ICC R18 Residential Electrician Exam (2023 NEC) Practice Exam
Free Practice Exam
Test your knowledge with 10 questions from our pool of 20 free questions.
- 10 questions per attempt
- 30 minute time limit
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Full Practice Exam
Complete exam simulation matching the real Pearson VUE test format.
- 60 questions (same as real exam)
- 180 minute time limit
- 7 topic areas covered
- 262 questions in pool
- Detailed explanations
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ICC R18 Residential Electrician (2023 NEC) Practice Exam Guide
What's on the exam
Questions per topic, out of 60This practice exam follows the official content outline for the ICC R18 Residential Electrician (2023 NEC) exam: General Knowledge, Services and Service Equipment, Feeders, Branch Circuits and Conductors, Wiring Methods and Materials, Equipment and Devices, Special Occupancies, Equipment, and Conditions.
You can practice two ways. The free practice exam gives you 10 questions per attempt, and you can retake it whenever you like. The full practice exam gives you 60 questions on a 3 hours clock, with a new draw from our question bank each attempt.
General Knowledge 7 items
Our study plan for this topic: Electrical Theory and General Electrical Load Calculations; Code Definitions and Terms; NEC Purpose, Scope, and Code Arrangement; Series, Parallel, and Combination Circuit Analysis; AC Circuit Properties: Impedance, Reactance, Inductance, and Capacitance; Power Factor, Apparent Power (kVA), and Power Factor Correction; Dwelling Unit Load Calculations (Lighting, Small-Appliance, Laundry, Cooking, and Dryer Loads); Feeder and Service Load Calculations with Demand Factors.
Services and Service Equipment 13 items
Our study plan for this topic: Service Load Calculations; Service Equipment & Service Conductors; System Grounding and Bonding; Service Disconnect Requirements and Ratings; Overcurrent Protection for Services; Grounding Electrode System and Electrode Types; Surge Protection Requirements for Services; Service Conductor Installation Methods and Clearances.
Feeders 8 items
Our study plan for this topic: Load Calculations; Equipment Grounding; Feeder conductor ampacity and minimum sizing (NEC 215.2); Overcurrent protection for feeders (NEC 215.3); Feeder disconnecting means for separate buildings and structures (NEC 225.31–225.39); Neutral conductor sizing for feeders (NEC 215.2(B), 220.61); Common neutral conductors and parallel feeder installations (NEC 215.4); Surge-protective device requirements for feeders supplying dwelling units (NEC 215.18, 225.42).
Branch Circuits and Conductors 15 items
Our study plan for this topic: Branch Circuit Calculations; Required Outlets & GFCI/AFCI Protection; Overcurrent Protection; Equipment Grounding; Conductors; Voltage Drop Calculations and Conductor Sizing; Conductor Ampacity Tables and Temperature Ratings; Ampacity Correction and Adjustment Factors.
Wiring Methods and Materials 8 items
Our study plan for this topic: Raceway Installations; Boxes and Enclosures; Flexible Cords and Cables; Cable Wiring Methods (NM, MC, SE, USE, UF) — Uses Permitted and Prohibited; Protection of Cables and Raceways Against Physical Damage; Conductor Fill and Conduit Sizing Calculations; Underground Installation Requirements and Minimum Cover Depths; Conduit Bending Techniques and Calculations.
Equipment and Devices 5 items
Our study plan for this topic: Luminaires; Receptacles, Switches and Other Devices; Appliances and Other Equipment; Luminaire location requirements (wet, damp, closets, bathtub/shower zones); Recessed luminaire installation (Type IC, clearances, thermal protection); Lighting track installation and construction requirements; Low-voltage lighting system requirements and voltage limitations; Switch ratings, types, and connection requirements.
Special Occupancies, Equipment, and Conditions 4 items
Our study plan for this topic: Swimming Pools and Similar Installations; Low Voltage Circuits, Alarm & Similar Systems; Fire Alarm Circuit Types: Power-Limited (PLFA) vs. Non-Power-Limited (NPLFA); Fire Alarm Circuit Power Source Requirements and Branch Circuit Protection; Separation and Mixing Rules for Fire Alarm Conductors and Other Circuit Types; Fire Alarm Cable Types, Listings, and Application Requirements (FPLP, FPLR, FPL, NPLFP, etc.); Class 2 and Class 3 Power-Limited Circuit Wiring Methods and Power Source Requirements; Communications System Grounding, Bonding, and Primary Protector Requirements.
Sample 1 — Branch Circuits and Conductors
Question: Ampacity tables for bare or covered conductors in free air are based on what ambient temperature?
- A. 50°C (122°F)
- B. 30°C (86°F)
- C. 25°C (77°F)
- D. 40°C (104°F)
Correct Answer: D
Per NEC 310.21, the ampacities for bare or covered conductors in free air are based on a 40°C (104°F) ambient temperature, with a total conductor temperature of 80°C and a wind velocity of 610 mm/sec (2 ft/sec).
Reference: NEC 2023 Section 310.21
Sample 2 — Services and Service Equipment
Question: A 400 A service uses 600 kcmil copper service conductors. What is the minimum size of a copper grounding electrode conductor that runs only to a concrete-encased electrode?
- A. 2 AWG
- B. 4 AWG
- C. 3/0 AWG
- D. 1/0 AWG
Correct Answer: B
Table 250.66 would require a 1/0 AWG copper grounding electrode conductor for 600 kcmil copper service conductors, but 250.66(B) says a grounding electrode conductor (or bonding jumper) that runs only to a concrete-encased electrode is not required to be larger than 4 AWG copper. So the minimum size required here is 4 AWG copper.
Reference: NEC 2023 Section 250.66(B), Table 250.66
Sample 3 — Feeders
Question: You are installing a feeder to a detached garage on a residential property. What is the minimum size for open individual overhead copper conductors spanning up to 50 feet?
- A. 10 AWG
- B. 12 AWG
- C. 14 AWG
- D. 8 AWG
Correct Answer: A
Per NEC 225.6(A), open individual conductors shall not be smaller than 10 AWG copper or 8 AWG aluminum for spans up to 15 m (50 ft) in length. For longer spans, 8 AWG copper or 6 AWG aluminum is required unless supported by a messenger wire.
Reference: NEC 2023 Section 225.6(A)
Your first attempt tells you where you're starting from. After every attempt, the results page shows your score for each outline topic, so you can see what to study next. Compare your score with the real exam's passing score, 70% correct, and keep going until you pass consistently.
- Answer the questions you know first, and bookmark the rest. Our practice exams let you bookmark and come back.
- Return to your bookmarks on the second pass.
- Keep a steady pace. The real exam works out to about 3 minutes per question.
- After each attempt, look up each missed question's reference and read the section.
| Questions | 60 questions |
| Time limit | 3 hours |
| Passing score | 70% correct |
| Books in the exam room | Open book |
| Exam fee | $120 |
- Results for examinations taken electronically are available immediately after the examination is completed.
- You must wait 10 days before retaking a failed exam.
Source: National Contractor/Trades Examination Information Bulletin, PUBLISHED June 30, 2026; ICC Exam Catalog, checked September 27, 2026. Check the bulletin before test day: fees and rules can change.