Start Practice Test

Oklahoma Residential Electrical Journeyman — Practice Exam

What This Practice Exam Covers

The Oklahoma Residential Electrical Journeyman licensing exam consists of 80 questions with a 210-minute time limit. You need a 70% (56/80) to pass. The exam spans 12 topic areas, from NEC code fundamentals and electrical theory through grounding, raceways, hazardous locations, and jobsite safety.

This practice exam offers two options:

• Free practice exam: 10 questions per attempt drawn from a limited pool. You can retake it as many times as you like to get a feel for the question format and style before committing to full prep.
• Full practice exam: Mirrors the real exam — 80 questions, 210-minute time limit, drawn from a pool of 394+ questions so every attempt delivers a unique set. No duplicate exams. Questions are built around the exact topic breakdown provided by the official test provider.

Start with the free exam to gauge where you stand, then use the full exam for serious preparation.

What You'll Be Tested On

General Knowledge (4 items) covers NEC structure before you ever touch a wire. Expect questions on the purpose and scope of the code (practical safeguarding of persons and property), how Chapters 1–9 and Annexes are arranged, and the critical difference between mandatory language (shall/shall not) versus permissive language (shall be permitted) under Article 90.5(A). You also need to know what authority the AHJ holds and when special permission applies. Common field slang versus official NEC terminology is a real test item — know both.

General Electrical Knowledge (12 items) is the heaviest calculation topic. Ohm's Law, series/parallel circuits, and voltage drop calculations appear in multiple question forms. The three-phase horsepower formula — HP = (E × I × %EFF × PF × 1.73) / 746 — is explicitly tested, as are kW and kVA formulas. Per NEC 2023, Article 220 and Ugly's Electrical References, you must distinguish single-phase from three-phase formulas instantly. Conductor ampacity tables and both ambient temperature correction factors and bundling adjustment factors (from NEC 2023, Section 310.15(B)(1), Table 310.15(B)(1)(1), Section 310.15(C)(1), Table 310.15(C)(1)) require careful step-by-step application.

Electrical Installation Requirements (10 items) tests cable types (NM, MC, AC, MI, SE, USE, UF), their insulation ratings, securing and support rules, and nail/screw protection under NEC, Section 300.4(A)(1), 300.4(A)(2), and 300.4(D). Underground burial depths and box fill calculations are frequent multi-step problems. Know your conductor volume allowances from NEC, Table 314.16(B) cold.

Services, Feeders, and Branch Circuits (10 items) includes load calculations for dwellings using both the standard and optional methods, demand factors for lighting, appliances, cooking equipment (NEC 2023, Section 220.55, Table 220.55), and dryers (NEC 2023, Section 220.54). GFCI and AFCI protection locations are high-frequency items. Branch circuit sizing for continuous loads — 125% rule from NEC 210.20(A) — appears in scenario-based questions. Service entrance clearances come from NEC, Section 230.24(A) and related sections.

Overcurrent Protection (8 items) requires knowing standard ampere ratings from NEC 2023, Section 240.6(A) and tap rules from NEC 2023, Section 240.21(B)(1), 240.21(B)(2), 240.21(B)(3), and 240.21(B)(4) — the 10-ft, 25-ft, and outside tap rules are individually tested. Fuse types (plug, Type S, Edison-base, cartridge) and circuit breaker marking/rating requirements appear, as does motor branch-circuit protection using NEC 2023, Table 430.52.

Grounding and Bonding (8 items) covers the grounding electrode system under NEC, Section 250.50 and 250.52, electrode conductor sizing via NEC, Section 250.66(A) and 250.66(B), equipment grounding conductor sizing from NEC, Table 250.122, and bonding of piping systems under NEC, Section 250.104(A)(1) and 250.104(B). Main bonding jumper sizing and separately derived system grounding rules are tested at the calculation level, not just recognition.

Conductors and Cables (4 items) focuses on insulation type designations — THHN, THWN, RHW, XHHW — including maximum operating temperatures and whether they're rated for dry, damp, or wet locations. Parallel conductor requirements and single-phase dwelling service sizing appear here.

Raceways and Boxes (6 items) tests box fill calculations using conductor volume allowances, conduit fill percentages from NEC, Chapter 9, Table 1, and pull/junction box sizing formulas for straight and angle pulls from NEC, Section 314.28(A)(1) and 314.28(A)(2). Know the securing and support intervals for EMT, RMC, and flexible conduit types.

Special Occupancies and Equipment (8 items) covers hazardous location Class/Division/Group classification (NEC, Section 500.5, 500.6), sealing requirements in Class I locations under NEC, Section 501.15(A)(1), swimming pool bonding and GFCI rules, health care facility grounding under NEC, Section 517.16(A) and 517.18(B)(1), and A/C equipment disconnecting means from NEC, Section 440.64.

Low Voltage, Alarms, Signaling, and Communications (4 items) tests fire alarm circuit types (NPLFA vs. PLFA), cable ratings (FPLP, FPLR, FPL) per NEC, Section 760.53 and Table 760.154, separation requirements under NEC, Section 760.136(D), and communications cable substitution hierarchy (CMP, CMR, CMG, CM, CMX) from NEC, Section 800.179. Antenna system grounding per NEC, Section 810.21(H) also appears.

