Zoom on Tuesday evenings and Saturday mornings. 93% pass rate for JCR classroom students.
All five come from JCR's free 25-question practice exam on the 2020 NEC. Take the full exam with your code book open, like on test day.
How NEC exam questions are written
The exam handbook from the NC State Board of Examiners of Electrical Contractors (NCBEEC) lists five styles:
- Straight questions with one best answer out of four
- Fill-in-the-end statements, like "a circuit to a gas pump must have a disconnect that…"
- EXCEPT questions: pick the one choice the code doesn't require
- "I only, II only, both, neither" questions
- Calculations and questions tied to a diagram or plan
The handbook says questions aren't meant to trick you. Apply NEC exceptions unless the question rules them out.
Which NEC topics get the most exam questions?
On North Carolina's Limited, Intermediate and Unlimited exams, 100 questions span 11 topics:
| Topic | About how many questions |
|---|---|
| Bonding and grounding | Limited 10, Intermediate 11, Unlimited 11 |
| Overcurrent protection | 9 on each |
| Wiring methods and terminations | 10 on each |
| Boxes and fittings | Limited 8, Intermediate 7, Unlimited 7 |
| Services and service equipment | Limited 11, Intermediate 9, Unlimited 9 |
| Motors and control wiring | Limited 7, Intermediate 8, Unlimited 9 |
| Special occupancies and hazardous locations | Limited 6, Intermediate 9, Unlimited 9 |
| Load calculations | 11 on each |
| Appliances, equipment and lighting | 7 on each |
| General: definitions and installation | 3 on each |
| NC law, board rules, business, plans and NFPA 72 | Limited 18, Intermediate 16, Unlimited 15 |
NEC-only study misses the last row: NC licensing law, board rules, the NASCLA guide, NFPA 72 and the handbook's plans.
2020 NEC practice test questions
Where can I find a free 2020 NEC practice test?
JCR's free 25-question practice exam uses the 2020 NEC, and each most-missed question has a full write-up on JCR's blog. Keep your code book open, as on the real exam.
Where can I find an electrical exam practice test for my state?
Start with the five questions above and JCR's free 25-question exam. Then pick your state's JCR self-study package: each one is built for that state's exam and NEC edition, with 500+ practice questions.
Is there a 2020 NEC questions and answers PDF?
The NCBEEC exam handbook is a free PDF. It prints 30 practice questions for North Carolina's Limited, Intermediate and Unlimited exams, with an answer key.
Which NEC edition does the NC electrical exam use?
North Carolina tests on the 2020 NEC, plus the 2013 NFPA 72 for the Limited, Intermediate, Unlimited, SP-SFD and SP-FA/LV exams. A practice test built on another edition will give you wrong section numbers.
How close are practice questions to the real exam?
Live exam questions aren't published, and the handbook's samples won't appear on the exam. Good practice matches the format: multiple choice, open book and timed. For the NC exam, aim to finish 100 questions in under 6 hours.
Practice with 500+ more exam questions
JCR's $495 NC self-study package includes a 500+ question mock exam, on paper and digital, plus video lessons and a workbook. Videos and digital practice exams open right after purchase, and the workbook ships the same business day.
Give it 6–8 weeks, about an hour a night. Testing in North Carolina and want a teacher? JCR's two-day NC workshop has a 93% pass rate for JCR classroom students. Take it in person for $845, or live on Zoom.
Choose your state's self-study package
Each package is built for that state's exam and NEC edition. Pick yours:
Not sure which exam you need? See your state's license and exam requirements.
Related guides: The 5 most-missed NEC mock exam questions · 2017 NEC practice test · NEC adoption by state
More worked examples: all NEC Answers.
Sources JCR checked
- NCBEEC Examination Information Handbook (July 2026)
- NCBEEC: Examinations
- NFPA 70, National Electrical Code
JCR checked the topic counts against the NCBEEC handbook and each answer against its full JCR post on October 14, 2026.