PE Electrical and Computer Power Exam Prep
Free PE Power exam prep built on the NCEES specification that took effect in October 2025: 28 original practice questions with worked solutions, then a 12-week study plan. Work Question 1 now, and keep a note of which ones you miss.
PE Power practice: 28 original questions with worked solutions
Original, unofficial practice written by Castleport Test Prep. These are not NCEES exam questions. There are 3 questions for each of the nine knowledge areas, plus 1 on exam setup.
Question 1 · Circuit Analysis · Three-phase circuits
ID PWR-CA-01
A balanced three-phase load draws 100 kW at 0.80 power factor lagging from a 480 V (line-to-line) supply. What is the line current, in amperes?
Enter a number.
Reveal answer
Answer: 150 A (150.4 A) (accepted: ±1 A)
I = P ÷ (√3 × V(LL) × pf) = 100,000 ÷ (1.732 × 480 × 0.80) = 150.4 A.
Common wrong answers:
- 260 A: the √3 was dropped (100,000 ÷ (480 × 0.80)).
- 120 A: power factor was ignored, so kW was treated as kVA.
- 86.8 A: √3 was applied twice.
Basis: Derived from P = √3·V(LL)·I·pf; inputs given in the stem.
Missed it? Study Circuit Analysis in Weeks 1–2 of the plan.
Answer checking and Reset use JavaScript. Without it, record your responses and compare them with the native answer reveals or Show all answers.
Numeric tolerance checks use the precise parenthetical answer where one is supplied.
Question 2 · Transmission and Distribution Analysis · Power factor correction
ID PWR-TD-01
A plant draws 500 kW at 0.75 power factor lagging. How many kvar of capacitors raise the power factor to 0.95 lagging?
Enter a number.
Reveal answer
Answer: About 277 kvar (276.6 kvar) (accepted: ±3 kvar)
Real power stays at 500 kW. Before: Q = 500 × tan(cos⁻¹ 0.75) = 441.0 kvar. After: Q = 500 × tan(cos⁻¹ 0.95) = 164.3 kvar. Capacitors supply the difference: 441.0 − 164.3 = 276.6 kvar.
Common wrong answers:
- About 140: that's the drop in kVA (667 − 526), not the reactive power the capacitors must supply.
Basis: Derived from the power triangle; inputs given in the stem.
Missed it? Study Transmission and Distribution Analysis in Weeks 5–6 of the plan.
Question 3 · Protection · Protective relaying settings
ID PWR-PR-01
A phase overcurrent relay is fed from 400:5 CTs. It must pick up at 480 A primary. What secondary pickup current is set on the relay?
Enter a number.
Reveal answer
Answer: 6.0 A (accepted: exact)
CT ratio = 400 ÷ 5 = 80. Secondary pickup = 480 ÷ 80 = 6.0 A.
Common wrong answers:
- 38,400 A: the primary current was multiplied by the ratio instead of divided.
Basis: Derived from CT ratio; inputs given in the stem.
Missed it? Study Protection in Week 7 of the plan.
Question 4 · Electrical Safety · Hazardous locations
ID PWR-ES-01
You must classify an area of a chemical process unit that handles flammable vapors. Which standard supplied on the PE Power exam is the recommended practice for that classification?
Reveal answer
Answer: A. NFPA 497
NFPA 497 is the recommended practice for classifying locations with flammable liquids, gases, or vapors in chemical process areas.
Why not the others:
- B: NFPA 499 covers combustible dusts, not vapors.
- C: NFPA 30B covers the manufacture and storage of aerosol products.
- D: NFPA 70E covers electrical safety practices for workers, not area classification.
Basis: Standard titles: NCEES Power specification, design standards table (source)
Missed it? Study Electrical Safety in Weeks 4 and 8 of the plan.
Question 5 · Electric Power Devices · Transformers
ID PWR-PD-01
What is the full-load secondary current of a 1,500 kVA three-phase transformer rated 13.8 kV–480Y/277 V?
Enter a number.
Reveal answer
Answer: 1,804 A (accepted: ±5 A)
I = S ÷ (√3 × V(LL)) = 1,500,000 ÷ (1.732 × 480) = 1,804 A. (On the 13.8 kV side the same formula gives 62.8 A.)
Common wrong answers:
- 3,125 A: the √3 was dropped.
- 5,415 A: kVA was divided by 277 V, as if one phase carried the whole load.
Basis: Derived; inputs given in the stem.
Missed it? Study Electric Power Devices in Week 3 of the plan.
Question 6 · Rotating Machines · Machine types and applications
ID PWR-RM-01
A 4-pole, 60 Hz induction motor runs at 1,764 rpm. What is its slip?
Reveal answer
Answer: B. 2.0%
Synchronous speed = 120 × f ÷ P = 120 × 60 ÷ 4 = 1,800 rpm. Slip = (1,800 − 1,764) ÷ 1,800 = 0.02 = 2.0%.
