Free Journeyman Electrician Practice Test
This free journeyman electrician practice test has 50 original, unofficial questions with answers and explanations, with no signup. The code baseline is 2023 NEC, alongside electrical theory and OSHA questions; Question 50 is a separate 2026 example, not an update of the whole set or a state-specific, full-length exam.
Question 1
Branch circuits & receptacles · 2023 NEC
A 120-volt, 20-ampere branch circuit is protected by a standard circuit breaker (not one listed for 100% continuous operation). The circuit supplies only a continuous load. What is the largest continuous load it can carry?
A. 15 A
B. 16 A
C. 18 A
D. 20 A
Show answer and explanation — Question 1
Answer: B — 16 A
A continuous load is one whose maximum current is expected to continue for 3 hours or more. The breaker has to be rated at least 125% of that load, so flip it around: 20 A ÷ 1.25 = 16 A.
Why not the others? A is below the maximum, not the largest continuous load. C exceeds the 16-A limit for this continuous load. D ignores the 125% requirement entirely.
Reference: 2023 NEC 210.20(A); Article 100, "Continuous Load". NFPA 70, 2023 NEC · 210.20(A) branch-circuit ratings, 2023 NEC (The Electrical Code)
Question 2
Electrical theory & calculations · Electrical theory
A 240-volt heating assembly has two 3.6-kW elements connected in parallel, each running at its rated voltage. What total current flows when both elements are on?
A. 15 A
B. 24 A
C. 60 A
D. 30 A
Show answer and explanation — Question 2
Answer: D — 30 A
Each element draws I = P ÷ E = 3,600 W ÷ 240 V = 15 A. Parallel branch currents add: 15 A + 15 A = 30 A.
Why not the others? A counts only one element. B takes 80% of the right answer for no reason. C divides by 120 V instead of the stated 240 V.
Reference: Watt's law and parallel circuits. Minnesota DLI examination guide: formulas
Question 3
Conductors & overcurrent protection · 2023 NEC
What is the allowable ampacity of a 6 AWG copper THWN conductor in Table 310.16 (30 °C ambient, no more than three current-carrying conductors)?
A. 55 A
B. 75 A
C. 65 A
D. 50 A
Show answer and explanation — Question 3
Answer: C — 65 A
THWN is a 75 °C insulation, so read the 75 °C copper column: 65 A for 6 AWG. (AWG is American Wire Gauge.)
Why not the others? A is the 60 °C value and B the 90 °C value for the same wire. D is the 75 °C value for 8 AWG — one row off.
Reference: 2023 NEC Table 310.16. 2023 ampacity tables, p. 1
Question 4
Services, disconnects & working space · 2023 NEC
A 120/240-volt panelboard (120 volts to ground) has exposed live parts on one side of the working space and no live or grounded parts on the other side (Condition 1). What is the minimum depth of the working space in front of it?
A. 3 ft
B. 30 in.
C. 3½ ft
D. 4 ft
Show answer and explanation — Question 4
Answer: A — 3 ft
A 120/240-volt system is 150 volts or less to ground. At that voltage, Condition 1 requires 3 ft of depth.
Why not the others? B is the minimum width, not depth. C and D occur in higher-voltage rows under particular conditions; at 120 volts to ground, all three conditions require 3 ft.
Reference: 2023 NEC Table 110.26(A)(1). 2023 working-space table, PDF p. 3
Question 5
Wiring methods, raceways & boxes · 2023 NEC
Under the general rule, with no exception applying, electrical metallic tubing (EMT) must be securely fastened within ___ of each outlet box and supported at intervals not exceeding ___.
A. 12 in.; 4½ ft
B. 3 ft; 6 ft
C. 3 ft; 10 ft
D. 12 in.; 8 ft
Show answer and explanation — Question 5
Answer: C — 3 ft; 10 ft
EMT is securely fastened within 3 ft of each box or termination and supported at intervals no greater than 10 ft along the run.
Why not the others? A is the nonmetallic-sheathed cable rule (see Question 24). B and D mix numbers that don't belong to EMT.
Reference: 2023 NEC 358.30(A) and (B); Steel Tube Institute guide, support and fastening, p. 16. NFPA 70, 2023 NEC · Steel Tube Institute guide, pp. 16–17, support/fastening
Question 6
Grounding & bonding · 2023 NEC
A single ground rod is the only grounding electrode at a new service. The installer will proceed without establishing that its resistance to earth is 25 ohms or less. What does the NEC require?
A. Nothing more — one rod is always enough
B. A supplemental electrode
C. A GFCI main breaker
D. Bonding the rod to the gas piping instead of adding an electrode
Show answer and explanation — Question 6
Answer: B — A supplemental electrode
A single rod has to be supplemented by another electrode unless it's shown to have 25 ohms or less resistance to earth. Without establishing that exception, a supplemental electrode is required.
Why not the others? A ignores the 25-ohm condition. C and D aren't substitutes for a grounding electrode.
Reference: 2023 NEC 250.53(A)(2). Minnesota DLI 2023 checklist, p. 7, item 072
Question 7
Electrical theory & calculations · Electrical theory
A 6-ohm resistor and a 3-ohm resistor are connected in parallel. What is the total resistance?
A. 2 Ω
B. 4.5 Ω
C. 9 Ω
D. 18 Ω
Show answer and explanation — Question 7
Answer: A — 2 Ω
For two resistors in parallel, total = (R1 × R2) ÷ (R1 + R2) = (6 × 3) ÷ (6 + 3) = 18 ÷ 9 = 2 Ω. A quick check: parallel resistance is always less than the smallest branch.
Why not the others? B is the average of the two. C is the series total. D is the product without the division.
Reference: Resistance in parallel circuits. Minnesota DLI examination guide: formulas
Question 8
Branch circuits & receptacles · 2023 NEC
A new 125-volt, 20-ampere receptacle for a refrigerator is installed in a dwelling kitchen on a 120-volt, single-phase circuit, 9 ft from the sink. Under the 2023 NEC as published, does it need GFCI (ground-fault circuit interrupter) protection?
A. No — it's more than 6 ft from the sink
B. No — refrigerator receptacles are exempt
C. Only if the refrigerator is portable
D. Yes
Show answer and explanation — Question 8
Answer: D — Yes
The 2023 NEC requires GFCI protection for all 125-volt through 250-volt receptacles in a dwelling kitchen supplied by single-phase circuits of 150 volts or less to ground — not just the countertop receptacles and not just those near the sink.
