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Question 1. Which NEC article establishes the purpose, scope, and enforcement authority of the Code? A) Article 100 B) Article 110 C) Article 90 D) Article 210 Answer: C Explanation: Article 90 is the introductory article that states the purpose, objectives, and enforcement procedures of the NEC. Question 2. In NEC terminology, which word indicates a mandatory requirement? A) Should B) May C) Shall D) Could Answer: C Explanation: The NEC uses “shall” exclusively to denote mandatory provisions; “should” is not used. Question 3. What does the NEC definition of “qualified person” require? A) Completion of a high-school electrical course B) Ability to perform the work safely and according to the Code C) Holding a master electrician license only D) Being a licensed electrician in any state Answer: B
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Explanation: A qualified person is anyone who has the skills and knowledge to perform the work safely and in compliance with the Code, regardless of licensure. Question 4. Which color is required to identify a grounded (neutral) conductor in a 120/240 V system? A) Black B) White or gray C) Green D) Red Answer: B Explanation: NEC Article 200 requires grounded conductors to be identified by white or gray insulation, or by marking. Question 5. When may a neutral conductor be re-identified with white tape? A) When it is larger than 4 AWG B) When it is a 6 AWG or larger conductor used as a neutral C) When it is a stranded conductor only D) Never; neutrals must be white from the factory Answer: B Explanation: Conductors 6 AWG or larger can be re-identified with white or gray tape for use as a neutral. Question 6. According to NEC 210.11(C)(1), how many 20-A small-appliance circuits are required in a dwelling unit kitchen? A) One B) Two
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A) 6 ft B) 8 ft C) 10 ft D) 12 ft Answer: C Explanation: Receptacles must be installed so that no point on the floor is more than 6 ft from an outlet, resulting in a maximum spacing of 12 ft between receptacles. Question 10. A lighting load in a dwelling unit is calculated using 3 VA per square foot. A 2,200 ft² house therefore requires a minimum lighting load of: A) 4,400 VA B) 6,600 VA C) 7,200 VA D) 9,600 VA Answer: B Explanation: 2,200 ft² × 3 VA/ft² = 6,600 VA; this is the required minimum lighting load per NEC 220.12. Question 11. Which NEC article governs the sizing of feeder conductors? A) Article 210 B) Article 215 C) Article 230 D) Article 310 Answer: B Explanation: Article 215 provides the rules for feeder sizing, including ampacity, voltage drop, and correction factors.
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Question 12. A feeder supplying a 120/240 V load has a calculated load of 150 A. What is the minimum rating of the overcurrent protective device for this feeder, assuming no demand factors are applied? A) 125 A B) 150 A C) 175 A D) 200 A Answer: B Explanation: The feeder OCPD must be at least equal to the calculated load; therefore a 150-A device is required. Question 13. Which of the following is a permitted feeder tap length for a 4 - wire, 120/240 V feeder with a 100 A OCPD? A) 5 ft B) 25 ft C) 50 ft D) 75 ft Answer: B Explanation: Table 215.2(A)(1) permits a feeder tap of up to 25 ft for a 100-A feeder with a 4-wire configuration. Question 14. NEC 230.70 requires service disconnecting means to be located: A) Within 6 ft of the service entrance point B) At the nearest exterior wall only C) Inside the building or a structure that houses the service equipment D) Anywhere on the premises, regardless of accessibility
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B) Ground rod driven 8 ft into the earth C) Metal water pipe in direct contact with earth for at least 10 ft D) Aluminum siding used as a grounding electrode Answer: D Explanation: Aluminum siding is not listed as an acceptable grounding electrode in NEC 250.52(A). Question 18. What is the minimum size of a grounding electrode conductor (GEC) for a 100-A residential service? A) 14 AWG copper B) 12 AWG copper C) 10 AWG copper D) 8 AWG copper Answer: C Explanation: Table 250.122 specifies a minimum of 10 AWG copper for a 100 - A service. Question 19. When bonding a metal raceway that serves as a grounding conductor, which NEC article applies? A) Article 250. B) Article 300.3(B) C) Article 250. D) Article 310.15(B)(3) Answer: C Explanation: Article 250.134 requires bonding of metal raceways that are used as grounding conductors.