Why not the others:
- A: Divides the 36 rpm difference by 3,600 rpm instead of the 1,800 rpm synchronous speed.
- C: Treats the 36 rpm difference as a percentage of 1,000.
- D: Doubles the correct slip.
Basis: Derived from n(s) = 120f/P; inputs given in the stem.
Missed it? Study Rotating Machines in Week 10 of the plan.
Question 7 · Power Electronic Circuits and Control Devices · Power electronics: converters
ID PWR-PE-01
What is the ideal average DC output voltage of a three-phase, six-pulse, full-wave diode rectifier fed from 480 V line-to-line?
Enter a number.
Reveal answer
Answer: About 648 V (accepted: ±2 V)
V(dc) = (3√2 ÷ π) × V(LL) ≈ 1.35 × 480 = 648 V.
Common wrong answers:
- 432 V: the single-phase full-wave factor (0.9) was used.
- 679 V: that's the peak line-to-line voltage, not the average.
Basis: Derived from the ideal six-pulse rectifier average; inputs given in the stem.
Missed it? Study Power Electronic Circuits and Control Devices in Week 10 of the plan.
Question 8 · Measurement and Instrumentation · Instrument transformers
ID PWR-MI-01
A relay connected to a 600:5 CT reads 3.75 A. Neglecting CT error, what is the primary current?
Enter a number.
Reveal answer
Answer: 450 A (accepted: ±1 A)
CT ratio = 600 ÷ 5 = 120. Primary current = 3.75 × 120 = 450 A.
Common wrong answers:
- 0.031 A: the ratio was applied upside down.
Basis: Derived from CT ratio; inputs given in the stem.
Missed it? Study Measurement and Instrumentation in Week 9 of the plan.
Question 9 · General Applications · Energy management and demand
ID PWR-GA-01
A facility uses 151,200 kWh in a 30-day month. Its peak demand is 350 kW. What is the load factor?
Enter a number.
Reveal answer
Answer: 0.60 (accepted: ±0.01)
Average demand = 151,200 kWh ÷ 720 h = 210 kW. Load factor = average ÷ peak = 210 ÷ 350 = 0.60.
Common wrong answers:
- Demand factor is a different ratio: maximum demand ÷ connected load.
Basis: Derived; inputs given in the stem.
Missed it? Study General Applications in Week 9 of the plan.
Question 10 · Circuit Analysis · Per-unit system
ID PWR-CA-02
A 20 MVA, 13.8 kV generator has subtransient reactance X″ = 0.15 pu on its own rating. What is X″ on a 100 MVA, 13.8 kV system base?
Reveal answer
Answer: C. 0.75 pu
Z(new) = Z(old) × (S new ÷ S old) × (V old ÷ V new)² = 0.15 × (100 ÷ 20) × 1² = 0.75 pu.
Why not the others:
- A: Inverts the MVA ratio (20 ÷ 100).
- B: Forgets to change base.
- D: Squares the MVA ratio; only the voltage ratio is squared.
Basis: Derived from the per-unit change-of-base relation; inputs given in the stem.
Missed it? Study Circuit Analysis in Weeks 1–2 of the plan.
Question 11 · Transmission and Distribution Analysis · Fault current analysis
ID PWR-TD-02
A 1,500 kVA, 13.8 kV–480Y/277 V transformer has 5.75% impedance. Assuming an infinite source, the three-phase bolted fault current at the secondary terminals is closest to:
Reveal answer
Answer: C. 31,400 A
Full-load current = 1,500,000 ÷ (√3 × 480) = 1,804 A. With an infinite source, fault current = I(FL) ÷ Z(pu) = 1,804 ÷ 0.0575 = 31,378 A, or about 31,400 A.
Why not the others:
- A: That's full-load current, not fault current.
- B: Divides by √3 a second time.
- D: Multiplies by √3 instead of dividing.
Basis: Derived; inputs given in the stem.
Missed it? Study Transmission and Distribution Analysis in Weeks 5–6 of the plan.
Question 12 · Protection · Coordination
ID PWR-PR-02
At the maximum through-fault current, a downstream feeder relay operates in 0.30 s. Using a coordination time interval (CTI) of 0.30 s, the upstream main relay should operate at that same current no faster than:
Reveal answer
Answer: C. 0.60 s
Upstream time ≥ downstream time + CTI = 0.30 + 0.30 = 0.60 s, checked at the same fault current. The CTI value is a design choice for the devices involved; here it's given.
Why not the others:
- A: No margin; the two relays would race.
- B: Uses half the stated CTI.
- D: Adds the CTI twice.
Basis: Derived; CTI given in the stem.
Missed it? Study Protection in Week 7 of the plan.