Why not the others? A applies the 6-ft sink rule, which is a separate item on the list. B and C describe exemptions the NEC doesn't have.
Reference: 2023 NEC 210.8(A)(6). Minnesota DLI 2023 checklist, p. 3, item 025
Question 9
Wiring methods, raceways & boxes · 2023 NEC
A metal outlet box will contain two 12/2 NM cables (each with two insulated 12 AWG conductors plus a bare 12 AWG equipment grounding conductor), one duplex receptacle, and internal cable clamps. What minimum box volume is required?
A. 15.75 in³
B. 18.00 in³
C. 20.25 in³
D. 22.50 in³
Show answer and explanation — Question 9
Answer: B — 18.00 in³
Count volume allowances: 4 insulated conductors = 4; the two grounding conductors = 1 (up to four count as one); the receptacle yoke = 2; the internal clamps = 1. That's 8 allowances × 2.25 in³ for 12 AWG = 18.00 in³. (NM is nonmetallic-sheathed cable.)
Why not the others? A forgets the clamps. C counts the two grounding conductors as two allowances. D over-counts further.
Reference: 2023 NEC 314.16(B) and Table 314.16(B)(1) (renumbered in 2023). Minnesota DLI 2023 checklist, p. 5, item 046 and box-fill table
Question 10
Motors · 2023 NEC
A continuous-duty, single-speed, normal-speed and normal-torque 10-hp, 460-volt, three-phase squirrel-cage motor has a nameplate current of 13 A. For this question, use 14 A as its table full-load current. What is the minimum ampacity of the branch-circuit conductors?
A. 14.0 A
B. 16.25 A
C. 17.5 A
D. 35 A
Show answer and explanation — Question 10
Answer: C — 17.5 A
For this motor, branch-circuit conductors are sized from the table current, not the nameplate: 14 A × 1.25 = 17.5 A.
Why not the others? B uses the nameplate (13 × 1.25) — the classic trap. A leaves out the 125%. D is the base 250% breaker rating calculated in Question 19.
Reference: 2023 NEC 430.6(A)(1), 430.22, Table 430.250. EC&M, NEC Requirements for Motors, Part 1
Question 11
Conductors & overcurrent protection · 2023 NEC
A 6 AWG copper THWN-2 conductor (90 °C insulation, Table 310.16 value 75 A) runs through a 40 °C ambient with no more than three current-carrying conductors. What is its temperature-corrected ampacity, before checking terminations?
A. 75 A
B. 65 A
C. 60 A
D. 68.25 A
Show answer and explanation — Question 11
Answer: D — 68.25 A
The correction factor for 36–40 °C in the 90 °C column is 0.91. So 75 A × 0.91 = 68.25 A. That's an intermediate value; the conductor still has to meet the termination temperature limit (see Question 39).
Why not the others? A skips the correction. B is the 75 °C table value, not a corrected 90 °C value. C applies an 80% factor that belongs to conductor-count adjustment, not this ambient-temperature correction.
Reference: 2023 NEC Table 310.16 and Table 310.15(B)(1)(1). 2023 ampacity tables, pp. 1–2
Question 12
Grounding & bonding · 2023 NEC
A grounding electrode conductor connects only to a driven ground rod and does not extend to other electrodes. Regardless of service size, the NEC never requires this conductor to be larger than what copper size?
A. 8 AWG
B. 4 AWG
C. 6 AWG
D. 2 AWG
Show answer and explanation — Question 12
Answer: C — 6 AWG
When the conductor is the sole connection to a rod, pipe, or plate electrode, it never has to be larger than 6 AWG copper, even on a large service.
Why not the others? B and D come from Table 250.66 rows that don't apply to this portion of the conductor. A is smaller than the 6 AWG cap.
Reference: 2023 NEC 250.66(A). NFPA 70, 2023 NEC
Question 13
Branch circuits & receptacles · 2023 NEC
A dwelling living room has one continuous 15-ft wall space with no doorways, fireplaces, or other breaks. Assume no receptacles around adjoining corners serve this wall. Measured from the left end, which receptacle layout meets the spacing rule for that wall?
A. One receptacle at 7.5 ft
B. Receptacles at 0 ft and 15 ft
C. Receptacles at 3 ft and 12 ft
D. One receptacle at 6 ft
Show answer and explanation — Question 13
Answer: C — Receptacles at 3 ft and 12 ft
No point along the floor line can be more than 6 ft from a receptacle. With receptacles at 3 ft and 12 ft, check the two ends (3 ft away) and the middle at 7.5 ft (4.5 ft away). Everything is within 6 ft.
Why not the others? A leaves both ends 7.5 ft away. B leaves the middle 7.5 ft away. D leaves the right end 9 ft away.
Reference: 2023 NEC 210.52(A)(1). Minnesota DLI 2023 checklist, p. 2, item 016
Question 14
Services, disconnects & working space · 2023 NEC
What is the minimum rating of the service disconnecting means for a one-family dwelling when the calculated load does not require a larger rating?
A. 100 A
B. 60 A
C. 150 A
D. 200 A
Show answer and explanation — Question 14
Answer: A — 100 A
One-family dwellings need a service disconnect rated at least 100 amperes, 3-wire.
Why not the others? B is below the minimum. C and D are common larger sizes, not the minimum.
Reference: 2023 NEC 230.79(C). NFPA 70, 2023 NEC
Question 15
Electrical theory & calculations · Electrical theory
A 6-ohm resistor and a 3-ohm resistor are connected in series across 120 volts. To the nearest tenth of an ampere, what current flows?
A. 13.3 A
B. 20 A
C. 40 A
D. 60 A
Show answer and explanation — Question 15
Answer: A — 13.3 A
Series resistance adds: 6 + 3 = 9 Ω. Then I = E ÷ R = 120 ÷ 9 ≈ 13.3 A. The same current flows through both resistors.
Why not the others? B divides by the 6-Ω resistor alone, C by the 3-Ω resistor alone, and D by the 2-Ω parallel total.