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Question 20. A Surge Protective Device (SPD) installed at the service entrance must be listed under which NEC article? A) Article 280 B) Article 285 C) Article 300 D) Article 250 Answer: B Explanation: Article 285 specifically addresses surge arresters and SPDs, including installation requirements. Question 21. Which conductor insulation type is permitted for use in wet locations? A) THHN only B) THWN-2 only C) NM-B (Romex) only D) UF only Answer: B Explanation: THWN-2 insulation is rated for wet locations, whereas THHN is dry-location only, NM-B is prohibited in wet areas, and UF is a cable type, not an insulation rating. Question 22. What correction factor is applied to ampacity when three current-carrying conductors are bundled in a conduit at 30 °C ambient temperature? A) 0. B) 0. C) 0. D) No correction required
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Question 25. Which NEC article governs the installation of boxes and conduit bodies? A) Article 300 B) Article 314 C) Article 352 D) Article 378 Answer: B Explanation: Article 314 contains the requirements for boxes, conduit bodies, and fittings. Question 26. **For a raceway that is 3 ft in length, what is the maximum number of 90° bends allowed between pull points according to NEC 300.17? ** A) One B) Two C) Three D) No limit as long as the total bend angle does not exceed 360° Answer: B Explanation: NEC 300.17 permits up to two 90° bends (or equivalent) between pull points without a pull box. Question 27. Which type of conduit is permitted for direct burial without additional protection? A) Rigid Metal Conduit (RMC) B) Intermediate Metal Conduit (IMC) C) Electrical Metallic Tubing (EMT) D) Flexible Metal Conduit (FMC) Answer: A
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Explanation: RMC is listed for direct burial (NEC 352.10). IMC and EMT require a raceway or conduit for burial, and FMC is not allowed in direct burial. Question 28. What is the minimum conduit fill percentage for a single conductor in a raceway? A) 20 % B) 30 % C) 40 % D) 50 % Answer: C Explanation: NEC 314.16 requires a minimum of 40 % fill for a single conductor in a conduit. Question 29. Which of the following flexible metal conduits must be listed for use in hazardous (Class I) locations? A) FMC (type C) only B) LFMC only C) Both FMC and LFMC if listed for hazardous locations D) Neither; flexible metal conduit is prohibited in hazardous areas Answer: C Explanation: When listed for hazardous locations, both FMC and LFMC may be used in Class I areas per NEC 376. Question 30. A homeowner wishes to install a 250 V, 30 A dryer circuit using NM-B cable. Is this permitted? A) Yes, NM-B can be used for any dryer circuit B) No, NM-B is prohibited for circuits over 20 A C) Yes, if the cable is rated for 90 °C conductors
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A) Article 300 B) Article 400 C) Article 410 D) Article 422 Answer: B Explanation: Article 400 contains the rules for flexible cords, cables, and their permissible uses. Question 34. A 12-ft length of 18 AWG SJT cord is used to connect a portable lamp. What is the maximum allowable ampacity for this cord? A) 5 A B) 7 A C) 10 A D) 12 A Answer: B Explanation: Table 400.5(C)(1) lists 18 AWG SJT at 7 A maximum. Question 35. Which type of receptacle is required for outdoor installations in wet locations? A) Standard 120 V receptacle B) GFCI-protected receptacle only C) Weather-resistant (WR) receptacle, optionally GFCI-protected D) Two-pole 240 V receptacle only Answer: C Explanation: NEC 406.9(B) requires weather-resistant receptacles in wet locations; GFCI protection may also be required depending on the area.
