- What the 12-Area Outline Actually Is
- Question Allocation at a Glance
- The Calculation Domains: 2 and 3
- Equipment and Enclosure Domains: 1, 8 and 11
- Conductors, Protection and Wiring Methods: 4 and 12
- Utilization Domains: 5, 6 and 7
- Special Installations and Special Occupancies: 9 and 10
- Choosing the Code Edition and Preparing References
- Sequencing the Domains in Your Prep
- Exam Mechanics That Shape How You Study
- Frequently Asked Questions
- The Electrical General (2B) exam has 12 official subject areas covering 50 questions in two hours.
- Special Installations or Constructions carries the most questions: eight of the 50.
- The bulletin publishes item counts, not percentage weights, so study to counts rather than invented percentages.
- The exam is open book, so code navigation speed matters as much as memorization.
What the 12-Area Outline Actually Is
The Electrical General (2B) examination is a computer-based, four-option multiple-choice test that is part of the NCPCCI program (National Certification Program for Construction Code Inspectors). It has 50 questions, a two-hour time limit, and an official cut-score of 70. It is open book, which changes how every domain should be studied. The exam is currently administered by Prov, with testing at its centers or through ExamRoom.AI remote proctoring.
The outline below comes from page 5 of the Prov NCPCCI Candidate Information Bulletin (printed version 2024.03.12). These are the official exam subject areas, not a preparation curriculum. That distinction matters: the bulletin tells you what can be tested, not how to learn it. For the broader preparation strategy, see our 2B study guide.
If you are still orienting yourself to the credential itself, our explainers on what 2B is and what 2B certification is cover the basics. This article focuses on the content areas.
Question Allocation at a Glance
The official allocations, in Domain 1 through 12 order, are 4, 3, 3, 4, 1, 4, 5, 5, 8, 5, 3 and 5. They total 50.
| Domain | Subject Area | Official Question Count |
|---|---|---|
| 1 | Cabinets, Panelboards, Switchboards, Boxes, and Conduit Bodies | 4 |
| 2 | Calculations of Load | 3 |
| 3 | Calculations of Wire Size | 3 |
| 4 | Conductors and Overcurrent Protection on the Load Side of the Service | 4 |
| 5 | Generators other than Dwellings | 1 |
| 6 | Lighting and Utilization Equipment | 4 |
| 7 | Motors other than Dwellings | 5 |
| 8 | Service Equipment and Conductors on the Supply Side of the Service | 5 |
| 9 | Special Installations or Constructions | 8 |
| 10 | Special Occupancies | 5 |
| 11 | Switches, Disconnects and Controllers | 3 |
| 12 | Wiring Methods | 5 |
Two patterns stand out. First, Special Installations or Constructions is the single largest allocation at eight questions. Second, no single domain dominates: the next-largest areas (Motors, Service Equipment, Special Occupancies, and Wiring Methods) each carry five. A candidate who skips any one mid-sized domain gives up roughly a tenth of the exam.
The Calculation Domains: 2 and 3
Domains 2 (Calculations of Load) and 3 (Calculations of Wire Size) account for six questions combined. They are small in count but large in time cost, because calculation items take longer than lookup items. The on-screen calculator provides basic arithmetic and square root only, so you should be comfortable doing multi-step work without advanced functions.
Domain 2: Calculations of Load (3 questions)
Expect scenario-based items where you assemble a load from the code's calculation rules and arrive at a number.
- Know where the code's load calculation rules are located so you can open directly to them.
- Practice applying demand factors in the correct order rather than memorizing outcomes.
- Watch for items that mix continuous and noncontinuous loads.
Domain 3: Calculations of Wire Size (3 questions)
These items ask you to select or verify a conductor size from stated conditions.
- Practice with the ampacity tables and their correction and adjustment provisions.
- Learn the order of operations: which adjustment applies first, and which limit ultimately governs.
- Confirm termination-temperature limitations, since they frequently decide the final answer.
Calculation questions are where edition mismatches hurt most, because table values and rule numbering are specific to the code edition. More on that below. For a sense of how these domains affect overall difficulty, read how hard the 2B exam is.