Reference: Ohm's law; resistance in series circuits. Minnesota DLI examination guide: formulas
Question 16
Wiring methods, raceways & boxes · 2023 NEC
Under the general Chapter 9, Table 1 rule, what is the maximum percent fill of a conduit's cross-sectional area for three or more conductors (not a short nipple)?
A. 53%
B. 31%
C. 60%
D. 40%
Show answer and explanation — Question 16
Answer: D — 40%
Over two conductors: 40% of the conduit's internal area.
Why not the others? A is the limit for one conductor and B for two. C is the allowance for qualifying nipples 24 in. or shorter.
Reference: 2023 NEC Chapter 9, Table 1 and its notes. NFPA 70, 2023 NEC · Steel Tube Institute guide, pp. 7–8, nipple fill
Question 17
Wiring methods, raceways & boxes · 2023 NEC
An NM cable runs through a hole bored in a wood stud. The edge of the hole is ¾ in. from the nearest face of the stud, and the cable can't be relocated. Which option meets the general protection rule?
A. A plastic identification tag
B. A steel plate at least 1/16 in. thick covering the area
C. Extra electrical tape around the cable
D. None, because the hole is centered vertically
Show answer and explanation — Question 17
Answer: B — A steel plate at least 1/16 in. thick covering the area
The edge of a bored hole must be at least 1¼ in. from the nearest edge of the wood member. When that distance can't be met, the general rule requires a steel plate or sleeve at least 1/16 in. thick to protect the cable from nails and screws. The exception permits a thinner steel plate if it is listed and marked for that purpose.
Why not the others? A and C don't stop a nail or screw. D confuses vertical position with the required 1¼-in. setback from the face.
Reference: 2023 NEC 300.4(A)(1). Minnesota DLI 2023 checklist, p. 4, item 037 · NFPA 70, 2023 NEC
Question 18
Electrical theory & calculations · Electrical theory
A balanced 30-kVA load is supplied at 208 volts line-to-line, three-phase. To the nearest tenth of an ampere, what is the line current?
A. 48.1 A
B. 144.2 A
C. 83.3 A
D. 250 A
Show answer and explanation — Question 18
Answer: C — 83.3 A
Three-phase current = VA ÷ (E × √3) = 30,000 ÷ (208 × 1.732) = 83.3 A.
Why not the others? B forgets √3 and treats it as single-phase. A divides by 3 instead of √3. D divides by 120 volts, single-phase.
Reference: Volt-amperes and three-phase calculations. Minnesota DLI examination guide: formulas
Question 19
Motors · 2023 NEC
A continuous-duty, single-speed, normal-speed and normal-torque 10-hp, 460-volt, three-phase squirrel-cage motor has a table full-load current of 14 A. What is the maximum inverse-time circuit-breaker rating for branch-circuit short-circuit and ground-fault protection before applying either the next-size-up or motor-starting-current exception?
A. 17.5 A
B. 25 A
C. 50 A
D. 35 A
Show answer and explanation — Question 19
Answer: D — 35 A
For this motor type, an inverse-time breaker may be up to 250% of table current: 14 × 2.5 = 35 A, which is already a standard size.
Why not the others? B is the dual-element fuse limit (175%, 24.5 A) rounded up. A is the conductor ampacity. C is over the 250% limit.
Reference: 2023 NEC 430.52(C)(1), Table 430.52(C)(1), and Table 240.6(A). 2023 NEC Table 430.52(C)(1), reproduced code text and table · NFPA 70, 2023 NEC
Question 20
Conductors & overcurrent protection · 2023 NEC
Unless a specific exception applies, what is the maximum overcurrent protection for 14 AWG copper conductors?
A. 15 A
B. 20 A
C. 25 A
D. 30 A
Show answer and explanation — Question 20
Answer: A — 15 A
The small-conductor rule caps 14 AWG copper at 15 A (12 AWG at 20 A, 10 AWG at 30 A), even though Table 310.16 lists higher ampacities for these sizes.
Why not the others? B is the limit for 12 AWG and D for 10 AWG. C is the 75 °C table value for 12 AWG, not a protection limit.
Reference: 2023 NEC 240.4(D). 2023 ampacity tables, p. 1
Question 21
Grounding & bonding · 2023 NEC
With ordinary soil and no rock-bottom exception applying, a ground rod must be installed so that at least ___ of its length is in contact with the soil.
A. 8 ft
B. 6 ft
C. 10 ft
D. 12 ft
Show answer and explanation — Question 21
Answer: A — 8 ft
At least 8 ft of the rod has to be in contact with soil.
Why not the others? B is the minimum spacing between two rods. C and D exceed the required minimum soil-contact length.
Reference: 2023 NEC 250.53(A)(3) and (A)(4). NFPA 70, 2023 NEC
Question 22
Services, disconnects & working space · 2023 NEC
Under the general rule, with no height exception applying, circuit breakers must be installed so that the center of the operating handle's grip, in its highest position, is no more than ___ above the floor or working platform.
A. 5 ft 6 in.
B. 6 ft 7 in.
C. 6 ft
D. 7 ft
Show answer and explanation — Question 22
Answer: B — 6 ft 7 in.
The limit is 2.0 m, or 6 ft 7 in., measured to the center of the handle grip in its highest position.
Why not the others? A, C, and D aren't the NEC figure.
Reference: 2023 NEC 240.24(A). NFPA 70, 2023 NEC
Question 23
Electrical theory & calculations · Electrical theory
A motor load with sinusoidal voltage and current draws 10 kVA at a power factor of 0.8. What is its true power?
A. 8 kW
B. 12.5 kW
C. 10 kW
D. 6 kW
Show answer and explanation — Question 23
Answer: A — 8 kW
True power = apparent power × power factor = 10 kVA × 0.8 = 8 kW.
Why not the others? B divides instead of multiplying. C ignores the power factor. D uses the number from reactive power (6 kVAR, from the 6-8-10 triangle), not true power.
Reference: Volt-amperes and power factor. Minnesota DLI examination guide: formulas
Question 24
Wiring methods, raceways & boxes · 2023 NEC
Under the general rule, with no exception applying and with cable clamps at the enclosure entries, NM cable run along framing must be secured at intervals not exceeding ___ and within ___ of every cable entry into an enclosure.
