Mississippi Residential Electrician Practice Exam
Free Practice Exam
Test your knowledge with 10 questions from our pool of 25 free questions.
- 10 questions per attempt
- 30 minute time limit
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- A new mix each time
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Full Practice Exam
Complete exam simulation matching the real PSI test format.
- 60 questions (same as real exam)
- 180 minute time limit
- 9 topic areas covered
- 543 questions in pool
- Detailed explanations
Texts preferred · 9am–9pm Central
Mississippi Residential Electrician Practice Exam
What's on the exam
Questions per topic, out of 60The Mississippi Residential Electrician exam is 60 questions, 180 minutes, 70% to pass. That gives you three minutes per question — tight enough that hesitation on calculation problems will cost you.
Free practice exam: 10 questions per attempt, drawn from a limited pool. You can retake it as many times as you want. Use it to learn the format and see what style of question to expect before you commit to serious prep.
Full practice exam: 60 questions, 180-minute timer — same structure as the real thing. Every attempt pulls from a pool of 543 questions, so you won't see the same exam twice. Questions cover the subject areas tested on this exam. This is the tool to use when you need to know whether you're actually ready.
Start with the free exam. If you score well, great. If you don't, you'll know exactly what you're up against.
Services, Feeders, and Branch Circuits — 15 items (25% of exam)
This is the heaviest topic. Expect conduit fill calculations like the sample question below, conductor sizing for service entrance, service clearances for overhead and underground runs, and full load calculations using demand factors. You need to know how to size feeders, apply overcurrent protection, and work through branch-circuit, feeder, and service load calculations step by step. Per NEC 2020, Section 220.82(B) and Section 220.87, you'll be calculating residential loads using optional calculation methods. Know the difference between a feeder and a branch circuit cold — the exam doesn't define terms for you.
General Electrical Knowledge — 13 items (22% of exam)
GFCI and AFCI protection locations are heavily tested here. You need to know exactly which locations in a dwelling unit require GFCI under NEC 2020, Section 210.8(A)(6), and which branch circuits require AFCI protection under NEC 2020, Section 210.12(A). Branch circuit conductor sizing, voltage limitations under NEC 2020, Section 210.6(A), and standard overcurrent device ratings — including the next-size-up rule — are all fair game. Grounding and bonding basics also appear in this topic, with electrode types and system requirements.
Grounding and Bonding — 6 items (10% of exam)
This topic goes deeper than the basics in General Knowledge. Know your grounding electrode types and installation requirements. Understand how to size grounding electrode conductors and equipment grounding conductors. NEC 2020, Section 250.24(B) and Section 250.24(C) govern service grounding — know them. Main bonding jumper requirements, bonding of piping systems and structural metal, and what constitutes an effective ground-fault current path per NEC 2020, Section 250.4(A)(5) are all tested here.
Conductors and Cables — 5 items (8% of exam)
Table work. You need to pull ampacity values from conductor tables and then apply correction factors for ambient temperature and adjustment factors when more than three current-carrying conductors share a raceway. Know insulation designations — THHN, THWN, USE, XHHW — and which are rated for wet, damp, dry, direct burial, or sunlight exposure per NEC 2020, Section 310.8(B)(1). Parallel conductor rules under NEC 2020, Section 310.10(G)(1) — equal length, same material, same insulation — are a common question type.
Overcurrent Protection — 5 items (8% of exam)
Standard ampere ratings, tap conductor rules and length limits, and ground-fault protection of equipment requirements. NEC 2020, Section 240.13 and Section 240.86(C) both appear in the question bank. Know where overcurrent devices must be located in a dwelling and what the circuit breaker marking and arc energy reduction requirements mean in practice. NEC 2020, Section 240.67(A) and (B) cover arc flash requirements for fuses — know that section.
Raceways and Boxes — 4 items (7% of exam)
Conduit fill percentages, the four-quarter-bend limit per run, and box fill calculations. Know the securing and support intervals for EMT, IMC, RMC, FMC, and PVC. Pull box sizing — straight pulls versus angle pulls — uses NEC 2020, Section 314.28(A)(1) and Section 314.28(A)(2). These are calculation questions. Practice the math.
Lighting — 4 items (7% of exam)
Luminaire installation by location — wet, damp, corrosive, clothes closet clearances, and bathtub/shower zone restrictions. Recessed luminaire clearance from insulation: know the difference between Type IC and non-IC ratings per NEC 2020, Section 410.116(A)(1). Lighting track prohibited locations and connected load rules appear here as well.
Specialty — 4 items (7% of exam)
Pools, spas, hot tubs, and fountains. Know receptacle and lighting clearance distances from water's edge. Equipotential bonding requirements for permanently installed pools are tested directly. NEC 2020, Section 680.51(B) covers underwater luminaires. Disconnecting means requirements for pool and spa equipment are a recurring question type.
