Oklahoma Limited Electrical Contractor

Oklahoma Limited Electrical Contractor Exam: Complete 2026 Study Guide

You've put in the work on job sites. Now it's time to prove it on paper. The Oklahoma Limited Electrical Contractor exam is the gateway to operating legally as an electrical contractor in the state — and passing it opens the door to running your own business, bidding jobs, and growing your career. This guide breaks down everything you need to know: exam format, the topics covered, sample questions, and the study materials that will give you the best shot at clearing that 70% passing mark. Start building your prep plan today, and consider taking a free practice exam to see where you stand right now.

Oklahoma Limited Electrical Contractor Exam Overview

The Oklahoma Limited Electrical Contractor exam is administered by PSI Exams. Here's what to expect when you sit down on test day:

• Questions: 100 scored questions
• Time limit: 240 minutes (4 hours)
• Passing score: 70% — meaning you need 70 correct answers out of 100
• Format: Multiple-choice
• Where to register: exam registration page

The Oklahoma PSI Electrical Exam is a closed-book, proctored test. You won't have internet access, but you will be given a non-programmable calculator. Four hours sounds like a lot, but the exam covers serious depth across 13 topic areas — time management matters. Check the official exam bulletin before your test date to confirm any last-minute changes to procedures or reference materials.

Topics Covered on the Oklahoma Contractors License Exam

The exam spans 13 topic areas drawn from the NEC, OSHA standards, and general electrical knowledge. Here's how the 100 scored questions break down:

Where to focus: Grounding and Bonding, Conductors and Cables, Special Occupancies, and Low Voltage systems each carry 10 questions — that's 40% of your score right there. Raceways and Boxes (9 items) and Safety (8 items) are close behind. Nail those six topic areas and you're a long way toward a passing score.

Sample Questions

Here are five questions representative of what you'll see on the Oklahoma limited electrical contractor practice test. Work through them — but we're not giving away the answers here. Take our free practice exam to check your thinking.

Question 1 — Conductors and Cables (Medium)

Insulated conductors and cables used in wet locations must comply with which of the following requirements?

• A) Be any type identified in the Code for dry locations
• B) Be installed only in rigid metal conduit to prevent moisture infiltration
• C) Have a minimum insulation rating of 90°C regardless of conductor type
• D) Be moisture-impervious metal-sheathed, be a type listed for wet locations, or be one of the specifically designated wet-location conductor types

Question 2 — Services, Feeders, and Branch Circuits (Medium)

According to the NEC, what is the recommended maximum voltage drop for branch circuits at the farthest outlet of power, heating, and lighting loads?

• A) 2 percent
• B) 3 percent
• C) 5 percent
• D) 10 percent

Question 3 — Electrical Installation Requirements (Medium)

A project engineer asks you to install cables through bored holes in wood joists for a branch circuit. What is the minimum distance the edge of the bored hole must be from the nearest edge of the wood member to avoid requiring a steel plate for protection?

• A) 25 mm (1 in.)
• B) 32 mm (1¼ in.)
• C) 38 mm (1½ in.)
• D) 50 mm (2 in.)

Question 4 — General Electrical Knowledge (Easy)

In a series circuit with three resistors of 20 ohms, 25 ohms, and 15 ohms, what is the total resistance of the circuit?

• A) 15 ohms
• B) 20 ohms
• C) 60 ohms
• D) 45 ohms

Question 5 — Safety (Easy)

According to OSHA sanitation requirements, what is the minimum number of toilet facilities required for a construction job site with 20 or fewer employees?

• A) 2
• B) 1
• C) 3
• D) 1 toilet seat and 1 urinal

Know the answers? Head to our free practice exam and put yourself to the test.

What Types of Questions to Expect

Our full practice bank has 595 questions covering all 13 exam topics. Here's what each area actually tests:

• General Knowledge (25 practice questions): Permits, inspections, structural integrity during installation, and reading a job to estimate material and labor needs.
• General Electrical Knowledge (50 practice questions): Ohm's Law calculations, series/parallel/combination circuits, power and heat-loss formulas, AC theory, and three-phase fundamentals.
• Electrical Installation Requirements (50 practice questions): NEC-approved methods for standard and high-voltage (over 600V) installations — bored holes, cable protection, clearances, and more.
• Services, Feeders, and Branch Circuits (50 practice questions): Service entrance rules, voltage drop calculations, outside branch circuits, feeders, and high-voltage service requirements.
• Overcurrent Protection (45 practice questions): Selecting and sizing fuses and breakers per NEC requirements across circuit types.
• Grounding and Bonding (50 practice questions): General grounding rules, sizing grounding electrode conductors, and selecting equipment grounding conductors.
• Conductors and Cables (50 practice questions): Underground installations, vertical conductor requirements, conductor selection, armored cable (Type AC), and metal-clad cable (Type MC).
• Raceways and Boxes (50 practice questions): Raceway sizing and fill rules, box fill calculations, pull box sizing, conduit fittings, and rigid metal conduit (RMC) requirements.
• Special Occupancies and Equipment (63 practice questions): Hazardous location wiring (Class I, II, III), commercial garages, fuel dispensing, bulk storage plants, spray areas, health care facilities, places of assembly, and swimming pools.
• Low Voltage, Alarms, Signaling Systems, and Communications (48 practice questions): Remote control and signaling circuits, communication circuits, circuits operating at 50 volts or less, fiber optics, and photovoltaic systems.
• Lighting and Signs (34 practice questions): Fixture installation methods, grounding requirements, fixture wiring, fluorescent fixture rules, and construction standards for luminaires.
• Safety (50 practice questions): OSHA job site sanitation, PPE responsibilities, excavation safety, emergency action plans, and safety training requirements.
• Motors and Transformers (30 practice questions): Residential motor circuits, commercial and industrial motor branch circuits, feeder transformer sizing, and transformer applications.

Study Materials

These are the books you'll need — both required references and tools to make your study sessions more efficient.

Required References

• NEC 2023 — The National Electrical Code is the backbone of this exam. Most questions trace back to NEC articles. Get this book, study it, and know where to find answers fast.
• OSHA 29 CFR 1926 — The Safety section pulls directly from OSHA's construction industry standards. This book covers everything from sanitation to excavation requirements.
• Ugly's Electrical References 2020 — A compact, field-proven quick-reference guide. Great for reinforcing wire sizing, conduit fill tables, and electrical formulas without flipping through the full NEC.

Study Tools That Actually Help

• Redi-Tag Permanent Colored Tabs — Tab your NEC and OSHA books by topic. Color-coded tabs let you jump straight to the relevant article during study sessions. These tabs are permanent and laser-printable, so they stay put through heavy use.
• Sharpie Highlighters — Mark key definitions, exception text, and calculation rules as you study. The 12-pack gives you enough colors to code by topic area across multiple books. Let the ink dry before you highlight — the smear-resistant formula works best that way.
• Non-Programmable Calculator — You'll need one for the exam, so practice with the same type. This one has a clear 8-digit display and handles square roots and percentages — exactly what you need for voltage drop and power calculations.

Study Tips for the Oklahoma PSI Electrical Exam

Read the question, not the answer. A lot of test takers get tripped up by answer choices that are factually true but don't actually address what's being asked. Before you select anything, re-read the question and confirm your answer directly responds to it — not just that it's a correct electrical fact.

When two answers look equally right, read all four choices again. The exam is designed to test precision. One answer will be a better fit than the others. Slow down and find it.

There's no pattern in the answer key. If you've answered A, A, A, A — the next answer can absolutely be A again. Judge every question independently. Trying to "balance" your answers is a trap.

Every attempt is different. Whether you're taking our practice exam or sitting the real thing, the question mix and order will vary. What stays constant is the topic distribution outlined in the exam bulletin. Study the topics, not the questions.

Tab your NEC early. The exam is closed-book, but building the habit of knowing where things live in the Code makes the concepts stick faster during study.

Frequently Asked Questions

How many questions are on the Oklahoma Limited Electrical Contractor exam?
The exam has 100 scored questions. You have 240 minutes to complete them.

What score do I need to pass?
You need 70% — that's 70 correct answers out of 100. Missing 30 questions and still passing gives you some room for error, but don't count on it. Aim for 80%+ in practice.

Where do I register for the exam?
Through PSI Exams at the exam registration page. You can also find general licensing information on the state licensing website.

What's the best way to prepare for the electrical practice exam?
Start with the free tier to get comfortable with the format, then move to the full practice exam. The full version mirrors the real exam — 100 questions, 240 minutes, same topic weighting — and draws from a large question pool so each attempt is genuinely different. Use the topic score breakdown to find weak areas and study those specifically.

Can I use a calculator on the exam?
Yes — a non-programmable calculator is allowed. Practice with one so you're fast and accurate on voltage drop and power calculations.

Ready to Pass?

The Oklahoma Limited Electrical Contractor exam is thorough, but it's absolutely passable with the right preparation. Know your NEC, understand OSHA safety rules, and put real time into grounding, conductors, and special occupancies — those three topics alone account for 30 of your 100 questions. Use good study tools, tab your books, and practice under realistic conditions. Start today with our free practice exam — 10 questions, no account needed, no cost. When you're ready to go deeper, upgrade to the full 595-question bank and find out exactly where you need to focus before test day.