A. 3 ft; 8 in.
B. 6 ft; 12 in.
C. 10 ft; 3 ft
D. 4½ ft; 12 in.
Show answer and explanation — Question 24
Answer: D — 4½ ft; 12 in.
NM cable: supports no more than 4½ ft apart, and within 12 in. of each cable entry into a box or other enclosure.
Why not the others? C is the EMT rule. A and B use the wrong along-run support interval for NM cable.
Reference: 2023 NEC 334.30. Minnesota DLI 2023 checklist, p. 4, item 034
Question 25
Branch circuits & receptacles · 2023 NEC
What is the minimum number of 20-ampere small-appliance branch circuits required for the kitchen and related areas of a dwelling?
A. One
B. Two
C. Three
D. Four
Show answer and explanation — Question 25
Answer: B — Two
At least two 20-ampere small-appliance branch circuits. That's a minimum for the receptacle outlets — some appliances still need their own circuits.
Why not the others? A is one short. C and D exceed the minimum.
Reference: 2023 NEC 210.11(C)(1). Minnesota DLI 2023 checklist, p. 1, item 010
Question 26
Grounding & bonding · 2023 NEC
What is the minimum table size of a copper equipment grounding conductor for a circuit protected by a 60-ampere overcurrent device, before any required upsizing or other special provision?
A. 10 AWG
B. 12 AWG
C. 8 AWG
D. 6 AWG
Show answer and explanation — Question 26
Answer: A — 10 AWG
Table 250.122 gives 10 AWG copper for overcurrent devices rated 60 A.
Why not the others? B is the 20-A size. C is the 100-A size and D the 200-A size.
Reference: 2023 NEC Table 250.122. NFPA 70, 2023 NEC
Question 27
Wiring methods, raceways & boxes · 2023 NEC
A raceway is installed above grade in an outdoor wet location. How is the interior of that raceway classified?
A. Dry
B. Damp only
C. Wet
D. Unclassified
Show answer and explanation — Question 27
Answer: C — Wet
The interior of a raceway in a wet location above grade is itself a wet location. Water gets in through condensation and fittings, so conductors inside must be suitable for wet locations.
Why not the others? A and B assume the raceway keeps water out. D isn't a classification the rule uses.
Reference: 2023 NEC 300.9. Minnesota DLI 2023 checklist, p. 6, item 060
Question 28
Special locations & safe work · OSHA 29 CFR 1910
A workplace circuit has 480 volts between conductors and 480 volts from one ungrounded conductor to ground. A proposed circuit breaker is slash-rated 480Y/277 V. Considering voltage limits only, is it suitable?
A. Yes, because both ratings include 480 V
B. Yes, if the ampere rating is high enough
C. No, because the voltage to ground exceeds 277 V
D. Yes, if the enclosure is grounded
Show answer and explanation — Question 28
Answer: C — No, because the voltage to ground exceeds 277 V
A slash rating has two limits: the lower number caps the voltage from any conductor to ground, and the higher number caps the voltage between conductors. Here 480 V to ground is over the 277-V limit.
Why not the others? A reads only the higher number. B and D don't change the voltage limits. (This question checks voltage only — interrupting rating and other requirements are separate.)
Reference: OSHA 29 CFR 1910.304(f)(1)(ix). OSHA 29 CFR 1910.304(f)(1)(ix)
Question 29
Wiring methods, raceways & boxes · 2023 NEC
Rigid metal conduit carrying a 120/240-volt feeder is buried under a lawn with no vehicle traffic and no other special conditions. What is the minimum cover?
A. 6 in.
B. 12 in.
C. 18 in.
D. 24 in.
Show answer and explanation — Question 29
Answer: A — 6 in.
Rigid metal conduit (column 2 of the burial table) needs only 6 in. of cover in this general location.
Why not the others? D is the value for direct-burial cable. B is the value for GFCI-protected residential 120-volt branch circuits of 20 A or less. C isn't the rigid metal conduit value.
Reference: 2023 NEC Table 300.5(A) (renumbered from Table 300.5 in 2023). Minnesota DLI 2023 checklist, p. 7, item 075 and burial table
Question 30
Electrical theory & calculations · Electrical theory
A 120-volt, single-phase branch circuit uses 12 AWG copper (6,530 circular mils). The load is 16 A, 100 ft one way from the panel. Using the supplied exercise value K = 12.9 ohm-circular-mil/ft for copper, what is the approximate voltage drop?
A. 1.6 V
B. 3.2 V
C. 12.6 V
D. 6.3 V
Show answer and explanation — Question 30
Answer: D — 6.3 V
VD = (2 × K × I × D) ÷ CM = (2 × 12.9 × 16 × 100) ÷ 6,530 = 6.3 V, about 5.3% of 120 V. The 2 is there because current travels out and back.
Why not the others? B leaves out the 2. A halves it again. C doubles the correct answer.
Reference: Approximate single-phase voltage-drop formula; supplied K and circular-mil values. Minnesota DLI examination guide: formulas
Question 31
Motors · 2023 NEC
Separate current-responsive overload protection for a continuous-duty motor rated more than 1 hp is sized from which value?
A. The Table 430.250 full-load current
B. The motor nameplate full-load current
C. The branch-circuit breaker rating
D. 125% of the conductor ampacity
Show answer and explanation — Question 31
Answer: B — The motor nameplate full-load current
Overloads protect the actual motor, so they're based on its nameplate current. For the ordinary motors in Questions 10 and 19, conductors and short-circuit protection use the table value.
Why not the others? A is the value used for those ordinary motors’ conductors and short-circuit/ground-fault protection. C and D mix up different parts of the motor circuit.
Reference: 2023 NEC 430.6(A)(2) and 430.32(A)(1). EC&M, NEC Requirements for Motors, Part 1
Question 32
Grounding & bonding · 2023 NEC
The service-entrance conductors are 3/0 AWG copper. What minimum size copper grounding electrode conductor does Table 250.66 require (with none of the electrode-specific exceptions in 250.66(A) through (C) applying)?
A. 4 AWG
B. 6 AWG
C. 2 AWG
D. 1/0 AWG
Show answer and explanation — Question 32
Answer: A — 4 AWG
The copper row for 2/0 or 3/0 service conductors gives a 4 AWG copper grounding electrode conductor.
Why not the others? B is the row for 1 or 1/0 AWG service conductors. C starts above 3/0. D is for much larger services.