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Question 36. What is the minimum height above the floor for a receptacle in a kitchen countertop area? A) 12 in. B) 15 in. C) 18 in. D) 24 in. Answer: C Explanation: NEC 210.52(C)(1) specifies receptacles be installed not more than 20 in. above the countertop, with a typical minimum mounting height of 18 in. Question 37. A 30-A, 240 V dryer requires a disconnecting means. Which NEC article addresses the disconnect for appliances? A) Article 210 B) Article 210. C) Article 422 D) Article 430 Answer: C Explanation: Article 422.31 requires a means to disconnect permanently connected appliances. Question 38. Which of the following is NOT a permitted use for a flexible cord according to NEC 400.7? A) Extension of a cord-connected appliance B) As a substitute for fixed wiring in a building C) Temporary connection of a portable tool D) Powering a mobile home appliance Answer: B
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C) Only the equipment grounding conductor (EGC) D) No grounding conductor required for 3-wire feeders Answer: C Explanation: NEC 250.118 requires an equipment grounding conductor when a feeder supplies equipment; the neutral is not a grounding conductor. Question 42. What is the minimum size of a grounding electrode conductor for a 200-A service using copper? A) 6 AWG B) 4 AWG C) 2 AWG D) 1/0 AWG Answer: B Explanation: Table 250.122 lists a minimum of 4 AWG copper for a 200-A service. Question 43. Which type of conduit is required to be threaded when used with a metal raceway system? A) PVC conduit B) EMT C) RMC D) Flexible metal conduit (FMC) Answer: C Explanation: RMC must be threaded at each connection to maintain a continuous metal raceway (NEC 358.12).
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Question 44. **A 90-° bend in a conduit is considered equivalent to how many 45-° bends for the purpose of the “no more than four 90-° bends” rule? ** A) One 90-° bend only B) Two 45-° bends C) Three 45-° bends D) Four 45-° bends Answer: C Explanation: NEC 300.17 treats a 90-° bend as equivalent to three 45-° bends. Question 45. What is the maximum number of 14-AWG NM-B conductors permitted in a 2-in. × 2 - in. cable box (volume 21 cu in.)? A) 8 B) 10 C) 12 D) 14 Answer: C Explanation: Each #14 NM conductor counts as 2.25 cu in. (NEC 314.16). 40 % of 21 = 8.4 cu in.; 8.4 ÷ 2.25 ≈ 3.7, but NEC permits a maximum of 12 #14 conductors in a 2 × 2 box per Table 314.16(A). Therefore answer C. Question 46. Which NEC article addresses the installation of surge protective devices on the service side? A) Article 250 B) Article 285 C) Article 300 D) Article 110
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B) 3
C) 4
D) 5
Answer: B Explanation: NEC 310.15(B)(3)(a) excludes the neutral if it only carries unbalanced current; thus only the three hot conductors count. Question 50. What is the minimum rating for a GFCI protected receptacle in a residential bathroom? A) 15 A, 125 V B) 20 A, 125 V C) 15 A, 250 V D) 20 A, 250 V Answer: A Explanation: NEC 210.8(A)(1) requires 15-A, 125-V GFCI receptacles in bathrooms; a 20-A receptacle is optional but not required. Question 51. Which NEC article governs the installation of armored cable (AC)? A) Article 320 B) Article 334 C) Article 362 D) Article 376 Answer: C Explanation: Article 362 provides the rules for AC cable, including support and protection.
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Question 52. What is the allowable fill for a conduit containing more than two conductors? A) 30 % of the conduit’s internal cross-sectional area B) 40 % of the conduit’s internal cross-sectional area C) 50 % of the conduit’s internal cross-sectional area D) 60 % of the conduit’s internal cross-sectional area Answer: B Explanation: NEC 314.16(B) requires a minimum of 40 % fill for more than two conductors. Question 53. A 15-A circuit supplies a kitchen countertop receptacle. What is the minimum number of receptacles required on this circuit? A) One B) Two C) Three D) Four Answer: B Explanation: NEC 210.52(C)(1) requires at least two receptacles on each countertop circuit. Question 54. Which of the following is the correct designation for a 3-wire, 120/240 V service entrance conductor set? A) Two hots, one neutral, no ground B) Two hots, one neutral, one equipment grounding conductor C) Two hots, two neutrals, one ground D) Three hots, one neutral, no ground Answer: B
