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Texas Residential Wireman Electrician — Practice Exam

What This Practice Exam Covers

The Texas Residential Wireman Electrician licensing exam is 80 questions with a 240-minute time limit. You need a 70% to pass — that's 56 correct answers.

This practice exam gives you two options:

Free practice exam — 10 questions per attempt, pulled from a limited pool. You can retake it as many times as you want. It's a solid way to get a feel for how the questions are written and what the exam actually demands before you commit to more.

Full practice exam — 80 questions, 240-minute timer, structured to mirror the real exam. Questions are drawn from a pool of 518+ items, so every attempt pulls a different mix. You won't see the same exam twice. Questions are built directly from the official exam topic breakdown, so you're practicing on the material that actually shows up.

Start with the free exam. If you're serious about passing, move to the full exam.

What You'll Be Tested On

Definitions, Calculations, Theory, and Plans — 8 questions
This section covers load calculations using demand factors, dwelling unit lighting and small appliance circuit loads, and the structure of the NEC itself — mandatory versus permissive rules, how the code is enforced, and who has authority. You'll also be tested on grounding electrode system types and sizing, overcurrent protection location and rating, and GFCI/AFCI requirements by location and occupancy. Don't skim the grounding electrode material — the resistance threshold for a single rod electrode (25 ohms) is a direct exam target.

Electrical Services, Service Equipment, and Separately Derived Systems — 16 questions
The heaviest-weighted topic on the exam. Expect questions on overhead and underground service conductor clearances, the service disconnecting means location and the six-disconnect maximum, service entrance conductor ampacity, and overcurrent and ground-fault protection requirements. Bonding and grounding of service equipment gets its own attention here — know the difference between grounding and bonding, not just the terms but what each requires physically.

Electrical Feeders — 7 questions
The 125% continuous load rule for feeder conductor ampacity is tested here alongside demand factors for dwelling, multifamily, and non-dwelling occupancies. You need to know feeder overcurrent protection ratings, ampacity correction and adjustment factors, ground-fault protection requirements for feeder disconnects rated 1,000 amperes or more, and surge-protective device requirements. Feeder tap rules — including conductor length limits and the fraction-of-overcurrent-device ampacity requirements — appear on this exam, as the sample question on this page shows.

Branch Circuit Calculations and Conductors — 14 questions
Second-largest topic by question count. Know NEC 210.19 and 210.20 cold — minimum conductor ampacity and overcurrent protection for continuous loads. GFCI protection by location (210.8) and AFCI protection for dwelling units (210.12) are both tested. You'll calculate lighting loads, small-appliance circuit loads, and cooking appliance loads. Know the permitted loads for 15A, 20A, 30A, and 50A circuits, and know which circuits are required in a dwelling unit and how many.

Electrical Wiring Methods and Electrical Materials — 10 questions
Conductor insulation ratings, ampacity tables, NM cable support intervals and securing requirements, underground cover depth requirements, and box fill calculations all show up here. Know Article 300.4 for physical protection of cables through framing members. Box fill is arithmetic — conductor count, fittings, devices, ground conductors — and the exam will test whether you can run the calculation correctly under a time constraint.

Electrical Equipment and Devices — 12 questions
Third-heaviest topic. Switch types and ratings, receptacle requirements (CO/ALR, tamper-resistant, weather-resistant, isolated ground), luminaire placement rules for wet and damp locations, clothes closets, and bathtub/shower zones. Panelboard installation and overcurrent protection rules. Motor branch-circuit conductor sizing and overload protection. Disconnecting means for motors, appliances, AC equipment, and generators. This section rewards candidates who have actually wired residential equipment and understand why the rules exist.

Motors and Generators — 2 questions
Small item count but specific content. Motor branch-circuit conductor sizing uses the 125% rule. Know Table 430.52 for maximum overcurrent device ratings. Understand locked-rotor code letters and what they tell you. The in-sight disconnecting means rule and the horsepower-rating requirement for controllers are the most commonly tested points here.

Electrical Control Devices and Disconnecting Means — 2 questions
Article 404 governs switches — connection requirements, grounded conductor rules, ratings, mounting height, and enclosure accessibility. Know when a circuit breaker can serve as a switch and when it cannot. Panelboard overcurrent protection requirements also appear here.

