Welcome to necprep

This site is built in the order that matters. Step 1 is the aptitude test you have to pass to start the IEC Southern Indiana–Evansville apprenticeship. Step 2 is the IEC First Year material from your own books, so the first months of class feel familiar instead of brand new.

Aptitude units complete

0 of 6 units

First Year starter units complete

0 of 4 starter units

Basics Lab

Hands-on simulators and games: Ohm’s Law, series vs. parallel, a fraction game, and wire basics.

Wire basics quiz not finished yet

Pick up where you left off

Nothing started yet. The Refresher is the best first move — it warms up the math and reading basics, then hands you the diagnostic to show exactly what to work on.

Aptitude Prep

Straight talk about the real test: IEC Southern Indiana–Evansville officially describes its entrance test only as a basic aptitude test in math and reading. The chapter does not publish the number of questions, a time limit, a passing score, or a calculator rule. Everything on this site is general practice built a little wider and harder than “basic,” so you walk in over-prepared — it is not a copy or a claim about the real test.

Step 1: Start Here — Refresher

Not done

New in v1.1: warm up before you measure. Five short screens — order of operations, fractions & percents, algebra moves, measurement, and how to work a reading passage — with a quick check question after most of them. The checks do not count as a score. At the end, the diagnostic is waiting for you. This is the recommended path, not a lock: the diagnostic and units below are open either way.

Step 2: Take the Diagnostic

Not taken

20 questions, mixed math and reading, no timer. At the end you get a topic-by-topic breakdown of your strong and weak spots, saved on the Progress tab. Take it at the end of the Refresher, while the basics are fresh.

Step 3: Work the Units

Each unit is a short lesson with worked examples, then a quiz. Score 80% or better to mark a unit complete. Misses are tracked on the Progress tab so you can see your most-missed topics.

Practice Test

General practice only — this is not the real IEC test and its format is not published. This set is built harder on purpose: 30 questions drawn from the whole aptitude pool, 40 minutes on the clock, no feedback until the end, just like test day pressure.

Timed Practice Test

When you start, the timer starts. Answer each question to move to the next. Your score and a per-topic breakdown appear at the end, and the attempt is saved to your history.

Basics Lab

Do not just read about electricity — poke it. Every tool here actually works: move the sliders and watch what changes.

🔬 Ohm’s Law Simulator

Ohm’s Law ties three things together: Voltage (V) pushes, Current (I) flows, Resistance (R) pushes back. The rule is V = I × R. Power (watts) is P = V × I.

Voltage: 12 V Resistance: 12 Ω

Current: 1.00 A • Power: 12 W

Watch the bulb: more power means a brighter bulb. Raise the voltage and current climbs. Raise the resistance and current falls.

Practice mode: solve for the missing value

💡 Series vs. Parallel Explorer

Three bulbs, one 12 V battery. Flip between the two ways of wiring them and see why houses are wired in parallel.

Bulb 1 resistance: 6 Ω Bulb 2 resistance: 6 Ω Bulb 3 resistance: 6 Ω

Total resistance: 18 Ω • Total current: 0.67 A

🏃 Fraction Sprint

60 seconds. Fraction and percent questions, generated fresh every round. Beat your best score.

Score: 0 • Time: 60s • Best: 0

Press start and answer as many as you can.

First Year — Your Books, One Track

Your IEC First Year Manual and Workbook are built around Electrical Wiring Residential and the house plans in it, with the 2020 NEC as the rule book. So this is one merged track: for each topic you get the IEC lessons, the matching Residential unit to read, and the NEC article to look up in your own code book.

Everything taught here is written fresh for this site. Lessons follow the same topics and order as your books, but the words, examples, and questions are original — when a lesson gives you an NEC article number, that is your cue to open your own NEC and find it. Learning to find things in the code book is half the trade.