Question 13 · Electrical Safety · Shock and burns
ID PWR-ES-02
Under NFPA 70E-2021, the arc flash boundary is the distance from a prospective arc source at which the incident energy equals:
Reveal answer
Answer: B. 1.2 cal/cm²
NFPA 70E defines the arc flash boundary by an incident energy of 1.2 cal/cm². Find it in Article 100 (Definitions) of the supplied 2021 edition.
Why not the others:
- A: Not the threshold in the definition.
- C: A common minimum arc rating for some protective clothing, not the boundary definition.
- D: Also a common arc rating, not the boundary definition.
Basis: NFPA 70E-2021, Article 100, definition of “Arc Flash Boundary.” NFPA technical-committee material quotes the definition as the approach limit where incident energy equals 1.2 cal/cm² (NFPA source).
Missed it? Study Electrical Safety in Weeks 4 and 8 of the plan.
Question 14 · Electric Power Devices · Capacitors
ID PWR-PD-02
A capacitor bank rated 50 kvar at 480 V is operated at 460 V. Its reactive output is closest to:
Reveal answer
Answer: A. 45.9 kvar
Capacitor kvar varies with voltage squared: 50 × (460 ÷ 480)² = 45.9 kvar.
Why not the others:
- B: Scales linearly with voltage.
- C: Ignores the voltage change.
- D: Inverts the voltage ratio.
Basis: Derived from Q = V²/X(C); inputs given in the stem.
Missed it? Study Electric Power Devices in Week 3 of the plan.
Question 15 · Rotating Machines · Motor starting
ID PWR-RM-02
Compared with across-the-line starting, an autotransformer starter on its 65% tap reduces the line starting current and the starting torque to approximately what fraction of their full-voltage values?
Reveal answer
Answer: B. 42% and 42%
Motor voltage is 65% of full, so motor current is about 65% of locked-rotor current. The autotransformer steps that current down again by 0.65 on the line side: 0.65 × 0.65 ≈ 42%. Torque varies with voltage squared: 0.65² ≈ 42%.
Why not the others:
- A: Treats torque as proportional to voltage.
- C: Line current at 65% with torque at 42% describes a series resistor or reactor starter, where line current equals motor current.
- D: Reverses the current and torque relationships.
Basis: Derived from torque ∝ V² and the autotransformer current ratio.
Missed it? Study Rotating Machines in Week 10 of the plan.
Question 16 · Power Electronic Circuits and Control Devices · Variable frequency drives
ID PWR-PE-02
A 460 V, 60 Hz motor runs on a VFD with constant volts-per-hertz control. At 45 Hz, what is the drive's output voltage?
Enter a number.
Reveal answer
Answer: 345 V (accepted: exact)
Constant V/Hz keeps flux roughly constant: 460 × (45 ÷ 60) = 345 V.
Common wrong answers:
- 460 V: holding full voltage at reduced frequency would over-flux the motor.
Basis: Derived from constant V/Hz control; inputs given in the stem.
Missed it? Study Power Electronic Circuits and Control Devices in Week 10 of the plan.
Question 17 · Measurement and Instrumentation · Insulation testing
ID PWR-MI-02
A motor stator measures 400 MΩ at 1 minute and 1,000 MΩ at 10 minutes during a polarization-index test. What is the polarization index (PI)?
Reveal answer
Answer: C. 2.50
PI is the 10-minute insulation-resistance reading divided by the 1-minute reading: 1,000 ÷ 400 = 2.50. PI is a ratio, so it has no units.
Why not the others:
- A: Inverts the ratio.
- B: Does not follow from the two readings.
- D: Subtracts the readings and incorrectly gives PI resistance units.
Basis: Megger’s insulation-testing guidance defines PI as the 10-minute insulation-resistance reading divided by the 1-minute reading (source).
Missed it? Study Measurement and Instrumentation in Week 9 of the plan.
Question 18 · General Applications · Illumination/lighting
ID PWR-GA-02
A 40 ft × 50 ft room needs 50 footcandles maintained. Each luminaire produces 5,000 lumens. The coefficient of utilization (CU) is 0.60 and the light loss factor (LLF) is 0.80. Using the lumen method, what is the minimum number of luminaires?
Reveal answer
Answer: D. 42
N = (E × A) ÷ (lumens × CU × LLF) = (50 × 2,000) ÷ (5,000 × 0.60 × 0.80) = 41.7. Round up to 42 so the target is met.
Why not the others:
- A: Leaves out CU.
- B: Leaves out LLF.
- C: Rounds down, so the room falls short of 50 fc.
Basis: Derived from the lumen method; inputs given in the stem.
Missed it? Study General Applications in Week 9 of the plan.
Question 19 · Circuit Analysis · Symmetrical components
ID PWR-CA-03
Phase currents are Ia = 100∠0° A, Ib = 0, Ic = 0. What are the zero-, positive-, and negative-sequence components of phase a?