Reference: 2023 NEC Table 250.66. Minnesota DLI 2023 checklist, p. 7, grounding-electrode-conductor table
Question 33
Services, disconnects & working space · 2023 NEC
What is the minimum vertical clearance of 120/240-volt service-drop conductors over a public street subject to truck traffic?
A. 10 ft
B. 12 ft
C. 15 ft
D. 18 ft
Show answer and explanation — Question 33
Answer: D — 18 ft
18 ft over public streets, alleys, roads, and parking areas subject to truck traffic.
Why not the others? B applies over residential property and driveways at 300 volts or less to ground. A applies only in limited pedestrian areas for certain cables. C is for residential areas above 300 volts to ground.
Reference: 2023 NEC 230.24(B). NFPA 70, 2023 NEC
Question 34
Branch circuits & receptacles · 2023 NEC
Dwelling kitchen countertop receptacles must be placed so that no point along the wall line (in wall spaces 12 in. or wider) is more than ___ from a receptacle outlet.
A. 24 in.
B. 12 in.
C. 18 in.
D. 48 in.
Show answer and explanation — Question 34
Answer: A — 24 in.
24 in. measured horizontally, which is why countertop receptacles often end up about 4 ft apart.
Why not the others? D is that typical spacing, not the rule's distance. B is the minimum wall-space width that needs a receptacle. C is not the distance specified by this rule.
Reference: 2023 NEC 210.52(C)(1). Minnesota DLI 2023 checklist, p. 2, item 017
Question 35
Conductors & overcurrent protection · 2023 NEC
Nine current-carrying 12 AWG THHN copper conductors are installed in one raceway at 30 °C ambient. What is the adjusted ampacity of each conductor before checking termination limits?
A. 17.5 A
B. 24 A
C. 21 A
D. 15 A
Show answer and explanation — Question 35
Answer: C — 21 A
Start from the 90 °C column for THHN: 30 A. Seven to nine current-carrying conductors take a 70% adjustment: 30 × 0.70 = 21 A. The small-conductor rule still limits the breaker to 20 A. The termination and load requirements still apply.
Why not the others? A applies 70% to the 75 °C value. B uses the 80% factor for 4–6 conductors. D is 50%, the factor for 10–20 conductors.
Reference: 2023 NEC Table 310.16, Table 310.15(C)(1), 240.4(D). 2023 ampacity tables, pp. 1–2
Question 36
Grounding & bonding · 2023 NEC
A new 120/240-volt feeder in nonmetallic conduit supplies a detached workshop, and a grounding electrode system is installed at the workshop. What does the NEC require for an equipment grounding conductor?
A. None — the local electrodes replace it
B. Run one with the feeder and connect it at the workshop's disconnecting means, which is also connected to the grounding electrode system
C. None, as long as the feeder has a neutral
D. Only if the workshop has a second floor
Show answer and explanation — Question 36
Answer: B — Run one with the feeder and connect it at the workshop's disconnecting means, which is also connected to the grounding electrode system
A new feeder to a detached building must include an equipment grounding conductor run with the supply conductors. Ground rods at the building don't provide the low-impedance path back to the source that clears faults.
Why not the others? A substitutes local electrodes for the feeder's equipment grounding conductor. C substitutes the neutral; neither meets the requirement for this new feeder. D is invented.
Reference: 2023 NEC 250.32(B)(1). Minnesota DLI 2023 checklist, p. 6, item 068
Question 37
Electrical theory & calculations · Electrical theory
What is the full-load primary current of a balanced 75-kVA, three-phase transformer with a 480-volt line-to-line primary, to the nearest tenth of an ampere?
A. 90.2 A
B. 156.3 A
C. 208.2 A
D. 52.1 A
Show answer and explanation — Question 37
Answer: A — 90.2 A
I = VA ÷ (E × √3) = 75,000 ÷ (480 × 1.732) = 90.2 A.
Why not the others? B forgets √3. C uses 208 volts — that's the secondary current of a 480–208Y/120-volt unit. D divides by 3 instead of √3.
Reference: Transformer ratings and three-phase calculations. Minnesota DLI examination guide: formulas
Question 38
Wiring methods, raceways & boxes · 2023 NEC
Two ordinary branch-circuit neutral conductors (not parallel conductors) are being terminated in a panelboard. Which arrangement is required?
A. Both under one terminal, because they're the same size
B. Each neutral in its own individual terminal
C. Both under one terminal, because their breakers are next to each other
D. Both under a grounding-bar terminal that's rated for two grounds
Show answer and explanation — Question 38
Answer: B — Each neutral in its own individual terminal
Each grounded (neutral) conductor in a panelboard terminates in its own individual terminal.
Why not the others? A and C give reasons that don't matter to this rule. D confuses a terminal's rating for grounding conductors with neutral terminations.
Reference: 2023 NEC 408.41. Minnesota DLI 2023 checklist, p. 4, item 043
Question 39
Conductors & overcurrent protection · 2023 NEC
An ordinary nonmotor 30-ampere circuit uses 10 AWG THHN copper. The equipment terminals have no temperature marking. Which Table 310.16 column limits the conductor's ampacity at the terminations?
A. 75 °C
B. 90 °C
C. 60 °C
D. Whatever the insulation is rated for
Show answer and explanation — Question 39
Answer: C — 60 °C
For ordinary nonmotor circuits rated 100 A or less (or 14 through 1 AWG conductors), terminations are limited to the 60 °C column unless the equipment is listed and identified for higher. 10 AWG at 60 °C is 30 A.
Why not the others? A needs equipment marked for 75 °C. B and D are the conductor's insulation rating — useful as a starting point for correction and adjustment, but not at unmarked terminals.
Reference: 2023 NEC 110.14(C)(1)(a). NFPA 70, 2023 NEC · 2023 ampacity tables, p. 1
Question 40
Branch circuits & receptacles · 2023 NEC
A fixed 4,500-watt, 240-volt, 50-gallon storage water heater is being installed with suitable conductors and a standard breaker, not a 100%-rated assembly. Its listing does not require a higher breaker rating. What is the smallest standard overcurrent device rating that meets the 125% requirement?
