Master prep
Master course and practice exams
Practice master-level load, service, feeder and motor calculations on the 2023 NEC, then sit a timed 100-question practice exam.
Practice “Electrical theory and calculations” in the courseYou read the free sample for this module. The course has the full lesson and its practice questions, one at a time with the explanation after each answer.
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Answers come from this course's own plans and contents.
- 12 modules of lessons, each with a short check
- 2 timed practice exams
- 158 flashcards with spaced review
Lifetime access, including your retake
Not ready? Try the free 10-question check
Other options
Have my manager pay instead
Everything in Master course
Learn the load calculations, service and feeder sizing and design rules master exams lean on, then prove it on timed 100-question practice exams.
- 12 lesson modules covering every task in PSI's Master Electrician outline
- A week-by-week study plan built from your free check and exam date
- 292 original questions, each explained with the reference it uses
- 2 timed exams (100 questions in 240 minutes, full length at our estimate), weighted like the real exam
- Each practice exam is one 100-question portion on a 240-minute clock, the length and time of Oklahoma's master-level electrical contractor exam. State master exams differ in length, time and passing score, and most add state law and rules; the practice exam does not match any one state's exam.
- After each timed exam, see how each domain moved since your last one
- Domain scores after every drill show what to study next
- Exam-day checklist: what to bring, allowed references and the calculator rules
- Today's 10: ten a day, and every miss comes back until you get it right
- Listen to Today's 10 on the go
- Readiness by domain, from your own practice results
- Every question, reshuffled into new sets aimed at your weakest domain
- Flashcards for every domain, with spaced review
- Lug, your AI study assistant
Best if: You want a clear path through the master-level NEC topics and calculations state master exams test.
What's covered
- Definitions, general requirements and plans (Topic NM.1)
- Electrical theory and calculations (Topic NM.2)
- Branch circuits (Topic NM.3)
- Dwelling load calculations (Topic NM.4)
- Load calculations for other occupancies (Topic NM.5)
- Services and feeders (Topic NM.6)
- Overcurrent protection (Topic NM.7)
- Grounding and bonding (Topic NM.8)
- Conductors, cables, raceways and boxes (Topic NM.9)
- Motors, generators and transformers (Topic NM.10)
- Special occupancies and special equipment (Topic NM.11)
- Utilization equipment, lighting, low voltage and safety (Topic NM.12)
In Master course
- 292original questions
- 2timed practice exams
- 12modules of lessons
- 158flashcards
See how Lug answers
Current from power and voltage
A 1,200 watt heater runs on 120 volts. How much current does it draw?
You: How do I find the current a heater draws when I only know watts and volts?
Lug: Divide watts by volts. A 1,200 watt heater on 120 volts draws 1,200 / 120 = 10 amps.
Key point: For a simple resistive load, amps equal watts divided by volts.
An original example, not an exam question. AI can be wrong, so check it against your course.
What members get
With the course.
Today's 10 10 questions a day from your misses and your weakest domain, so what you got wrong comes back. Plus a missed set of up to 50.
A plan to your exam date Set your date and get a week-by-week plan you can add to your calendar in one tap.
Readiness by domain Your practice results against a 75% study target, and how they moved this week. A study target, not a pass prediction.
- Timed exams on the real clock. A live pace line, and Save and exit when you need a break. You pick up with the time you had left.
- Where your time went. After an open-book timed exam, your slowest questions become a practice set.
- An exam-day guide. What to bring, the references you may use and the calculator rules.
- 292 original questions, every one explained. Review every miss after each timed exam. Practice sets show you the ones you haven't seen first.
- Wrong answer key? We fix it within 2 business days and log it publicly.
- One payment. No subscription, nothing renews.
- Didn't pass? Every plan except the 7-day pass has lifetime access. Your retake prep is already paid for.
Practice drawn to the Master outline: every domain within 1 point of its exam weight
- Definitions, General Requirements, and Plans5%
- Electrical Theory and Calculations8%
- Branch Circuits6%
- Dwelling Load Calculations10%
- Load Calculations for Other Occupancies9%
- Services and Feeders10%
- Overcurrent Protection6%
- Grounding and Bonding10%
- Conductors, Cables, Raceways, and Boxes9%
- Motors, Generators, and Transformers10%
- Special Occupancies and Special Equipment11%
- Utilization Equipment, Lighting, Low Voltage, and Safety6%
See the numbers
Each domain's weight on the Master outline, as our timed exams draw it, beside its share of the 292-question bank.
| Domain | Outline | Bank |
|---|---|---|
| Definitions, General Requirements, and Plans | 5% | 5% |
| Electrical Theory and Calculations | 8% | 8% |
| Branch Circuits | 6% | 6% |
| Dwelling Load Calculations | 10% | 10% |
| Load Calculations for Other Occupancies | 9% | 8% |
| Services and Feeders | 10% | 10% |
| Overcurrent Protection | 6% | 6% |
| Grounding and Bonding | 10% | 10% |
| Conductors, Cables, Raceways, and Boxes | 9% | 9% |
| Motors, Generators, and Transformers | 10% | 10% |
| Special Occupancies and Special Equipment | 11% | 10% |
| Utilization Equipment, Lighting, Low Voltage, and Safety | 6% | 6% |
Instant access. Everything in the plan you choose opens as soon as checkout completes.