Reveal answer
Answer: A. I0 = I1 = I2 = 33.3∠0° A
I0 = (Ia + Ib + Ic) ÷ 3 = 33.3 A. I1 = (Ia + a·Ib + a²·Ic) ÷ 3 = 33.3 A. I2 = (Ia + a²·Ib + a·Ic) ÷ 3 = 33.3 A, all at 0°. Equal sequence currents are the signature of a single-line-to-ground fault on phase a.
Why not the others:
- B: Describes a balanced positive-sequence set.
- C: Would need equal, in-phase current in all three phases.
- D: The phase currents don't sum to zero, so the zero-sequence component can't be zero.
Basis: Derived from the symmetrical-component transformation.
Missed it? Study Circuit Analysis in Weeks 1–2 of the plan.
Question 20 · Transmission and Distribution Analysis · Voltage drop
ID PWR-TD-03
A 480 V three-phase feeder carries 200 A at 0.85 power factor lagging over a one-way length of 300 ft. Conductor R = 0.050 Ω per 1,000 ft and X = 0.040 Ω per 1,000 ft. What is the approximate voltage drop as a percent of 480 V?
Enter a number.
Reveal answer
Answer: About 1.38% (accepted: ±0.1 percentage point)
VD ≈ √3 × I × (R cos θ + X sin θ) × L. sin θ = 0.527. VD = 1.732 × 200 × (0.050 × 0.85 + 0.040 × 0.527) × 0.300 = 6.61 V. 6.61 ÷ 480 = 1.38%.
Common wrong answers:
- 1.59%: the single-phase factor 2 was used instead of √3.
- 0.92%: reactance was ignored.
- 2.75%: the one-way length was doubled, which applies only to the single-phase factor-of-2 form.
Basis: Derived from the approximate voltage-drop formula; R and X given in the stem.
Missed it? Study Transmission and Distribution Analysis in Weeks 5–6 of the plan.
Question 21 · Protection · Protective relaying
ID PWR-PR-03
Which device function number designates the differential relay used as primary protection for a large power transformer?
Reveal answer
Answer: C. 87
Device 87 is differential protection, which compares current entering and leaving the protected zone.
Why not the others:
- A: 21 is distance protection, mainly for lines.
- B: 51 is AC time overcurrent, often transformer backup.
- D: 79 is reclosing.
Basis: IEEE Std C37.2 device-function numbering; GE Vernova’s relay documentation identifies 87 as differential, 51 as time overcurrent, 79 as autoreclose, and 21 as distance-related protection (source).
Missed it? Study Protection in Week 7 of the plan.
Question 22 · Electrical Safety · Code scope: NEC vs. NESC
ID PWR-ES-03
Clearance requirements for a utility-owned 12.47 kV overhead distribution line along a public road are found in:
Reveal answer
Answer: C. ANSI C2 (NESC)
The NEC excludes installations under the exclusive control of an electric utility (NEC 2020, 90.2(B)(5)). The NESC covers utility supply and communication lines (NESC 2017, Rule 011).
Why not the others:
- A: Utility-controlled lines are outside NEC scope.
- B: 70E covers safe work practices, not line clearances.
- D: 497 is hazardous area classification.
Basis: NFPA 70-2020, 90.2(B)(5), excludes qualifying installations under the exclusive control of an electric utility; ANSI C2-2017 is the NESC supplied for utility supply/communication-line questions. NFPA code-development material quotes the utility exclusion (source).
Missed it? Study Electrical Safety in Weeks 4 and 8 of the plan.
Question 23 · Electric Power Devices · Electrical energy storage
ID PWR-PD-03
A 200 kWh battery system may use 80% of its nameplate energy. Inverter efficiency is 95%. How many hours can it serve a constant 40 kW AC load?
Enter a number.
Reveal answer
Answer: 3.8 h (accepted: ±0.1 h)
Usable AC energy = 200 × 0.80 × 0.95 = 152 kWh. Time = 152 ÷ 40 = 3.8 h.
Common wrong answers:
- 4.0 h: inverter losses were ignored.
- 5.0 h: both limits were ignored.
Basis: Derived; inputs given in the stem.
Missed it? Study Electric Power Devices in Week 10 of the plan.
Question 24 · Rotating Machines · Motor branch-circuit conductors (NEC 2020)
ID PWR-RM-03
For a continuous-duty three-phase motor, the applicable NEC table full-load current is 65 A. Under NEC 2020 Section 430.22, what is the minimum branch-circuit conductor ampacity?
Enter a number.
Reveal answer
Answer: 81.25 A (accepted: ±0.5 A)
For a single continuous-duty motor, Section 430.22 requires conductor ampacity of at least 125% of the motor full-load current determined under 430.6(A)(1). Here: 1.25 × 65 = 81.25 A.
Common wrong answers:
- 65 A: the 125% factor was skipped.
- 52 A: the 125% factor was inverted.