The Full First Year Map

IEC Lessons	Topic	Read in Residential	Look up in NEC 2020
101, 103	Orientation, safety, how the NEC is organized	Unit 1	Art. 90, 100, 110
102	Tools, fasteners, materials	Unit 1	—
104	Electrical terms, charge and current flow, symbols	Unit 2	Art. 100
105–106	Trade math, Ohm’s Law intro, boxes	Units 2–3	Art. 314
107	Conduit bending	—	Ch. 3 raceway articles
108	Dwelling circuits and outlet requirements	Unit 3	Art. 210, 220
109	Conductor types and ampacity, overcurrent protection, NM cable	Unit 4	Art. 240, 310, 334
110	Voltage drop, AC/MC cable, raceway types	Unit 4	Art. 320, 330
111	Checkpoint exam	Review Units 1–4	Review
112	Grounded vs. grounding conductors, switches, receptacles	Unit 5	Art. 200, 404, 406
113	GFCI, AFCI and protective devices	Unit 6	Art. 210
114	Luminaires, ballasts and lamps	Unit 7	Art. 410
115–117	Box fill and series circuits, room by room	Units 8–10	Art. 210, 314
118	Checkpoint exam	Review Units 5–10	Review
119–121	Parallel circuits, laundry, bath and garage circuits	Units 11–16	Art. 210
122–124	Special-purpose outlets, ranges, bath heat/vent	Units 19–22	Art. 422
125–126	Heating and AC circuits, low-voltage and fire alarm	Units 23–26	Art. 424, 440, 725, 760
127	Checkpoint exam	Review	Review
128–129	Multiwire and combination circuits, conduit fill	Unit 4	Art. 310, Ch. 9
130–133	Services, grounding and bonding, service calculations	Units 27–29	Art. 220, 230, 240, 250
134–135	Pools and spas, home automation, standby power, solar	Units 30–33	Art. 680, 702, 690
136	Final exam checkpoint	Full review	Full review

Note: IEC does not publish the exact lesson list for the 2022–2023 edition online. This map follows IEC’s published curriculum objectives for the following year, which uses the same lesson numbers — treat it as a close guide, and check it against the contents pages of your own Manual.

Starter Units — Fully Built

In the Build Queue

These come next, in IEC order. The map above already tells you what to read in your books for each one.

The Next Step — Around the Test

What Evansville IEC publishes as its requirements

From the chapter’s own apprenticeship page, in plain words:

A high school diploma or GED
A valid driver’s license
Reliable transportation
The ability to pass a basic aptitude test in math and reading
A willingness to learn and work hands-on

The program itself is four years: full-time work with a contractor plus classes two evenings a week, and it carries 46 college credit hours.

The enrollment step Evansville actually publishes

That is the whole published process: go to the Apprenticeship Program page at iec-evansville.com, send the “request more information” form, or call the chapter. Evansville does not publish an application-to-test-to-interview sequence of its own.

How IEC programs generally run it — national version

This is IEC National’s general description of how its programs usually work. It is national and generic — Evansville does not publish its own sequence, so treat this as the likely shape, not a promise.

1. Apply — submit an application with your documents, like your diploma or GED and ID.
2. Take the aptitude test — the math and reading test this site prepares you for.
3. Interview — if you pass, a short interview about your motivation and willingness to learn.
4. Trainee card — if your state requires an apprentice license or trainee card, you get it at this stage.
5. Begin — start the apprenticeship: classroom time plus supervised on-the-job work. That is where your First Year books come in.

Your First Year books

IEC Electrical Apprenticeship Curriculum 2022–2023 — First Year Student Manual
IEC Electrical Apprenticeship Curriculum 2022–2023 — First Year Student Workbook
Electrical Wiring Residential, 20th Edition — Simmons & Mullin, based on the 2020 NEC
NFPA 70 — National Electrical Code, 2020

The First Year tab on this site is organized to match these four books.

Tips & Hooks

Memory devices for the stuff that has to stick, study cards built from the questions you miss, and an AI box for anything that's still fuzzy.

🤖 Ask AI Anything

Stuck on a concept — Ohm's Law, a code article, a math move? Ask here. The answer comes back in plain language.

📚 My Questions

Everything you've asked the AI on this site, newest first.

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🃏 Study Cards — Your Most-Missed Questions

Built from your own misses, worst first. Tap a question to open its card.

🧠 Hooks Library

One memory device per big idea. Learn the hook and the answer comes with it.

🖨️ Cheat Sheet — Key Numbers

necprep — Key Numbers

Conversions

12 in = 1 ft	3 ft = 1 yd	36 in = 1 yd
5,280 ft = 1 mi	100 cm = 1 m	1,000 m = 1 km

Formulas

Ohm's Law: V = I × R • I = V ÷ R • R = V ÷ I
Power: P = V × I (the PIE: P = I × E)
Series resistance: R-total = R1 + R2 + R3 (one road — resistances just add)
Parallel resistance: the total is always LESS than the smallest branch (more roads, easier flow)
Area: length × width • Triangle area: ½ × base × height • Volume: length × width × height
Perimeter: add all the sides • Circumference: π × diameter (≈ 3.14 × d)
Percent: part = percent × whole • 10% is the decimal point hopped one place left
Slope: rise ÷ run

🖨️ Cheat Sheet — All Hooks

Glossary

The words and ideas that keep showing up on the test and in the books — in plain language, with a quick example for each. Search a word, or browse by group.

Progress

Practice test attempts

Clear only your saved practice-test attempts. Unit scores, the diagnostic, and everything else stay put.

Start over

Clears every unit score, the diagnostic, practice test history, most-missed topics, and game bests stored on this device.