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The NCEC exam has 100 questions and runs 6 hours.
These 10 free NCEC questions are organized by exam domain, so you can see how each part of the North Carolina Electrical Contractor License Exam (Unlimited) blueprint is tested. Reveal the answer and explanation under each question.
A service grounding electrode consists of one listed 8-ft rod. A resistance test measures 37 ohms to earth. Which action satisfies the 2020 NEC rod-electrode rule without another resistance test?
Correct answer: C - Install a supplemental rod at least 6 ft away and bond it to the grounding electrode system
A four-wire feeder supplies a panelboard downstream of the service disconnect. The equipment grounding conductor is intact, but the neutral bar is bonded to the cabinet. What correction addresses the actual defect?
Correct answer: D - Isolate the neutral from the cabinet and keep the equipment grounding path bonded
Conductors with an adjusted ampacity of 92 A supply a single 88-A fixed load. They are not part of a flexible cord or cable assembly, no equipment rule requires a smaller device, and the next standard rating is below 800 A. Select the largest OCPD permitted.
Correct answer: B - 100 A
A switchboard uses a manufacturer-marked series-rated combination of an upstream breaker and a downstream breaker. Available fault current is below the combination rating, and all conditions of the listing are satisfied. The series rating establishes that:
Correct answer: A - The listed combination can interrupt the available fault current
A raceway contains five current-carrying conductors at 30 degrees C. A 3 AWG copper THHN conductor has a 90 degrees C ampacity of 115 A, while the equipment terminals impose a 75 degrees C limit of 100 A. The adjustment factor for four through six current-carrying conductors is 80%. The usable ampacity is:
Correct answer: B - 92 A
PVC raceway is installed underground between two buildings. The raceway was dry when the conductors were pulled, but the conductors are marked THHN only. Which finding is correct?
Correct answer: C - The conductors lack the wet-location identification required inside an underground raceway
An outlet box contains one 12/3 cable and one 12/2 cable. All five insulated 12 AWG conductors enter and are spliced or terminated in the box. The box also contains all 12 AWG equipment grounding conductors and bonding jumpers, one internal cable clamp, one switch yoke connected to 12 AWG conductors, and a 12 AWG pigtail that originates and remains entirely in the box. Using 2.25 cubic inches per 12 AWG allowance and the 2020 NEC counting rules, the box must provide at least:
Correct answer: C - 20.25 cubic inches
At a one-family dwelling, the outdoor emergency disconnect is a meter disconnect installed on the supply side and is not service equipment. The required marking is:
Correct answer: A - EMERGENCY DISCONNECT, METER DISCONNECT, NOT SERVICE EQUIPMENT
Four service designs are proposed. Ignoring specific exceptions such as fire-pump service equipment, which design requires service ground-fault protection of equipment?
Correct answer: D - A 1200-A service disconnect on a 480Y/277-V solidly grounded wye system
A 25-hp, 460-V, three-phase motor has a 28-A nameplate current. The NEC table full-load current is 34 A. For branch-circuit short-circuit and ground-fault protection, a time-delay fuse is permitted at 175% of table FLC, and the next standard rating may be used. The fuse may be rated no more than:
Correct answer: C - 60 A
The NCEC exam also covers these domains. Drill them in the full free practice test:
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