Basis: NFPA 70-2020, 430.22 and 430.6(A)(1). NFPA’s public code-development material reproduces the 430.22 requirement that conductors for a single continuous-duty motor have ampacity of at least 125% of motor full-load current (source).
Missed it? Study Rotating Machines in Week 10 of the plan.
Question 25 · Power Electronic Circuits and Control Devices · Relays, switches, and ladder logic
ID PWR-PE-03
In a three-wire motor control rung, a normally open START pushbutton is in series with a normally closed STOP pushbutton and coil M. What keeps M energized after START is released?
Reveal answer
Answer: B. A normally open M auxiliary contact in parallel with START
The seal-in (holding) contact closes when M energizes and bypasses START. STOP stays in series so pressing it still breaks the circuit.
Why not the others:
- A: Would open as soon as M energized and drop the coil.
- C: Would bypass STOP, so the motor couldn't be stopped.
- D: Adds delay, not a holding path.
Basis: Standard three-wire start/stop control logic.
Missed it? Study Power Electronic Circuits and Control Devices in Week 10 of the plan.
Question 26 · Measurement and Instrumentation · Ground resistance testing
ID PWR-MI-03
You run a fall-of-potential test on a single driven rod in uniform soil. The current probe is 100 m from the rod. Where should the potential probe go?
Reveal answer
Answer: A. About 62 m from the rod
For a small electrode in uniform soil, the reading at about 61.8% of the distance from the electrode under test to the current probe matches the electrode's true resistance (the 62% rule in IEEE 81).
Why not the others:
- B: Midpoint has no special meaning here.
- C: Measures 62% from the current probe, the wrong end.
- D: At the current probe the reading is dominated by that probe's own resistance.
Basis: IEEE Std 81-2012, Annex C, as explained at source
Missed it? Study Measurement and Instrumentation in Week 9 of the plan.
Question 27 · General Applications · Grounding (NEC 2020)
ID PWR-GA-03
At a 480Y/277 V service, which connection joins the equipment grounding conductors and the service enclosure to the grounded (neutral) service conductor?
Reveal answer
Answer: B. Main bonding jumper
The main bonding jumper connects the equipment grounding conductors and service enclosure to the grounded conductor at the service. That completes the path that lets fault current trip the overcurrent device (NEC 2020, 250.24(B) and 250.28).
Why not the others:
- A: Connects to the grounding electrode, not to the EGC system.
- C: Bonds metal parts on the supply side; it isn't the neutral-to-EGC connection.
- D: Load-side bonding doesn't connect to the neutral.
Basis: NFPA 70-2020, 250.24 and 250.28. NFPA code-development material states that the main bonding jumper connects the equipment grounding conductor(s) and service-disconnect enclosure to the grounded conductor (source).
Missed it? Study General Applications in Week 9 of the plan.
Question 28 · Exam setup · Supplied references
ID PWR-EX-01
Which of these are supplied design standards on the PE Power exam under the October 2025 specification? Select all that apply.
Reveal answer
Answer: A (NFPA 70-2020 (NEC)), B (NFPA 70E-2021), C (ANSI C2-2017 (NESC))
All-or-nothing: credit only when exactly A, B, and C are selected.
The specification lists NFPA 30B-2023, NFPA 70-2020, NFPA 70E-2021, NFPA 497-2021, NFPA 499-2021, and ANSI C2-2017. Answers that depend on a standard are scored on the listed edition.
Why not the others:
- D: The 2023 NEC isn't the edition on the current list.
- E: IEEE 242 isn't a supplied standard.
Basis: NCEES Power specification, design standards table and notes (source)
Missed it? Study Exam setup in Week 1 of the plan.
Reading your results
Count your correct answers in each knowledge area. Any area where you got 0 or 1 of 3 right is where to start: each explanation names the plan week that covers it.
Three questions per area is a small sample. Your total on this set measures how you did on these 28 items. It isn't an NCEES score, and it doesn't predict whether you'll pass. Use it to decide where to start, then let your error log on the larger sets you work in each week take over.
Your results by area (shown after you use Check all answers)
- Circuit Analysis:
- Transmission and Distribution Analysis:
- Protection:
- Electrical Safety:
- Electric Power Devices:
- Rotating Machines:
- Power Electronic Circuits and Control Devices:
- Measurement and Instrumentation:
- General Applications:
Exam setup (tallied separately):
What the PE Power exam tests now
The PE Electrical and Computer: Power exam has 80 questions across nine knowledge areas, under a specification effective beginning with the October 2025 exam. The question ranges below are NCEES's. NCEES notes the topic list is not exhaustive.