See the teaching before you buyRead a complete lesson from the course, “Voltage drop: sizing feeders and branch circuits for it”, and try a short practice set with full explanations. Free, no signup.
Read the free lessonWhat the course covers
12 modules, mapped to the task numbers in Each state's electrical licensing board; exams delivered by PSI, Prov and other vendors's published Master Electrician content outline.
- Definitions, general requirements and plans (Topic NM.1)Finding a definition in Article 100 · General requirements and working space in Article 110 · Reading one-line diagrams and panel schedules
- Electrical theory and calculations (Topic NM.2)Power, power factor and kVA in single- and three-phase systems · Voltage drop and sizing conductors for it · Available fault current basics
- Branch circuits (Topic NM.3)Required branch circuits and receptacle outlets · Branch circuit ratings and continuous loads · Multiwire branch circuits, GFCI and AFCI
- Dwelling load calculations (Topic NM.4)The standard method for a one-family dwelling · The optional method and additions to existing dwellings · Multifamily dwellings · Neutral load for dwellings
- Load calculations for other occupancies (Topic NM.5)Commercial lighting and receptacle loads · Show windows, signs and kitchen equipment · Optional methods for schools and restaurants · Farm loads and demand factors
- Services and feeders (Topic NM.6)Sizing service and feeder conductors from a calculated load · Neutral sizing and parallel conductors · Service and building disconnects · Outside feeders and available fault current
- Overcurrent protection (Topic NM.7)Standard ratings and the next size up · Feeder and transformer taps · Coordination and series ratings
- Grounding and bonding (Topic NM.8)Sizing the grounding electrode conductor · Sizing equipment grounding conductors, including parallel runs · Separately derived systems · Bonding jumpers and multiple buildings
- Conductors, cables, raceways and boxes (Topic NM.9)Ampacity with correction and adjustment · Conduit fill and box fill · Pull boxes and cable tray · Choosing a wiring method
- Motors, generators and transformers (Topic NM.10)Motor full-load current and branch-circuit conductors · Motor overload and short-circuit protection · Multiple-motor feeders · Transformer sizing and protection · Generators
- Special occupancies and special equipment (Topic NM.11)Hazardous locations · Health care and assembly occupancies · Pools, spas and marinas · Emergency and standby systems and fire pumps · Solar PV, EV charging and welders
- Utilization equipment, lighting, low voltage and safety (Topic NM.12)Appliances and HVAC equipment · Luminaires and signs · Class 2 and fire alarm circuits · NFPA 70E and OSHA basics
Questions
When do I get access?
Straight away. Checkout takes you to your course, and the receipt email has the same link.
How do I get back into my course?
Use the link in your receipt email. If you can't find it, enter your email on the course page and we resend it to the address on your order.
Is 292 questions enough?
Each one comes with a worked explanation and its reference. You also get 36 end-of-module checks. Today's 10 and your missed set bring your misses back on later days, so you work the bank instead of reading it once.
Can I get a refund?
Eligibility depends on your plan, when you request a refund and your paid use. See the refund terms for the conditions and exceptions.
What if I need a retest?
Keep studying in the same course. Your access has no end date, so your retake prep is already paid for, and your practice history, missed questions and readiness by domain are still there. The 7-day pass is the exception: it ends after 7 days.
How long do I keep access?
Lifetime access: your access has no end date. Updates are included, so if Each state's electrical licensing board; exams delivered by PSI, Prov and other vendors moves this exam to a newer code edition while you have access, your course moves with it. The 7-day pass is the exception. 7-day pass: access ends 7 days after payment, to the minute. It does not renew and is not a subscription. A timed practice exam started before then can still be finished.
More questions (6)
If I buy the 7-day pass now, is its price taken off a bigger plan later?
No. Each plan is a separate purchase at its listed price, and the $29 paid for the 7-day pass is not credited toward another plan. With more than a week before your exam, a full plan is the better buy.
Are the questions copied from the exam?
No. Every question is original and written to Each state's electrical licensing board; exams delivered by PSI, Prov and other vendors's published content outline. Exam content is confidential and we never use it. We are not affiliated with or endorsed by TDLR, PSI, Prov or NFPA.
How are the questions written?
In our own words, to PSI's current published outline. See how many questions cover each domain.
Can my employer pay?
Yes. Pay at checkout and we email a receipt you can expense, or download a reimbursement request to send your manager.
Is Lug AI?
Yes. Lug is an AI study assistant, not a person or an instructor. Check important details against your lessons and references.
Can you promise I will pass?
No, and nobody honest can. We promise everything listed in your plan, and a fix within 2 business days for any wrong answer key.
Employer paying?
Many employers fund Master prep. Generate a reimbursement request PDF to send to your manager. Buying for a crew? Request a quote