Special Occupancies, Equipment, and Conditions — 7 questions
Class I, II, and III hazardous locations. Division 1 versus Division 2. Material groups for Class I (A, B, C, D) and Class II (E, F, G). Permitted wiring methods for each division. Sealing requirements for conduit in hazardous locations. Temperature class (T codes) and equipment marking. This section is concept-heavy — you won't wire a grain elevator every day, but the exam tests whether you know the classification system.

Renewable Energy Technologies — 2 questions
Photovoltaic system requirements and electric vehicle charger installation rules. Two questions — know the basics of PV disconnecting means and EV charger circuit requirements.

Worked Sample Questions

Question 1 — Definitions, Calculations, Theory, and Plans

When a single rod, pipe, or plate grounding electrode is installed, under what condition is a supplemental electrode NOT required?

• A. When the electrode is driven below the permanent moisture level
• B. When the electrode has a resistance to earth of 25 ohms or less
• C. When the electrode is bonded to the metal water piping system
• D. When the electrode is located within 6 ft of the building foundation

Correct Answer: B

NEC 250.53(A)(2) Exception states that a supplemental electrode is not required when the single rod, pipe, or plate electrode measures 25 ohms or less resistance to earth. The other options describe conditions that may affect performance or bonding, but none of them eliminate the supplemental electrode requirement. The 25-ohm threshold is the specific number to memorize — not a range, not an approximate figure.

Question 2 — Special Occupancies, Equipment, and Conditions

True or False: Reconditioned transfer switches are permitted for use in emergency systems.

Correct Answer: False

NEC 700.2 prohibits reconditioned transfer switches in emergency systems outright. No exceptions. This is a direct code prohibition, and the exam tests it because candidates sometimes assume that equipment meeting original specifications can be reinstalled in any application.

Question 3 — Electrical Feeders

Feeder tap conductors not exceeding 10 ft in length that leave the enclosure or vault where the tap is made must have an ampacity of not less than what fraction of the rating of the overcurrent device protecting the feeder conductors?

• A. One-half
• B. One-third
• C. One-quarter
• D. One-tenth

Correct Answer: D

Per NEC 240.21(B)(1), when tap conductors of 10 feet or less leave an enclosure or vault, their ampacity must be at least one-tenth of the feeder overcurrent device rating. Candidates frequently guess one-third because that number appears elsewhere in the tap rules. The specific condition here — leaving an enclosure or vault — triggers the one-tenth requirement. Read the condition before you look at the fraction.

How to Read Your Score

70% is passing — 56 out of 80 questions correct.

Your first practice attempt is a diagnostic. It tells you where your knowledge gaps are, not whether you'll pass. A score in the 60s on your first try means you're in range but not ready. A score below 60 means you have specific sections that need real work before exam day.

Use the topic breakdown after each attempt. If you're dropping points on Branch Circuit Calculations and Conductors — the 14-question section — that costs you more than losing points on Motors and Generators at 2 questions. Fix your biggest gaps first.

Scoring near 70% on practice should make you cautious, not confident. The real exam has pressure the practice test doesn't. Aim to consistently score 80% or better on full practice attempts before you schedule your exam date. That buffer matters when a question on feeder tap fractions or hazardous location classifications catches you off guard.

Where Candidates Lose Points

Feeder and branch circuit calculations are where arithmetic errors stack up. Missing a demand factor, applying 125% to noncontinuous loads when it only applies to continuous loads, or pulling from the wrong ampacity table — each one costs a question.

GFCI and AFCI location requirements trip up candidates who know the general rule but not the specific location. Knowing that AFCI protection is required isn't enough — you need to know which rooms, which circuits, and which exceptions apply under Article 210.12.

Grounding versus bonding is a consistent problem. Candidates blur the two concepts and then misread questions that hinge on that distinction — particularly in the Services and Equipment topic, which carries 16 questions.

Hazardous location classification costs points for candidates who mix up Division 1 versus Division 2, or who apply the wrong material group to a scenario. This section requires memorization, not calculation.

Time management is real. At 240 minutes for 80 questions, you have 3 minutes per question. Multi-step calculations in the Branch Circuit and Feeder sections can eat that time fast if you're not efficient. Practice under the clock.

Exam Quick Facts