| Knowledge area | Questions | What you need to be able to do |
|---|---|---|
| Measurement and Instrumentation | 6–9 | Work through CT and PT ratios and metering; interpret insulation tests (polarization index) and ground-resistance tests |
| General Applications | 8–12 | Lightning and surge protection, lighting design, energy management and demand calculations, grounding |
| Electrical Safety | 10–15 | Find answers fast in the 2020 NEC (wiring methods, hazardous locations, special occupancies and systems); apply NFPA 70E shock and burn rules |
| Circuit Analysis | 10–15 | Three-phase and single-phase circuits, DC circuits, phasor diagrams, per-unit system, symmetrical components |
| Power Electronic Circuits and Control Devices | 5–8 | Converters, inverter-based resources, variable frequency drives; relays, switches, Boolean and ladder logic |
| Rotating Machines | 5–8 | Machine types and applications; motor starting |
| Electric Power Devices | 8–12 | Transformers, capacitors, energy storage, alternative generation such as PV and wind, device testing |
| Transmission and Distribution Analysis | 8–12 | Voltage drop, voltage regulation and support, power factor correction, power quality, fault current, transformer connections, power flow, stability |
| Protection | 10–15 | Overcurrent protection, protective relaying, fuses, breakers and reclosers, coordination |
The three biggest areas, Electrical Safety, Circuit Analysis, and Protection, each carry 10 to 15 questions. The two smallest still carry 5 to 8 each, which is too many to skip on purpose.
Exam format at a glance
| Item | PE Power |
|---|---|
| Delivery | Computer-based, year-round, at Pearson VUE test centers |
| Questions | 80: multiple choice plus alternative item types |
| Exam time | 8 hours |
| Full appointment | 9 hours: 2-minute nondisclosure agreement, 8-minute tutorial, 8-hour exam, 50-minute scheduled break |
| Units | SI and U.S. customary |
| NCEES fee | $400 (your licensing board may charge its own application fee) |
| Results | Usually 7–10 days after the exam |
Source: NCEES Electrical and Computer exam page, Power section; units from the specification.
Alternative item types can include selecting more than one correct option, clicking on part of a graphic, drag and drop, and entering a number (NCEES Examinee Guide, “Exam Content”). That's why several questions above ask for a number instead of offering choices.
Codes and standards supplied on exam day
You don't bring codes. NCEES supplies these editions as searchable PDFs, along with its electronic reference handbook:
| Standard | Edition | Subject |
|---|---|---|
| NFPA 70 (National Electrical Code) | 2020 | Premises wiring |
| NFPA 70E | 2021 | Electrical safety in the workplace |
| ANSI C2 (National Electrical Safety Code) | 2017 | Utility supply and communication lines |
| NFPA 497 | 2021 | Classifying hazardous locations: flammable liquids, gases, and vapors in chemical process areas |
| NFPA 499 | 2021 | Classifying hazardous locations: combustible dusts in chemical process areas |
| NFPA 30B | 2023 | Manufacture and storage of aerosol products |
Two details from the specification matter for how you study:
- Edition counts. A solution that depends on a standard earns credit only if it uses the listed edition. Your workplace may be on the 2023 NEC. The exam is on 2020, so practice in 2020.
- One standard at a time. Each standard is its own chapter, and only one can be open and searched at a time. Know which document to open before you start searching.
What changed in October 2025
If your books, notes, or course were built before October 2025, the fundamentals mostly still apply. The structure and the code editions don't.
| Row label | January 2021 specification | October 2025 specification (current) |
|---|---|---|
| Structure | 4 areas: General Power Engineering; Circuits; Rotating Machines and Electric Power Devices; Transmission and Distribution | 9 areas (table above) |
| NEC | 2017 | 2020 |
| NFPA 70E | 2018 | 2021 |
| NFPA 497 / 499 | 2017 | 2021 |
| NFPA 30B | 2015 | 2023 |
| NESC (ANSI C2) | 2017 | 2017 |
| Newly listed topics | — | Inverter-based resources, electrical energy storage, alternative generation (PV, wind), Boolean logic |
| No longer listed as subtopics | — | Reliability, engineering economics, single-line diagrams, transmission line models, reactors, electrical machine theory |
| Questions | 80 | 80 |
Sources: January 2021 Power specification and October 2025 Power specification.
"No longer listed" isn't the same as "can't appear": NCEES says its topic list isn't exhaustive. But code lookups are the one place an old resource can actively cost you points. If it teaches NEC 2017 section numbers, re-check them in the 2020 edition.
