NECPracticeTest

Free NEC practice questions,
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Exam-style questions for journeyman electrician prep, aligned to the 2023 National Electrical Code®. Every question below is cross-verified against the code text by working electricians, with the article reference to prove it.

Try ten. See where you stand.

Question 1 · Branch Circuits & Feeders · moderate
NEC 2023 · General practice — jurisdiction-specific amendments not evaluated.

A branch circuit supplies 20 A continuously and 8 A noncontinuously. The 100%-rated-assembly exception does not apply. Using the ordinary 210.20(A) load rule, and assuming all other equipment and conductor-protection requirements allow the selection, what is the minimum standard OCPD rating in Table 240.6(A)?

NEC 2023 210.20(A) and Table 240.6(A) — The required load-based rating is 8 + (20 x 1.25) = 33 A. The smallest listed standard rating at or above that value is 35 A. The 28 A choice omits the continuous-load factor; 30 A is below the required 33 A. Dropping the 8 A load would produce 25 A, so it does not explain the 30 A distractor.
Question 2 · Equipment for General Use · moderate
NEC 2023 · General practice — jurisdiction-specific amendments not evaluated.

An electrician runs a stairwell light controlled from top and bottom using three-way switches. To comply with the Code, the switching contacts must make and break which conductor of the circuit?

NEC 2023 404.2(A) — 404.2(A) requires that switching for three-way and four-way switches be arranged so that all switching is done only in the ungrounded circuit conductor.
Question 3 · General Theory & Definitions · moderate
NEC 2023 · General practice — jurisdiction-specific amendments not evaluated.

A panelboard operating at 120 volts to ground is mounted on a concrete wall with no live or grounded parts on the opposite side of the working space (Condition 1). What minimum depth of clear working space is required in front of it?

NEC 2023 Table 110.26(A)(1) — Per Table 110.26(A)(1), for equipment at 0-150 volts to ground the working-space depth is 3 ft (900 mm) for all three conditions. The 3 1/2 ft and 4 ft values apply to higher voltage ranges; 30 in. is the required width, not depth.
Question 4 · Grounding & Bonding · moderate
NEC 2023 · General practice — jurisdiction-specific amendments not evaluated.

A 400 A service has a single made ground rod as its only grounding electrode. That rod is the sole connection to earth. What is the largest copper GEC size the Code requires you to run to that rod?

NEC 2023 250.66(A) — Where the GEC connects only to a rod, pipe, or plate electrode, that portion is not required to be larger than 6 AWG copper, regardless of what Table 250.66 would otherwise require for a 400 A service. Missing this allowance leads to oversizing per the base table.
Question 5 · Overcurrent Protection · moderate
NEC 2023 · General practice — jurisdiction-specific amendments not evaluated.

A feeder is made up of conductors with an allowable ampacity of 115 A. The circuit does not supply receptacles for cord-and-plug portable loads, and 115 A is not a standard device rating. Applying the next-higher-standard allowance, what is the largest overcurrent device permitted?

NEC 2023 240.4(B) — Because 115 A falls between the standard ratings 110 and 125 and the 240.4(B) conditions are met, the next higher standard rating, 125 A, may be used.
Question 6 · Services · moderate
NEC 2023 · General practice — jurisdiction-specific amendments not evaluated.

For one service using the multiple-disconnect arrangement permitted by 230.71(B), what is the maximum number of service disconnecting means in that arrangement?

NEC 2023 230.71, particularly 230.71(B) — The permitted multiple-disconnect arrangement has a maximum of six. It must meet the equipment arrangements in 230.71(B); a separate enclosure for each disconnect is one permitted arrangement, rather than a description of every permitted arrangement. The parent rule generally calls for one disconnect unless (B) applies.
Question 7 · Special Equipment & Conditions · moderate
NEC 2023 · General practice — jurisdiction-specific amendments not evaluated.

A permanently installed pool at a dwelling unit requires at least one 125-volt, 15- or 20-ampere general-purpose receptacle. Measured from the inside wall of the pool, within what distance range must this required receptacle be located?

NEC 2023 680.22(A)(1) — 680.22(A)(1) requires at least one 125V, 15/20A general-purpose receptacle located not less than 6 ft and not more than 20 ft from the inside wall of the pool. The other ranges alter one or both bounds.
Question 8 · Special Occupancies · moderate
NEC 2023 · General practice — jurisdiction-specific amendments not evaluated.

In a major repair garage for gasoline-fueled vehicles, repairs include draining gasoline from vehicle fuel tanks. The floor area lacks the ventilation that would allow it to be unclassified under Table 511.3(C). Considering the general floor area rather than a pit or an additional dispensing-location classification, how high does its Class I, Division 2 zone extend above the floor?

NEC 2023 511.3(C) and Table 511.3(C) — For this major-repair gasoline case, the applicable floor zone extends 18 in. above the floor. The specified activity and ventilation conditions matter. This answer does not classify pits, dispensing locations or garages using lighter-than-air fuels.
Question 9 · Wiring Methods & Materials · moderate
NEC 2023 · General practice — jurisdiction-specific amendments not evaluated.

Six current-carrying conductors are installed in a single raceway for more than 24 in. What adjustment factor must be applied to their allowable ampacity per Table 310.15(C)(1)?

NEC 2023 Table 310.15(C)(1) — Table 310.15(C)(1): 4-6 current-carrying conductors require an 80% adjustment. 70% applies to 7-9 conductors and 50% to 10-20.
Question 10 · Wiring Methods & Materials · difficult
NEC 2023 · General practice — jurisdiction-specific amendments not evaluated.

Where a cabinet or cutout box is used as a raceway (conductors feeding through with splices and taps), the conductors plus all splices and taps together must not fill more than what percentage of the cross-sectional area at that point?

NEC 2023 312.8(A) — 312.8(A): conductors, splices, and taps within a cabinet or cutout box used as a raceway must not exceed 75% of the cross-sectional area of the space, while the conductors alone must not exceed 40%. The 40% distractor is the conductors-only limit.

Study guides

How to Study for the Journeyman Exam

The nine topic areas the exam draws from, and why code navigation beats memorization.

Grounding & Bonding: The Rules Everyone Mixes Up

Ground rods, the 25-ohm rule, and the GEC sizing allowance that trips up oversizers.

Overcurrent Protection: The Rules the Exam Loves

Small-conductor caps, the next-size-up allowance, and the 125% continuous-load factor.

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