Safety — 4 items (7% of exam)
OSHA 29 CFR 1926 governs most of this topic. Know lockout/tagout procedures, PPE requirements for electrical work — rubber insulating gloves, sleeves, blankets, head protection — and working clearance requirements around energized equipment. Per 29 CFR 1926, Subpart K, §1926.403(i)(1)(i), Table K-1, minimum clearance distances from live parts depend on voltage. Know how to guard live parts operating at 50 volts or more.
Question 1 — Services, Feeders, and Branch Circuits
A 200A service uses (3) 3/0 THHN conductors and (1) 4 AWG grounding conductor in EMT. What is the minimum conduit size?
- A. 1-1/2"
- B. 2"
- C. 2-1/2"
- D. 3"
Correct Answer: B — 2"
Using NEC Chapter 9, Table 4 (conduit dimensions) and Table 5 (conductor cross-sectional areas), add up the total area for three 3/0 THHN conductors plus one 4 AWG THHN conductor. At 40% fill for four or more conductors, a 2" EMT raceway accommodates that conductor bundle. A 1-1/2" conduit falls short. A 2-1/2" conduit is legal but oversized — the question asks for minimum. Know how to work this calculation forward from conductor areas, not backward from a guess.
Question 2 — General Electrical Knowledge
What is the minimum disconnect ampacity for a 10 HP motor with a full-load current of 28A?
- A. 30A
- B. 40A
- C. 50A
- D. 60A
Correct Answer: B — 40A
NEC 2020, Section 430.110 requires the disconnecting means to be rated at no less than 115% of the motor's full-load current. 28A × 1.15 = 32.2A. You then round up to the next standard ampere rating — which is 40A, not 35A. This is a two-step calculation. Candidates who stop at 32.2A and pick 35A get this wrong because 35A is not a standard rating under the NEC's listed ampere ratings. Know the standard ratings cold.
Question 3 — Grounding and Bonding
At what service ampere rating is ground-fault protection of equipment (GFPE) required for solidly grounded wye systems operating at more than 150V to ground but not more than 600V phase-to-phase?
- A. 600A
- B. 800A
- C. 1000A
- D. 1200A
Correct Answer: C — 1000A
NEC 2020, Section 230.95 (referenced as NEC 230.95 in the question bank) sets this threshold at 1000A. Services below that rating are not required to have GFPE. The voltage condition matters too — this rule applies to solidly grounded wye systems above 150V to ground. Read the full condition before picking an answer.
Passing is 70% — that's 42 correct out of 60 on the real exam.
Your first practice score is a diagnostic. If you score 55% on the first attempt, that tells you where the gaps are, not that you'll fail the real exam. Use the topic breakdown after each attempt. If you're dropping points on Services, Feeders, and Branch Circuits — the 15-item topic — fixing that one area has more impact than drilling a 4-item topic you already know.
Scoring 70–75% on practice consistently is passing, but it's thin margin. A bad day, a misread question, or running out of time on a calculation problem drops you below the line. Aim for 80%+ on practice before you schedule the real exam. If you're scoring below 70% on the full 60-question practice exam, don't book the test yet. Use the free exam to warm up your sessions, then run full timed attempts on the paid exam to build the stamina the 180-minute format demands.
Stopping one step short on calculations. The motor disconnect question above is a perfect example. Candidates get the 115% multiplication right, then pick an answer that isn't a standard ampere rating. On Services, Feeders, and Branch Circuits questions, the same thing happens with load calculations — the math is right, but the demand factor application gets skipped.
Wrong table. Conductors and Cables questions require you to pull from the right ampacity table for the right temperature rating. Using the 75°C column when the question specifies 60°C terminations costs you the point. NEC 2020, Section 110.14(C)(1)(b) controls termination temperature ratings — know when it applies.
Misidentifying GFCI vs. AFCI requirements. The exam asks about specific locations. Candidates mix up which locations require GFCI under NEC 2020, Section 210.8(A)(6) versus which circuits require AFCI under NEC 2020, Section 210.12(A). These are tested separately. Know the location lists.
OSHA Safety questions treated as filler. Four items from 29 CFR 1926 — particularly Subpart K and Subpart V — cover lockout/tagout, PPE, and working clearances. Candidates underprep these because they feel like common sense. The exam asks for specific requirements: voltage thresholds, clearance distances, and specific PPE classifications per 29 CFR 1926, Subpart K, §1926.403(i)(1)(i), Table K-1. Study them like code sections, not instinct.
Running out of time on conduit fill and box fill. These are multi-step problems in Raceways and Boxes. If you haven't practiced the fill table workflow until it's fast, three minutes per question disappears quickly.
| Item | Detail |
|---|---|
| Total Questions | 60 |
| Time Limit | 180 minutes |
| Passing Score | 70% (42 correct) |
| Number of Topic Areas | 9 |
| Heaviest Topic | Services, Feeders, and Branch Circuits (15 items) |
| Practice Pool (Full Exam) | 543 questions |
| Free Exam | 10 questions per attempt |