NEC Code Practice Tests

Article-by-article NEC code tests updated for the 2026 National Electrical Code edition.

25 tests · 281 questions · Free · No signup · NEC 2026
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Based on NEC 2026 (NFPA 70) & official state exam content outlines.  ·  Last reviewed Jun 2026

What Is the National Electrical Code (NEC)?

The National Electrical Code (NFPA 70) is the rulebook for all electrical installations in the United States. It is published by the National Fire Protection Association (NFPA) and updated every three years. The current edition is NEC 2026. Most states adopt the NEC as law — meaning any electrical work that violates the NEC is an illegal installation once your state has adopted that edition.

The NEC does not cover everything (utility company work and some industrial equipment are separate), but for residential, commercial, and most industrial electrical work, it is the primary standard. Every electrician licensing exam in the US is based on the NEC.

How the NEC Is Organized

Understanding the NEC structure helps you find answers faster on an open-book exam:

  • Chapters 1–4: General rules that apply to all electrical installations.
  • Chapters 5–7: Special rules for specific situations (hazardous locations, special equipment, emergency systems). These override Chapters 1–4 where they conflict.
  • Chapter 8: Communications wiring — stands completely alone, not subject to Chapters 1–7.
  • Chapter 9: Tables — referenced by the articles but not standalone enforceable rules.
  • Annexes A–J: Reference material, informational only, not enforceable.

Exam tip: Learn the NEC index — look up by keyword, not by article number. "Grounding electrode conductor" → index → Art. 250 page. This is how fast test takers find answers.

NEC 2026 Key Changes You Need to Know:
  • Art. 210.12: AFCI protection now required for nearly all 120V branch circuits in dwelling units — major expansion from NEC 2023.
  • Art. 210.17: Brand new — EV-ready outlet required in new single-family homes.
  • Art. 230.67: Surge protection required at service equipment for new installations.
  • Art. 625: EV charging station rules fully rewritten — now covers bidirectional (V2G) charging.
  • Art. 706: Energy storage systems (home batteries, commercial BESS) — significantly expanded rules.
Art. 100 Definitions Art. 210–250 Branch Circuits & Grounding Art. 300–358 Wiring Methods Art. 430 Motors Art. 700–702 Emergency Systems NEC 2026 Changes
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Wiring Methods Branch Circuits Motors
NEC 2026

NEC 2026 Practice Test - Arc-Energy Reduction (240.67 / 240.87)

Beginner

Practice test on the arc-energy reduction rules of the 2026 NEC. Covers when 240.67 (fuses) and 240.87 (circuit breakers) trigger, the seven approved reduction methods, documentation, and worker-exposure scope.

25 Q · 38 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Grounding and Bonding (NEC 250)

Advanced

Free online test on Grounding and bonding ( National Electrical Code - 250)

10 Q · 15 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Branch Circuits (NEC 210)

Beginner

Free online practice test on NEC code Questions (Branch Circuits)

10 Q · 15 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

NEC 240 — Overcurrent Protection Practice Test 1

Beginner

Free online NEC Article 240 overcurrent protection practice test. Covers conductor ampacity limits (14/12/10 AWG), standard OCPD ratings, the 10-foot and 25-foot tap rules, plug and cartridge fuse requirements, circuit breaker installation rules, and supplementary overcurrent protection. NEC 2023 edition — ideal for journeyman and master electrician exam preparation.

30 Q · 45 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Service Entrance , Branch circuits and feeder conductors-2

Intermediate

Service Entrance , Branch circuit conductors and Feeder conductor theory and practice test -2

11 Q · 17 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Dwelling Unit Calculations Practice Quiz - 1

Advanced

Free Online Practice Test on Single Family Dwelling Unit calculations - 1

10 Q · 15 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Motor circuit calculations (NEC 400)

Beginner

Free online nec code practice test ( Motor Circuit Calculations )

9 Q · 14 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

NEC 220 — Power System Load Calculations Practice Test 1

Beginner

Free online NEC Article 220 power system load calculations practice test. Covers single-phase and three-phase power calculations, apparent and reactive power, load factor, demand factor, power factor correction, voltage drop, transformer kVA sizing, NEC lighting unit loads (Table 220.42), small appliance circuits, range demand (Table 220.55), continuous load rules, and generator sizing. NEC 2023 edition.

30 Q · 45 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

NEC 500 hazardous locations

Advanced

Free online theory quiz test on hazardous locations (NEC 500)

8 Q · 12 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Flexible Cords and Fixture Wires (NEC 400)

Beginner

Free online practice test on Flexible Cords and Fixture Wires (NEC 400) objective questions.

8 Q · 12 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Wiring Methods (NEC 300) Practice Test

Intermediate

Free Online Practice Test on NEC(300) Wiring Methods

10 Q · 15 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Cabinets, Enclosures & Cutout Boxes (NEC 312/314)

Intermediate

Free practice NEC Code question and answers on Cabinets, enclosures, cutlet boxes.

11 Q · 17 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

NEC (310) Conductors General Wiring

Intermediate

Free online practice NEC Code Questions on NEC (310) Conductors General Wiring

1 Q · 10 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Protective Relay Objective Questions Quiz

Intermediate

Free online quiz on Protective Relay objective questions.

9 Q · 14 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Resistor Practice Quiz Questions

Intermediate

Free Online Resistor Quiz Questions

12 Q · 18 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Motor Circuit Calculations-2 (NEC 430)

Advanced

Free Online NEC Code Questions : Motor Circuit Calculations (NEC 430)

10 Q · 15 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Equipment for General Use Questions-1

Intermediate

Free NEC 400: Equipment For General Use Practice Questions-1

11 Q · 17 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Commercial load Calculations (NEC Code Questions)

Intermediate

Free NEC Code Questions and Answers ( Commercial Load Calculations)

9 Q · 14 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Voltage Drop Calculations (NEC Code Questions)

Intermediate

Free online practice test on Conductor Voltage Drop calculations.