A. 20 A
B. 30 A
C. 25 A
D. 40 A
Show answer and explanation — Question 40
Answer: C — 25 A
Current = 4,500 ÷ 240 = 18.75 A. Storage water heaters of 120 gallons or less need an overcurrent device rated at least 125% of the heater's rating: 18.75 × 1.25 = 23.4375 A. The next standard size up is 25 A.
Why not the others? A forgets the 125%. B and D exceed the calculated minimum; that does not establish that either is permitted for a particular installation.
Reference: 2023 NEC 422.13 and Table 240.6(A). IAEI Magazine, Using NEC Article 422 · NFPA 70, 2023 NEC
Question 41
Grounding & bonding · 2023 NEC
A new building has both a qualifying concrete-encased electrode and a qualifying metal underground water pipe. How must these electrodes be handled?
A. Use the cheaper one and ignore the other
B. Keep them isolated from each other
C. Use neither if the panel enclosure is metal
D. Bond them together to form the grounding electrode system
Show answer and explanation — Question 41
Answer: D — Bond them together to form the grounding electrode system
All qualifying electrodes present at a building are bonded together to form one grounding electrode system.
Why not the others? A, B, and C each leave a present electrode out or isolate it, which the rule doesn't allow.
Reference: 2023 NEC 250.50. Minnesota DLI 2023 checklist, p. 6, item 069
Question 42
Branch circuits & receptacles · 2023 NEC
A new 125-volt, 20-ampere dwelling receptacle outdoors is exposed to the weather and will have a cord plugged in while in use. Which option meets the weather-protection requirements?
A. Standard receptacle with a cover that's weatherproof only when unplugged
B. Weather-resistant receptacle with an extra-duty cover that's weatherproof with a plug inserted
C. Standard receptacle with an in-use cover
D. Weather-resistant receptacle with a cover that's weatherproof only when unplugged
Show answer and explanation — Question 42
Answer: B — Weather-resistant receptacle with an extra-duty cover that's weatherproof with a plug inserted
Two things are required here: a listed weather-resistant receptacle, and an enclosure that stays weatherproof with the plug inserted (an extra-duty "in-use" cover).
Why not the others? A and C miss the weather-resistant receptacle. A and D miss the in-use cover.
Reference: 2023 NEC 406.9(B)(1). Minnesota DLI 2023 checklist, p. 2, item 011
Question 43
Services, disconnects & working space · 2023 NEC
A panelboard is 20 in. wide. What is the minimum width of the working space in front of it?
A. 20 in.
B. 24 in.
C. 36 in.
D. 30 in.
Show answer and explanation — Question 43
Answer: D — 30 in.
The working space must be at least 30 in. wide, or the width of the equipment if that's greater.
Why not the others? A matches the equipment but is below the 30-in. minimum. B and C aren't the rule.
Reference: 2023 NEC 110.26(A)(2). Minnesota DLI 2023 checklist, p. 6, item 065
Question 44
Special locations & safe work · Electrical theory
In a simplified two-wire example, 5.000 A flows out through a GFCI's monitored supply conductor and 4.994 A returns on its monitored return conductor. What does that comparison show?
A. A 6-A overload
B. No difference, since both round to 5 A
C. A 0.006-V voltage drop
D. A 6-mA current imbalance
Show answer and explanation — Question 44
Answer: D — A 6-mA current imbalance
5.000 A − 4.994 A = 0.006 A, which is 6 milliamperes. A GFCI compares the current going out with the current coming back; a difference means some current is taking another path — possibly through a person.
Why not the others? A and C use the wrong units. B rounds away exactly the difference a GFCI is built to detect.
Reference: GFCI operating principle. OSHA eTool, Ground-Fault Circuit Interrupters
Question 45
Grounding & bonding · 2023 NEC
Under the general identification rule for wire-type equipment grounding conductors, which option is NOT permitted without reidentification?
A. Green insulation
B. Green with one or more yellow stripes
C. Bare, with no insulation or covering
D. White insulation
Show answer and explanation — Question 45
Answer: D — White insulation
Equipment grounding conductors may be bare, or insulated or covered in green or green with yellow stripes. White and gray identify the grounded conductor, usually the neutral.
Why not the others? A, B, and C are all permitted identifications.
Reference: 2023 NEC 250.119; 200.6. NFPA 70, 2023 NEC
Question 46
Special locations & safe work · 2023 NEC
A 125-volt, 20-ampere general-purpose receptacle, supplied at 120 volts to ground, is 15 ft from the inside wall of a permanently installed swimming pool. Under the 2023 NEC, which statement about GFCI protection is correct?
A. GFCI protection is required.
B. Protection is required only if the receptacle supplies the pool pump.
C. Tamper-resistant construction replaces GFCI protection.
D. Weather-resistant construction replaces GFCI protection.
Show answer and explanation — Question 46
Answer: A — GFCI protection is required.
This receptacle is within 20 ft of the inside pool wall and falls within the voltage and ampere limits of 680.22(A)(4). At the stated 120 volts to ground, it requires GFCI protection.
Why not the others? B incorrectly limits the rule to pump receptacles. C and D describe different protective features; neither replaces GFCI protection.
Reference: 2023 NEC 680.22(A)(4); GFCI/SPGFCI distinction in 680.5. Leviton Captain Code 2023, 680.22(A)
Question 47
Special locations & safe work · OSHA 29 CFR 1910
During maintenance covered by OSHA 1910.333, a machine has been stopped only with its control-circuit pushbutton. Can that pushbutton be the sole means of deenergizing the equipment before work on exposed electrical parts?
A. Yes, if its indicator lamp is off
B. No
C. Yes, if the motor has stopped turning
D. Yes, if a coworker watches the button
Show answer and explanation — Question 47
Answer: B — No
Control-circuit devices — pushbuttons, selector switches, interlocks — may not be the only means of deenergizing. The equipment has to be disconnected from its energy sources and the required lockout/tagout steps followed. A qualified person must also test the circuit elements and parts to verify that they are deenergized before they are treated as deenergized.
Why not the others? A, C, and D describe a stopped machine, not an isolated one.
Reference: OSHA 29 CFR 1910.333(b)(2)(ii)(B) and (b)(2)(iv)(B). OSHA 29 CFR 1910.333 — deenergizing and verification
Question 48
Grounding & bonding · 2023 NEC
A grounded AC service has one service disconnect panel feeding several downstream feeder panels (no separately derived systems). Where is the main bonding jumper installed?