Equipment and Enclosure Domains: 1, 8 and 11
Domains 1, 8 and 11 together carry twelve questions (4, 5 and 3). They share a theme: the hardware that distributes, protects and controls power.
Domain 1: Cabinets, Panelboards, Switchboards, Boxes, and Conduit Bodies (4 questions)
Items test installation, construction and capacity rules for the enclosures and distribution equipment.
- Box fill and conduit body sizing are classic lookup-and-calculate topics.
- Panelboard and switchboard rules include overcurrent protection arrangements, spacing and working-space-related requirements.
- Know the difference between rules for enclosures in damp or wet locations and those in dry locations.
Domain 8: Service Equipment and Conductors on the Supply Side of the Service (5 questions)
This domain concerns equipment and conductors ahead of the point where load-side rules begin.
- Understand service conductors, service disconnecting means and grounding and bonding at the service.
- Keep the boundary clear between supply-side and load-side rules; confusing them is a common error.
- Pay particular attention to service equipment requirements where overcurrent protection and disconnect rules intersect.
Domain 11: Switches, Disconnects and Controllers (3 questions)
Items cover where and how switching and disconnecting means are required, rated and located.
- Know the ratings and use limits for different switch types.
- Be able to find disconnect requirements for specific equipment categories quickly.
These three domains reward familiarity with the code's article structure. Because the exam is open book, a candidate who knows which article governs a topic can locate the answer faster than one relying on recall.
Conductors, Protection and Wiring Methods: 4 and 12
Domain 4: Conductors and Overcurrent Protection on the Load Side of the Service (4 questions)
This is the load-side counterpart to Domain 8, covering how branch circuits and feeders are conductor-sized and protected.
- Study the relationships among conductor ampacity, overcurrent device rating, and the rules that permit rounding up to the next standard size.
- Know the exceptions that allow deviations, as exam items often hinge on them.
- Understand tap rules and their length and ampacity limits.
Domain 12: Wiring Methods (5 questions)
Items test which wiring methods are permitted, restricted or required in given conditions, along with installation requirements.
- Learn the permitted-uses and not-permitted-uses sections for the common raceway and cable types.
- Practice support, securing and bending-related requirements.
- Expect questions that ask you to choose a method appropriate to an environment or building type.
Domains 3, 4 and 12 interact: choosing a wiring method affects conductor ampacity, which affects overcurrent protection. Studying them as a connected chain rather than isolated topics is more effective than treating each in a vacuum.
Utilization Domains: 5, 6 and 7
Domain 5: Generators other than Dwellings (1 question)
The smallest allocation on the exam. Expect at most a single item on generator installation and related requirements for non-dwelling applications.
- Because it is one question, treat it as a lookup skill: know where generator rules sit in your reference.
- Do not let it consume prep time that belongs to larger domains.
Domain 6: Lighting and Utilization Equipment (4 questions)
This covers luminaires, lampholders and other equipment that consumes power.
- Know luminaire installation rules by location type.
- Understand clearance and support requirements for fixtures and associated equipment.
Domain 7: Motors other than Dwellings (5 questions)
Motor items are among the most calculation-heavy topics in the exam, tying together conductor sizing, overcurrent protection and disconnecting means.
- Learn how motor conductor and protection sizing differs from general circuit rules.
- Use the motor full-load current tables as the code directs, not the nameplate, where the rules call for it.
- Practice items that combine a motor with its controller, overload protection and disconnect.
Motors reward practice more than any other utilization domain. At five questions, they are worth building a dedicated set of worked problems.
Special Installations and Special Occupancies: 9 and 10
Domain 9: Special Installations or Constructions (8 questions)
This domain draws on the code's specialized articles that modify or supplement the general rules for particular installation types.
- Because the topic range is wide, focus on how special-condition articles modify general rules rather than memorizing each in isolation.
- Practice finding the governing article for an unfamiliar scenario using the index and table of contents.
- Expect scenario items where you must identify which special rule overrides the general one.
Domain 10: Special Occupancies (5 questions)
Items address occupancy types with elevated hazard or use-specific wiring requirements.