Your 12-week PE Power study plan
Plan by finishing tasks, not by logging hours. If a week runs long because a foundation is weak, slide the calendar rather than skipping the topic. Every week includes problems and a reference-lookup drill (explained below), and from Week 4 on, a short mixed review of earlier weeks.
| Week | Learn | Practice | End-of-week check |
|---|---|---|---|
| 1 | Get set up: download the specification, open the reference handbook in MyNCEES, and pick an approved calculator. Then Circuit Analysis I: three-phase and single-phase circuits, phasors, DC circuits | Questions 1 and 28; handbook drill on the three-phase and per-unit sections | You can solve a balanced three-phase problem without re-deriving the formulas |
| 2 | Circuit Analysis II: per-unit system, symmetrical components | Questions 10 and 19 | You can change base and split unbalanced currents into sequence components |
| 3 | Electric Power Devices I: transformers, transformer connections, capacitors, device testing | Questions 5 and 14 | Mixed transformer and capacitor set |
| 4 | Electrical Safety I: NEC 2020 navigation, wiring methods, grounding (Article 250), motors (Article 430) | Questions 24 and 27; start a weekly mixed review of Weeks 1–3 | Timed code-lookup set |
| 5 | Transmission and Distribution I: voltage drop, regulation and support, power factor correction, power quality | Questions 2 and 20 | Timed T&D calculation set |
| 6 | Transmission and Distribution II: fault current, power flow, stability. Uses per-unit and symmetrical components from Weeks 1–2 | Question 11 | Mixed fault-current set |
| 7 | Protection: overcurrent protection, relaying (differential, distance, undervoltage, pilot), fuses, breakers, reclosers, coordination | Questions 3, 12, and 21 | Protection-heavy mixed set |
| 8 | Electrical Safety II: hazardous locations (NEC 500-series articles, NFPA 497, 499, 30B), special occupancies and systems, NFPA 70E shock and burns, NESC scope | Questions 4, 13, and 22 | Timed code-lookup set across all six standards |
| 9 | Measurement and Instrumentation: CTs, PTs, metering, insulation and ground testing. General Applications: lightning and surge protection, lighting, demand, grounding | Questions 8, 9, 17, 18, 26 | Mixed set across both areas |
| 10 | Rotating Machines: machine types, slip, motor starting. Power electronics: rectifiers, inverter-based resources, VFDs, ladder logic. Energy storage, PV, and wind | Questions 6, 7, 15, 16, 23, 25 | Mixed machines and electronics set |
| 11 | Full simulation: 80 problems in 8 hours, split into two halves with a break. NCEES sells an official practice exam through its exam prep portal | Log every miss | Two weakest areas identified from your log |
| 12 | Repair your two weakest areas; one timed half-length set (40 problems, 4 hours) early in the week; exam logistics | Rework old misses | Light review only in the last 24–48 hours |
Why this order: per-unit, phasors, and symmetrical components feed fault current, and fault current feeds protection, so the calculation chain comes first. Electrical Safety is split into two weeks spread apart because finding things in the codes is a skill that improves with repetition, separate from knowing the material.
8 weeks instead of 12: combine Weeks 1–2, 5–6, 9–10, and 4 with 8. Keep Week 11 as a full simulation.
16 weeks instead of 12: add one extra week after Week 2 for fundamentals, one after Week 8 for codes, one after Week 7 for protection, and one more mixed-practice week before Week 11. Don't just stretch every week equally.
Retaking the exam: if you failed, NCEES gave you a diagnostic report scoring each knowledge area on a 0–15 scale (NCEES Examinee Guide, “Sample Diagnostic Report”). Spend Weeks 1–3 on your two lowest areas, then run the plan from Week 4, keeping the mixed review going.
How to mix practice through the 12 weeks
- Weeks 1–3: mostly topic practice.
- Weeks 4–7: topic practice, plus about a fifth to a quarter of your problems drawn from earlier weeks.
- Weeks 8–10: roughly half repair, half mixed.
- Weeks 11–12: mostly mixed and timed.
This is our editorial structure, not an NCEES rule. You're ready to shift toward mixed, timed work when you can set up problems without relearning them, find what you need in the handbook and codes quickly, and explain why an answer is right.
The reference-lookup drill
Run this on every problem that needs the handbook or a code:
- Name the source first. Is this a handbook equation or a code provision? If it's a code, which one: NEC, 70E, NESC, 497, 499, or 30B?
- Pick your search term before you search. Choose the equipment, condition, article, or variable you're looking for.
- Find it and solve. Use the provision or equation you found, not one from memory.
- Log any miss by type. Was the error in the concept, the navigation, the units, or the arithmetic?
Navigation misses are the cheapest to fix and the easiest to ignore. Your log shows you which kind you're making.
| Problem | Knowledge area | Error type | What went wrong | Correct source and location | Redo date |
|---|---|---|---|---|---|
| Concept / Navigation / Units / Arithmetic |
Scoring, passing, and retakes
There's no published passing percentage. Your number of correct answers is converted to a scaled score, which adjusts for small differences in difficulty between exam forms. That scaled score is compared to the ability level needed to pass. NCEES doesn't publish the passing score, so any "get X out of 80" rule you read online is a guess (NCEES Examinee Guide, “Receiving Exam Results”).