A. In every downstream feeder panel
B. Only in the most distant feeder panel
C. At the service, in the service disconnect enclosure
D. In any junction box that's convenient
Show answer and explanation — Question 48
Answer: C — At the service, in the service disconnect enclosure
The main bonding jumper connects the neutral to the equipment grounding system at the service. Downstream panels keep neutrals and grounds separate.
Why not the others? A and B would put neutral-to-ground bonds downstream of the service. D isn't a location the rule allows.
Reference: 2023 NEC 250.24(B) and 250.28. Minnesota DLI 2023 checklist, p. 6, item 067
Question 49
Wiring methods, raceways & boxes · Electrical theory
In this exercise, a raceway has an allowable fill area of 0.200 in² (the fill percentage has already been applied). Two installed conductors take up 0.040 in² each. What is the maximum number of additional conductors of 0.030 in² each that can be added without exceeding the allowance?
A. 3
B. 4
C. 5
D. 6
Show answer and explanation — Question 49
Answer: B — 4
Remaining area = 0.200 − (2 × 0.040) = 0.120 in². Then 0.120 ÷ 0.030 = 4 conductors.
Why not the others? A leaves usable space empty. C and D go over the allowance. Don't apply the fill percentage a second time — the stem already did.
Reference: Conduit fill calculations (area-summing method); supplied exercise values. Minnesota DLI examination guide: formulas
Question 50
Branch circuits & receptacles · 2026 NEC (edition check)
Using the 2026 NEC, what is the general lighting load of a dwelling with a calculated floor area of 2,000 square feet for a service or feeder calculation, before demand factors?
A. 3,000 VA
B. 6,000 VA
C. 4,000 VA
D. 8,000 VA
Show answer and explanation — Question 50
Answer: C — 4,000 VA
The 2026 NEC lowered the dwelling unit load to 2 VA per square foot: 2,000 × 2 = 4,000 VA. Under the 2023 NEC, the answer would be B — 3 VA per square foot, or 6,000 VA. That's why you need to know your exam's edition. The 2026 code still uses 3 VA per square foot to figure the minimum number of branch circuits, just not the service or feeder load.
Why not the others? A and D don't match either edition's unit load. B is the 2023 answer.
Reference: 2026 NEC 120.41 and 120.13 (load calculations moved from Article 220 to Article 120); 2023 NEC 220.41. EC&M, Changes to Dwelling Unit Calculations in the 2026 NEC (May 19, 2026)
Your results
Count your correct answers out of 50, then use the key below to see which topic groups your misses came from. A blank answer counts as a miss. Your percentage is correct answers ÷ 50 × 100; 40 correct answers is 80%.
| Question | Answer | Topic group |
|---|---|---|
| 1 | B | Branch circuits & receptacles |
| 2 | D | Electrical theory & calculations |
| 3 | C | Conductors & overcurrent protection |
| 4 | A | Services, disconnects & working space |
| 5 | C | Wiring methods, raceways & boxes |
| 6 | B | Grounding & bonding |
| 7 | A | Electrical theory & calculations |
| 8 | D | Branch circuits & receptacles |
| 9 | B | Wiring methods, raceways & boxes |
| 10 | C | Motors |
| 11 | D | Conductors & overcurrent protection |
| 12 | C | Grounding & bonding |
| 13 | C | Branch circuits & receptacles |
| 14 | A | Services, disconnects & working space |
| 15 | A | Electrical theory & calculations |
| 16 | D | Wiring methods, raceways & boxes |
| 17 | B | Wiring methods, raceways & boxes |
| 18 | C | Electrical theory & calculations |
| 19 | D | Motors |
| 20 | A | Conductors & overcurrent protection |
| 21 | A | Grounding & bonding |
| 22 | B | Services, disconnects & working space |
| 23 | A | Electrical theory & calculations |
| 24 | D | Wiring methods, raceways & boxes |
| 25 | B | Branch circuits & receptacles |
| 26 | A | Grounding & bonding |
| 27 | C | Wiring methods, raceways & boxes |
| 28 | C | Special locations & safe work |
| 29 | A | Wiring methods, raceways & boxes |
| 30 | D | Electrical theory & calculations |
| 31 | B | Motors |
| 32 | A | Grounding & bonding |
| 33 | D | Services, disconnects & working space |
| 34 | A | Branch circuits & receptacles |
| 35 | C | Conductors & overcurrent protection |
| 36 | B | Grounding & bonding |
| 37 | A | Electrical theory & calculations |
| 38 | B | Wiring methods, raceways & boxes |
| 39 | C | Conductors & overcurrent protection |
| 40 | C | Branch circuits & receptacles |
| 41 | D | Grounding & bonding |
| 42 | B | Branch circuits & receptacles |
| 43 | D | Services, disconnects & working space |
| 44 | D | Special locations & safe work |
| 45 | D | Grounding & bonding |
| 46 | A | Special locations & safe work |
| 47 | B | Special locations & safe work |
| 48 | C | Grounding & bonding |
| 49 | B | Wiring methods, raceways & boxes |
| 50 | C | Branch circuits & receptacles |
Your percentage describes how you did on these 50 questions. It isn't an official score, and it can't predict whether you'll pass. Some groups have only three or four questions, so read a group result as "worth another look," not as a measurement.
| Topic group | Questions | Count |
|---|---|---|
| Electrical theory & calculations | 2, 7, 15, 18, 23, 30, 37 | 7 |
| Conductors & overcurrent protection | 3, 11, 20, 35, 39 | 5 |
| Wiring methods, raceways & boxes | 5, 9, 16, 17, 24, 27, 29, 38, 49 | 9 |
| Branch circuits & receptacles | 1, 8, 13, 25, 34, 40, 42, 50 | 8 |
| Grounding & bonding | 6, 12, 21, 26, 32, 36, 41, 45, 48 | 9 |
| Services, disconnects & working space | 4, 14, 22, 33, 43 | 5 |
| Motors | 10, 19, 31 | 3 |
| Special locations & safe work | 28, 44, 46, 47 | 4 |
| Total | 50 |
Which NEC edition is your exam on?
The one your state's current candidate bulletin names. It isn't automatically the newest edition. Use the exam reference rule for your test date, not just the code adopted for installation work.