- Understand how occupancy classification changes the permitted wiring methods and equipment.
- Be ready for questions where the answer depends on recognizing the occupancy type first.
These two domains are where open-book candidates most often lose time. Tabbing the special-articles section of your reference in advance, within the reference rules in the bulletin, pays off here.
Choosing the Code Edition and Preparing References
The bulletin lists the NEC 2017 and NEC 2020 forms of the exam, with identical subject allocations. The 2020 form is the newer listed form, titled 2B Electrical General (2020 Code), using NFPA 70, National Electrical Code, 2020 edition. Other editions of the same reference title may be brought, but the specified edition governs answers. That means a candidate carrying a different edition still gets graded against the specified one.
Key Takeaway
Decide which exam form you are booking before you buy references. A study guide based on the NEC 2023 is preparation material, not evidence of a newer NCPCCI 2B exam form, so verify the form against the bulletin rather than the book's cover.
Reference rules matter. Applicable approved references may be highlighted and permanently tabbed before testing, and the NEC Handbook is permitted where applicable. The reference-rules appendix (PDF page 22 of the bulletin) is the authority; read it before exam day and confirm current rules with Prov, particularly if you plan to test via remote proctoring.
Sequencing the Domains in Your Prep
Generic study methods are less useful than a domain order that follows how the topics build on each other. One reasonable sequence uses the logical flow of an electrical system:
Orient and tab the reference
- Skim the full code structure and tab the major articles.
- Cover Domain 12 (Wiring Methods) and Domain 1 (enclosures) as foundation vocabulary.
Supply side to load side
- Study Domain 8 (supply side), then Domain 4 (load side).
- Add Domain 11 (switches and disconnects).
Calculations
- Work Domains 2 and 3 with timed problems.
- Add Domain 7 (motors), since it reuses the same sizing logic.
Special rules and review
- Spend the largest block on Domain 9 and Domain 10.
- Fold in Domains 5 and 6, then run full 50-question timed sets.
This ordering puts the 8-question domain late, when you already understand the general rules it modifies. Adjust the pacing to your own experience; our full 2B study guide and 2B cheat sheet offer further planning support, and you can test your recall with the 2B practice tests.
Exam Mechanics That Shape How You Study
The format interacts with the domains in ways that affect strategy:
- Time: 50 questions in two hours leaves about two and a half minutes per question on average. Calculation items will run longer, so lookup items must go faster.
- Cut-score: The official cut-score is 70. This is a scoring threshold, not an empirical pass rate; no authoritative current pass rate has been verified for this exam. See our discussion of the 2B pass rate and the 2B passing score.
- Fee and retakes: The exam fee is USD 130 per attempt, including retakes, and a failed attempt requires a 30-day wait before retaking. Details are in our 2B certification cost breakdown.
- Eligibility: NCPCCI imposes no prequalifications to sit the exam. Passing alone does not confer a local license or certification. See 2B requirements for how this fits with licensing.
For scheduling, testing windows and remote-versus-center options, see 2B exam dates. For the career side, our pieces on 2B jobs, 2B salary and whether 2B certification is worth it cover the payoff question, and the domain guide you are reading now is the reference for the content itself.
Frequently Asked Questions
The Electrical General (2B) exam has 12 official subject areas, with question allocations of 4, 3, 3, 4, 1, 4, 5, 5, 8, 5, 3 and 5 in Domain 1 through 12 order, totaling 50 questions.
Special Installations or Constructions (Domain 9) has the largest allocation at eight questions. Generators other than Dwellings (Domain 5) has the smallest at one.
No. The bulletin publishes item counts only. Any percentage figure you see for these domains is not an official weight and should be treated as a third-party estimate.
Yes. Applicable approved references may be highlighted and permanently tabbed before testing, and the NEC Handbook is permitted where applicable. The on-screen calculator provides basic arithmetic and square root only.
The bulletin lists NEC 2017 and NEC 2020 forms with identical subject allocations, and the 2020 form is the newer one. Other editions may be brought, but the specified edition governs answers, so match your prep to the form you book.