A free NEC Article 406 practice test for the journeyman exam: 14 questions on Receptacles, Cord Connectors, and Attachment Plugs (Caps), each with the answer and the why behind it.
These 14 journeyman-exam practice questions cover NEC Article 406 across 14 code concepts, every one with the correct answer and a plain-English explanation of the rule behind it. They come from the same question bank the Loomi app trains you on — this is the free web sample, not a separate watered-down set.
Work straight down the sheet and answer before you peek: each question hides its answer behind Show answer & explanation. Questions tagged Code lookup are speed drills — race your codebook to the cited section. Printing this page gives you a clean paper worksheet with the answers left off.
TR receptacles are required at 15- and 20-amp, 125- and 250-volt nonlocking outlets in dwellings and a defined list of public and care occupancies, with narrow exceptions for height, appliance-dedicated, and luminaire/appliance receptacles.
Under 406.12, which of the following spaces is explicitly listed as requiring tamper-resistant receptacles?
Correct: C — Dormitory units
406.12(7) lists dormitory units as a required TR location. Restaurant kitchens, rooftop mechanical rooms, and industrial machine shops are not on the enumerated list in 406.12.
No receptacle can sit within 3 ft horizontally of a tub or shower, or within 8 ft vertically above its rim or threshold.
Under 406.9(C), which installation correctly interrupts (limits) the bathtub/shower receptacle keep-out zone?
Correct: A — A full wall separating the receptacle location from the tub/shower space
406.9(C) says the zone is all-encompassing except for space separated by a floor, wall, ceiling, room door, window, or fixed barrier. A full wall qualifies as a separating barrier. A half-wall or open doorway does not fully separate the space, so the zone still applies through them, and distance alone without a qualifying barrier doesn't remove the space from the zone.
Face-up receptacles are banned in countertops, work surfaces, under sinks, and seating areas unless the assembly is specifically listed for that use.
An electrician wants to mount a receptacle face-up directly into a kitchen countertop. Under what condition is this permitted?
Correct: A — Only if the receptacle assembly is listed for countertop applications
Per 406.5(G)(1), a face-up receptacle in a countertop or work surface is prohibited unless the assembly is listed for that countertop or work-surface application. AFCI protection and distance from the sink don't factor into orientation permission; wall-mounting behind the counter is a separate, non-exclusive option.
The grounding pole is green-marked, mates first, and is off-limits for anything but the equipment grounding conductor.
A residential electrician installs a new duplex receptacle where the equipment grounding conductor terminal screw is hidden inside a recessed pressure wire connector, not visible from outside the device. Which section specifies how the conductor entrance hole must be marked in this case?
Correct: A — 406.10(B)
406.10(B) covers grounding-pole identification, including the requirement that when the grounding terminal isn't visible, the conductor entrance hole must be marked with the word green/ground, letters G or GR, a grounding symbol, or a distinctive green color. 406.10(A) only requires the fixed grounding pole itself, not its marking, and 406.10(C)/(D) address terminal use restrictions and connection sequencing, not identification markings.
15- and 20-amp receptacles must be grounding type, and their ground contacts must actually bond to an equipment grounding conductor per 250.146 — not just be present.
An electrician installs a new 20-ampere general-purpose receptacle in a dwelling. Which statement about grounding is correct?
Correct: B — The receptacle must be grounding type, with its EGC contact connected to the circuit's equipment grounding conductor per 250.146
406.4(A) requires grounding-type receptacles on both 15- and 20-ampere branch circuits, and 406.4(B) and (C) require the EGC contacts to actually be connected per 250.146 — a slot alone doesn't satisfy the rule. 406.4(E) clarifies that this doesn't extend to requiring grounded cord-and-plug equipment.
Only CO/ALR-marked receptacles rated 20A or less may connect directly to aluminum conductors; unmarked 15/20A receptacles take copper or copper-clad aluminum only.
An electrician wants to land an aluminum branch-circuit conductor directly on a 20-ampere receptacle. What must the receptacle be marked?
Correct: D — CO/ALR
Per 406.3(C), receptacles rated 20 amperes or less designed for direct connection of aluminum conductors must be marked CO/ALR. There is no exception that waives marking for 20-ampere-or-less receptacles, and 'AL-CU' and 'CC' are not the designations this section uses.
If an equipment grounding conductor is present, install a grounding-type receptacle; if not, you're limited to non-grounding, GFCI-marked, or GFCI-fed grounding-type with proper labels.
An electrician is replacing a worn receptacle in an older home. The outlet box has no equipment grounding conductor and no other grounding means. Which replacement is NOT permitted as described?