These three official sources illustrate the difference:
| State | What the official source says | Checked |
|---|---|---|
| Texas | TDLR's exam page identifies the 2026 NEC. Its reference-material rules allow any soft-bound NEC edition, but an older permitted book does not change the edition on which the questions are based. (TDLR, Reference Materials) | Sept. 28, 2026 |
| Minnesota | DLI identifies the 2026 NEC for electrical licensing exams. Check the exam notice rather than assuming that a permit's code-adoption date is the exam transition date. (Minnesota DLI, Electrical codes and standards) | Sept. 28, 2026 |
| Washington | The L&I exam page lists the 2020 edition as the NEC book for the exam. (Washington L&I, Electrical examination) | Sept. 28, 2026 |
What this practice test does about it. The code questions are explicitly labeled by edition: 38 use the 2023 NEC, and Question 50 is a separate 2026 example. The other 11 questions cover electrical theory/calculations or OSHA rules. This is not a complete 2026 update or a substitute for your exam's content outline.
If your exam uses the 2026 NEC, two changes affect how you look things up:
- Load calculations moved. Article 220 became Article 120; for example, 2023 Section 220.41 became 2026 Section 120.41. (EC&M, Changes to Sec. 120.41)
- The dwelling lighting load dropped. It went from 3 to 2 volt-amperes per square foot for service and feeder calculations. The separate 2026 calculation for the minimum number of dwelling branch circuits still uses 3 VA per square foot. (EC&M, 2026 dwelling calculation changes)
Before you choose or tab a codebook, check four things in your bulletin:
- The exact license level. Journeyman, residential, and master exams differ.
- The NEC edition for your test date. Use the exam rule, not the date your state adopted the code for installations.
- What you can bring or will be provided. Check the book format (soft-bound, spiral, loose-leaf), the rules for tabs, highlighting, and notes, and whether other references are allowed.
- The calculator rule, the exam parts, and the time limits.
The Texas bulletin, Minnesota examination guide, and Washington examination page show why those details need to be checked for the specific exam.
To look up a rule without owning the book, NFPA offers free read-only online access to its codes (account required), also described on Minnesota DLI's codes page.
Is the journeyman exam open book, and what score passes?
The three examples below are open book, but their reference rules differ. These are individual state exam requirements, not a national format or a passing standard for this practice set.
For Washington electrician candidates, the one-year examination period starts with exam approval, not the first attempt; the first-attempt rule is for administrator exams. The controlling rule also requires all sections to be retaken in a new examination period if the candidate did not pass them all within the previous period. (WAC 296-46B-960(3))
Sources checked September 28, 2026: PSI Texas electrician bulletin, Journeyman Electrician knowledge and calculations sections; TDLR exam information; Minnesota DLI Electrical License Examination Guide, examination administration and reference materials; Washington L&I examination information; WAC 296-46B-960.
Texas splits the exam into a code portion and a calculations portion, so practice both. Here, calculations are mostly in Electrical theory & calculations, Motors, and a few load and box-fill questions. (TDLR exam information)
Turn a missed question into your next study step
Take the test once with your NEC open and a timer running. For each miss, find the rule in your book before you read our explanation. Use the edition named on the question; the timer is optional practice, not an official time limit. Then match the mistake to a fix:
| What went wrong | What to do next |
|---|---|
| Couldn't find the rule | Note the article you should have opened. If you keep reaching for the same one, tab it (if your bulletin allows tabs). |
| Found the rule, read the wrong row or column | Re-read the stem for the deciding details: copper or aluminum, insulation temperature, number of conductors, dwelling or not. |
| Right method, wrong number | Redo the math with units written out. Check kW vs. W, √3 vs. 3, and one-way vs. round-trip length. |
| Answered a different question than the one asked | Ask which value the stem wants: an operating current, a conductor ampacity, or an overcurrent device rating. Questions 10, 19, and 31 distinguish conductor ampacity, short-circuit/ground-fault protection, and overload protection. |
| Got it right but couldn't explain why | Cover the explanation and work it again tomorrow. |
Example: On Question 11, choosing 65 A means you read the 75 °C column instead of correcting the 90 °C value. That's a "wrong column" miss, not a math miss. The fix is to re-read what insulation the stem gave you.
Sources and independence
By Castleport Test Prep Editorial Team. Last verified: September 28, 2026. On that date we checked the state exam details above, the published code references used for these questions, and the calculation inputs and results. Question 50's 2026 comparison was checked separately; this was not a review of every rule in the 2026 NEC. We could not open the full NEC text in NFPA's interactive reader for this check. The linked agency guidance, published code excerpts, and technical explanations support the answers. This page was prepared with AI assistance under our editorial standards. It has not been reviewed by a licensed electrician.
Official exam sources
- PSI, Texas Department of Licensing and Regulation Electrician Candidate Information Bulletin. Journeyman Electrician knowledge and calculations sections; use TDLR's exam page for the current edition and permitted-book distinction.
- TDLR, Electrician examination information
- Minnesota DLI, Electrical codes and standards
- Minnesota DLI, Electrical License Examination Guide. Examination administration, reference materials, and formula sections.
- Washington L&I, Electrical examination, and WAC 296-46B-960
Code and teaching sources
- NFPA 70, 2023 NEC free-access reader. The reference beside each code question identifies the section to consult.
- Minnesota DLI, Electrical Inspection Checklist for One-Family Dwellings, 2023 NEC. Used for the explicitly labeled 2023 practice questions, not as Minnesota's current exam-edition announcement.
- HELUKABEL, Allowable Ampacity Tables, NFPA 70: NEC–2023
- OSHA 29 CFR 1910.304, 1910.333, and the OSHA GFCI eTool
- The specific code excerpts and technical explanations linked under each question, including Steel Tube Institute guidance, the authorized Leviton 2023 pool-protection excerpt, and EC&M's separately identified 2026 calculation explanation.
Castleport Test Prep is an independent exam prep publisher. We are not affiliated with, endorsed by, or approved by NFPA, PSI, or any state licensing board. These are original practice questions, not actual, recalled, or leaked exam questions. Exam, credential, and code names are used to identify their subjects, and trademarks belong to their respective owners. Practice results don't guarantee passing or licensure. This page is study material, not instructions for doing electrical work.