Other scoring rules that change how you test:
- Answer everything. Wrong answers aren't penalized, and there's no partial credit: each question is right or wrong (Examinee Guide, “Understanding Exam Format” and “Receiving Exam Results”).
- Don't hunt for pretest questions. Every exam includes a limited number of unscored pretest items. They're placed randomly and can't be identified, so treat every question as if it counts (Examinee Guide, “Understanding Exam Format”).
- Results are pass or fail. If you fail, the diagnostic report shows how you did in each knowledge area (Examinee Guide, “Receiving Exam Results”).
Pass rates: in NCEES's most recent table (updated July 2026, covering January–June 2026), 62% of 1,344 first-time PE Power takers passed, and 42% of 721 repeat takers passed (NCEES pass rates). Those numbers describe the whole group. They don't predict your result.
Retakes: you can take the same NCEES exam once per testing window and no more than three times in any 12-month period. Your licensing board may be stricter (Examinee Guide, “Testing Opportunities”). Details are in our NCEES retake policy guide.
Exam day: references, calculator, and timing
References. You can't bring books, notes, or your own codes. The handbook and the six standards are on screen as searchable PDFs, and Pearson VUE gives you a reusable booklet and marker for scratch work (Examinee Guide, “Preparing for Exam Day at the Test Center” and “Understanding Exam Format”).
Calculator. Bring one NCEES-approved model. For 2026 exams, the list is any Casio model with "fx-115" or "fx-991" in its name, the HP 33s or HP 35s, or any Texas Instruments model with "TI-30X" or "TI-36X" in its name (NCEES calculator policy). NCEES reviews the list every year. A TI-30XS is also available on screen (Examinee Guide, “Preparing for Exam Day at the Test Center”).
ID. You need one current, physical, government-issued photo ID that matches the name on your appointment. Digital IDs aren't accepted (Examinee Guide, “Preparing for Exam Day at the Test Center”).
Timing. You have 8 hours for 80 questions. Some things to know about how that time works:
- You lose access to the first half after the break. The scheduled break comes after you finish, review, and submit about half the questions. Once you submit them, you can't go back to them (Examinee Guide, “Understanding Exam Format” and “Breaks”). Flag hard questions as you go, and leave yourself time to return to the flags before you submit that half.
- Breaks don't buy you time. Unused scheduled-break time doesn't get added to the exam. Unscheduled breaks come out of your testing time, because the timer keeps running (Examinee Guide, “Breaks” and “NCEES Exam Rules and Agreement”).
- Don't let one search eat your clock. If a code search isn't landing, flag the question and move on.
Final-week checklist
- Rework the misses in your error log instead of chasing new obscure topics.
- Do one mixed set early in the week, not the night before.
- Run a few reference-lookup drills in each of the six standards.
- Check your calculator against the current NCEES list.
- Confirm your appointment time, test center, and ID.
- Ease off in the last 24–48 hours. Don't start a new major topic.
Registering for the PE Power exam
NCEES describes the PE exam as designed for engineers with a minimum of four years of post-college work experience in their discipline. That is not a universal eligibility rule: licensing-board requirements, including experience requirements and when you may sit for the exam, vary by jurisdiction. You register and pay NCEES's $400 fee through MyNCEES. Some boards also require their own application and fee before you can sit for the exam, so check your board's process first (NCEES Electrical and Computer page; board directory). Our NCEES exam registration guide walks through the steps, and our NCEES accommodations guide covers testing accommodations.
Choosing among PE disciplines? Start at our PE exam prep hub. Still preparing for the FE? See FE Electrical and Computer exam prep.
Sources
- NCEES, Electrical and Computer exam page: Power format, fee, availability, results timing, pass rates.
- NCEES, PE Electrical and Computer—Power CBT Exam Specifications, effective October 2025: knowledge areas, question ranges, standards and editions.
- NCEES, Power CBT specification effective January 2021: the previous structure.
- NCEES, Examinee Guide, May 2026: scoring, pretest items, item types, breaks, permitted items, ID, retakes.
- NCEES, calculator policy: approved models for 2026 exams.
- Teaching sources are linked beside each practice question. Code-based answers cite the 2020 NEC, 2021 NFPA 70E, and 2017 NESC by section.
Last verified: October 8, 2026. This date covers the NCEES exam facts, the October 2025 specification, the May 2026 Examinee Guide, the 2026 calculator list, and the July 2026 pass rates.
Prepared by the Castleport Test Prep Editorial Team. How we verify exam claims.
Independence: Castleport Test Prep is an independent exam prep publisher. We are not affiliated with, endorsed by, or approved by NCEES. Exam, credential, and standard names are used to identify their subjects, and trademarks belong to their respective owners. The practice questions on this page are original and unofficial. They are not NCEES exam questions and they don't predict your exam result. Licensing requirements vary by state; confirm yours with your state licensing board.
This guide was drafted with AI assistance and editorial source checks. It has not received a professional engineering review.