Correct: A — A grounding-type receptacle wired with a jumper to the metal box screw, with no verified ground path
406.4(D)(1) only allows a grounding-type receptacle where a grounding means or equipment grounding conductor actually exists and is properly connected — bonding to an ungrounded box without a verified ground path doesn't satisfy this. Where no ground path exists, 406.4(D)(2) permits only a non-grounding replacement, a GFCI marked "No Equipment Ground," or a GFCI-fed grounding-type receptacle with the "GFCI Protected"/"No Equipment Ground" markings.
Swapping a receptacle never lowers its protection — if the outlet needs GFCI, AFCI, tamper-resistant, weather-resistant, control, or GFPE today, the replacement must have it too.
An electrician is replacing a receptacle in a bedroom that falls under the AFCI-required areas of 210.12. The existing receptacle currently has no arc-fault protection. What must the replacement be?
Correct: B — A listed outlet branch-circuit type AFCI receptacle, or a receptacle protected by one, or protected by a listed combination-type AFCI breaker
406.4(D)(4) requires AFCI protection on replacement whenever the outlet is in a 210.12(A)-(C) area, and explicitly states the 210.12(E) Exception does not apply to replacements. GFCI protection addresses ground faults, not arc faults, so it does not substitute for AFCI.
In a wet location, a 15/20 A receptacle's enclosure must stay weatherproof whether the plug is in or out — being covered while unplugged isn't enough.
A 20-ampere, 125-volt receptacle is installed outdoors on a patio where unattended equipment will be plugged in continuously. Per 406.9(B)(1), what must its enclosure do?
Correct: A — Stay weatherproof whether or not the attachment plug cap is inserted
406.9(B)(1) requires that 15 A and 20 A, 125- and 250-volt receptacles in a wet location have an enclosure that is weatherproof whether or not the attachment plug cap is inserted. The weatherproof-only-when-unplugged option is a narrower exception reserved for receptacles subject to routine high-pressure spray washing, not general outdoor use.
Plugs and connectors must have dead-front construction, and prongs can never be energized until plugged into a live source.
Under 406.7(A), which parts of an attachment plug or cord connector are permitted to be exposed current-carrying parts?
Correct: A — Only the prongs, blades, or pins
406.7(A) requires dead-front construction: no exposed current-carrying parts except the prongs, blades, or pins, and the wire-termination cover is essential to the device's operation, not an optional accessory. The other choices describe exposed metal that dead-front construction is meant to prevent.
Outdoor receptacles in protected spots need an enclosure that stays weatherproof with the cap out and the cover closed, and must be listed weather-resistant.
A receptacle is installed under a roofed open porch, shielded from beating rain and runoff. Per 406.9(A), what enclosure condition must it meet?
Correct: B — The enclosure must be weatherproof when covered — plug cap not inserted and cover closed
406.9(A) requires the enclosure to be weatherproof when the receptacle is covered — attachment plug cap not inserted and receptacle covers closed. It's the opposite of the 'weatherproof while in use' misconception, and the location still counts as damp even though it's not exposed to beating rain.
Faceplates must fully cover the opening and seat against the mounting surface; metal ones need minimum thickness and grounding, insulating ones need minimum thickness or reinforcement.
Which requirement applies to ALL metal receptacle faceplates regardless of thickness?
Correct: B — They must be grounded
406.6(B) requires that metal faceplates be grounded, with no exception based on thickness or material type. The noncombustible and reinforcement requirements apply to insulating faceplates under 406.6(C), and 2.54 mm (0.10 in.) is the insulating-material minimum, not a metal faceplate requirement.
Receptacles must sit in securely fastened, identified boxes with the yoke held rigid, and the face must end up flush with or slightly proud of the faceplate.
After installation with a metal faceplate, where must the receptacle face end up per 406.5(D)?
Correct: C — Projecting a minimum of 0.4 mm (0.015 in.) from the metal faceplate
406.5(D) sets a stricter rule for metal faceplates than for insulating ones: the face must project a minimum of 0.4 mm (0.015 in.) from the plate, not merely sit flush. 'Flush, never projecting' and 'recessed' both contradict the minimum projection requirement. The 'flush with or projecting' standard is the rule for insulating faceplates, not metal ones — metal plates need that guaranteed clearance for shock protection.
Single-pole separable connectors must be locking/latching, color-coded white for grounded and green for grounding, and connected/disconnected only in the correct sequence by a qualified person.
Under 406.13(D), which condition allows single-pole separable connectors to be connected and disconnected without sequential-interlocking connectors or a posted caution notice?
Correct: B — The supply connectors are interlocked to the source so connection/disconnection is impossible while energized
406.13(D)(1) permits skipping the sequential-interlocking hardware or caution notice only when the supply connectors are source-interlocked so they physically cannot be mated or separated while energized. Listing, marking, and locking-vs-latching are baseline requirements under 406.13(A), not substitutes for one of the three connect/disconnect safeguards.
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