10 Q · 15 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Motor Circuit Calculations -3 (NEC Code Questions)

Intermediate

Online Practice Test on Motor Circuit Calculations

10 Q · 15 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Transformer Calculations NEC code Questions

Advanced

Free Online Practice Test on Transformer Calculations

6 Q · 10 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Panel and Switch Board- NEC Code Questions

Beginner

Practice Questions on Panel and Switch Boards - NEC Code Questions

5 Q · 10 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Single family dwelling unit Practice Questions

Intermediate

NEC Code Questions : Single family dwelling unit calculations

9 Q · 14 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Over current Protection Practice Test Questions-2

Beginner

Take a Practice test on Over current Protection quiz questions - 2

10 Q · 15 min · 70% pass
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Wiring Methods Branch Circuits Motors
NEC 2023

Hazardous Locations practice test questions-1

Intermediate

Take a Practice test on Hazardous locations Practice quiz questions - 1

7 Q · 11 min · 70% pass
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Article-by-Article Study Guide

These are the major NEC articles and what each one governs. Use this as a study roadmap — start with the articles your exam tests most, then fill in the rest.

ArticleTopicKey Rules
100DefinitionsFeeder, branch circuit, OCPD, dwelling unit, accessible, identified
110General RequirementsWorking clearances, interrupting ratings, equipment approval
200Use and ID of Grounded ConductorsWhite/gray insulation, terminal identification
210Branch CircuitsCircuit ratings, GFCI, AFCI, outlet spacing, small appliance circuits
215FeedersFeeder conductor sizing and OCPD
220Branch/Feeder/Service CalculationsDwelling unit loads, demand factors, service sizing
225Outside Branch Circuits and FeedersOverhead and underground conductors outside a building
230ServicesService entrance, main disconnect, clearances, number of services
240Overcurrent ProtectionFuses and breakers — sizing, location, accessibility
250Grounding and BondingElectrode system, GEC sizing, EGC, bonding jumpers
300Wiring Methods — GeneralClearances, protection, underground, raceways, fill
310Conductors for General WiringAmpacity, derate rules, insulation types, Table 310.12
312Cabinets, Cutout Boxes, Meter SocketsWire bending space, installation requirements
314Outlet, Junction, Pull BoxesBox fill calculations, covers, accessibility
330–398Wiring Methods (Specific)NM cable (330), MC cable (330), EMT (358), IMC (342), RMC (344), FMC (348), wireways (376)
400Flexible Cords and CablesPermitted uses, prohibited uses, cord types
404SwitchesDisconnecting means, snap switches, ratings
406ReceptaclesRatings, configurations, tamper-resistant, GFCI, AFCI, WR
410Luminaires (Light Fixtures)Installation, clearances, damp/wet locations, recessed fixtures
430MotorsConductor sizing, OCPD, overloads, disconnects, controllers
440HVAC EquipmentAir conditioning and refrigeration equipment — FLA, branch circuits
445GeneratorsLocation, OCPD, grounding, portable vs. permanently installed
450TransformersInstallation, OCPD, clearances, vaults
500–516Hazardous LocationsClass I/II/III, Division 1/2, Zone 0/1/2, approved equipment
517Health Care FacilitiesPatient care areas, essential electrical systems, isolated power
625Electric Vehicle ChargingEV outlet requirements, EVSE, bidirectional charging (new in 2026)
680Swimming Pools and SimilarBonding, GFCI, equipotential bonding grid, lighting clearances
700–702Emergency and Standby SystemsWhen required, wiring methods, transfer equipment, testing
706Energy Storage SystemsBattery systems, solar+storage, disconnecting, ventilation (major NEC 2026 expansion)
800+CommunicationsTelephone, broadband, coax — Chapter 8 stands alone

How to Use the NEC Fast on an Open-Book Exam

  • Buy a spiral-bound copy — it lays flat on the desk while you write.
  • Tab the most-tested articles: 100, 210, 220, 230, 240, 250, 300, 310, 430, 440, 450.
  • Use the index first — look up the keyword, not the article number. Example: "swimming pool bonding" → finds Art. 680 faster than flipping through Chapter 6.
  • Know where these key tables are: 310.12 (conductor ampacity), 250.66 (GEC sizing), 430.250 (3-phase motor FLA), 220.55 (cooking equipment demand).

NEC Code Practice — FAQ

Which NEC edition should I study?

Check your state licensing board website. As of 2026, many states are on NEC 2023. Some are beginning to adopt NEC 2026. Our tests are tagged by NEC edition so you can filter to the right one.

Is the NEC open book on the licensing exam?

For most state electrician licensing exams, yes. You can bring your codebook. But you need to be fast — there is no time to read articles from scratch during the exam. Know which article to go to, then use the book to confirm the exact rule.

What is the hardest part of the NEC to learn?

Most people struggle with Article 220 (load calculations) and Article 430 (motors) because they require multiple steps and correct table lookups. Practice these articles the most. Article 250 (grounding) is also heavily tested and confusing at first — read it slowly and work through examples.

How is Chapter 5 different from the rest of the NEC?

Chapters 5, 6, and 7 cover special situations and they override the general rules in Chapters 1–4. For example, the rules for hazardous locations (Art. 500) override the normal wiring method rules in Chapter 3 for those locations. This "override" structure is an important concept the exam tests.

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