Lighting and Signs (4 items) covers luminaire location restrictions (wet, damp, clothes closets, bathtub/shower zones) from NEC, Section 410.10(A) and 410.10(D), recessed luminaire clearances and Type IC ratings per NEC Handbook, Section 410.116(A)(1) and 410.116(B), lighting track restrictions, and sign disconnecting means from NEC Handbook, Section 600.5(A).

Safety (2 items) draws from OSHA 29 CFR 1926 — lockout/tagout procedures, arc-flash PPE categories, shock protection boundaries, and rubber insulating equipment requirements under 29 CFR 1926, §1926.97(c)(2)(ii). Two questions means every point counts here.

Worked Sample Questions

Question 1 — Three-Phase Horsepower Formula

When calculating horsepower for a three-phase motor, which formula is correct?

• A. HP = (E × I × %EFF × PF) / 746
• B. HP = (E × I × %EFF × PF × 2) / 746
• C. HP = (E × I × %EFF) / 746
• D. HP = (E × I × %EFF × PF × 1.73) / 746

Correct Answer: D

The √3 multiplier (1.73) is mandatory for any three-phase calculation — it accounts for the phase relationship between the three voltage waveforms. Option A is the correct single-phase formula; Option B incorrectly uses 2 (a two-phase multiplier that doesn't apply here); Option C drops both PF and the phase multiplier. On the exam, these four options test whether you can distinguish single-phase from three-phase formulas under pressure. Source: NEC 2023, Article 430 (Motors); Ugly's Electrical References, To Find Horsepower, p. 20

Question 2 — Cable Protection from Framing Members

Where a cable-type wiring method is installed parallel to framing members such as studs or joists, the nearest outside surface of the cable must be not less than ______ from the nearest edge of the framing member where nails or screws are likely to penetrate.

• A. 3/4 inch
• B. 1 inch
• C. 1-1/4 inches
• D. 1-1/2 inches

Correct Answer: C

NEC, Section 300.4(D) requires 1-1/4 inches (32 mm) of clearance between the cable's outer surface and the nearest edge of a framing member where fasteners could penetrate. The 3/4-inch and 1-inch distractors are plausible but wrong; 1-1/2 inches overstates the requirement. If the clearance can't be maintained, a listed steel plate of adequate thickness is required instead. This rule catches many candidates who confuse it with the through-bored hole requirement.

Question 3 — Continuous Load Overcurrent Device Sizing

A residential wireman installs a circuit for outdoor holiday lighting that will run continuously for more than three hours. The continuous load is 12 amperes; there is no noncontinuous load. What is the minimum rating of the overcurrent device?

• A. 20 amperes
• B. 25 amperes
• C. 15 amperes
• D. 12 amperes

Correct Answer: C

Per NEC 210.20(A), the overcurrent device must be rated at least 125% of the continuous load plus 100% of any noncontinuous load. Calculation: 12 A × 1.25 = 15 A. Since 15 A is a standard rating listed in NEC 2023, Section 240.6(A), a 15-ampere breaker or fuse satisfies the requirement. Option A (20 A) is the next standard size up — not the minimum. Option D (12 A) ignores the 125% continuous load rule entirely.

How to Read Your Score

Passing requires 70% — 56 correct out of 80. On your first practice attempt, treat your score as a diagnostic, not a final judgment. A first attempt reveals which of the 12 topic areas are already solid and which need focused work before exam day.

If you score well below 70%, identify the two or three topics where you lost the most points and work those first — General Electrical Knowledge (12 items) and Services, Feeders, and Branch Circuits (10 items) together represent 27.5% of the real exam, so gains there move your score the most. If you score between 65–75%, you're close but not safe — one bad topic can sink an otherwise decent performance. Candidates who routinely score 80%+ on the full practice exam with its 394+ question pool are in a much stronger position because they've seen varied question phrasing, not just repeated items from a small pool.

Use the free exam to get comfortable with format and pacing. Use the full practice exam repeatedly, using each attempt's topic breakdown to prioritize what to study next.

Where Candidates Lose Points

Multi-step calculation errors sink more candidates than any single topic. Voltage drop, box fill, and load calculation questions each require you to complete every step correctly — skipping the 125% multiplier on a continuous load or misreading a temperature correction table turns a right approach into a wrong answer.

Wrong table or code section: Ampacity questions require selecting the correct table — Table 310.16 for conductors in raceways versus free-air tables — and then applying both the ambient temperature correction factor and the bundling adjustment factor if both apply. Applying only one when both are required is a common and costly mistake.

Three-phase vs. single-phase formula confusion in General Electrical Knowledge: missing the 1.73 multiplier or misapplying it to kW versus kVA formulas costs points on what should be straightforward calculations.

Grounding and bonding details: Candidates often mix up grounding electrode conductor sizing rules (NEC, Section 250.66(A) and 250.66(B)) with equipment grounding conductor sizing from NEC, Table 250.122. These are separate tables with separate triggers.

Tap rule specifics: The 10-ft, 25-ft, and outside tap rules under NEC 2023, Section 240.21(B)(1) through 240.21(B)(4) each have distinct conditions. Confusing which rule applies to which scenario — especially conductor size versus load requirements — is a recurring point of failure.

Time management: At 210 minutes for 80 questions, you have about 2.6 minutes per question. Calculation-heavy sections like General Electrical Knowledge and Overcurrent Protection can eat into time needed for straightforward code recall questions later.

Exam Quick Facts