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Journeyman Electrician Part 2
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Question 1. A dwelling has a 30-A branch circuit feeding a kitchen countertop receptacle outlet. What is the minimum size copper conductor required by the 2023 NEC? A) 10 AWG B) 12 AWG C) 8 AWG D) 14 AWG Answer: A Explanation: For a 30-A circuit, the NEC Table 310.15(B)(16) requires a minimum of 10 AWG copper (rated 30 A). Question 2. A 150-ft run of 12 AWG copper THHN is feeding a 120 V load drawing 20 A. What is the approximate voltage drop? (Use R = 1.93 Ω per 1000 ft). A) 0.58 V B) 0.92 V C) 1.15 V D) 2.30 V Answer: B Explanation: VD = 2 × L × R × I = 2 × 150 ft × (1.93 Ω/1000 ft) × 20 A ≈ 0.92 V. Question 3. When installing conduit with 4 current-carrying conductors in an ambient temperature of 40 °C, which correction factor from NEC Table 310.15(B)(2) (a) applies? A) 0. B) 0. C) 1. D) 1.
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Answer: A Explanation: For 40 °C, the temperature correction factor is 0.94 (NEC Table 310.15(B)(2)(a)). Question 4. A motor rated 5 hp, 460 V, 3-phase, 60 Hz has a full-load current of 7.2 A. What size inverse-time circuit breaker shall be used for protection according to NEC 430.52? A) 10 A B) 15 A C) 20 A D) 30 A Answer: B Explanation: NEC 430.52 requires 125 % of full-load current for inverse-time breakers: 7.2 A × 1.25 = 9 A, rounded up to the next standard size, 10 A. However, the next standard size above 9 A for a motor is 15 A. Question 5. A conduit body is required to accommodate three ½-in. EMT fittings, each with a volume factor of 2.25. What is the minimum conduit body volume in cubic inches? A) 4.5 in³ B) 6.75 in³ C) 9.0 in³ D) 13.5 in³ Answer: B Explanation: Volume = (2.25 × 2) + (2.25 × 2) + (2.25 × 2) = 6.75 in³ (each fitting counts twice). Question 6. Which wiring method is permitted for a wet location outdoors where the conduit is exposed to direct sunlight?
Journeyman Electrician Part 2
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Question 9. A grounding electrode conductor (GEC) is required to be sized based on which NEC table? A) Table 250. B) Table 310.15(B)(16) C) Table 220. D) Table 310. Answer: A Explanation: NEC Table 250.122 provides the minimum size of the GEC based on the rating of the service or feeder. Question 10. A transformer has a primary voltage of 480 V, a secondary voltage of 120 V, and a rating of 30 kVA. What is the full-load secondary current? A) 250 A B) 125 A C) 200 A D) 300 A Answer: B Explanation: I = kVA / V = 30 kVA / 120 V = 250 A. However, the NEC uses a 125 % factor for overcurrent protection; the base current is 250 A, but the standard answer requested is 250 A. Since 250 A is not listed, the nearest correct calculation is 250 A, indicating a mis-print. The correct answer should be 250 A; however, given the options, 125 A (half) is incorrect. The correct answer is A) 250 A. Question 11. The NEC requires that a box used for a 3-wire (hot-hot-neutral) branch circuit serving a receptacle must have a minimum volume of how many cubic inches per conductor? A) 2.0 in³ B) 2.5 in³
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C) 3.0 in³ D) 4.0 in³ Answer: B Explanation: NEC Table 314.16(A) specifies 2.5 in³ per insulated conductor for a non-grounding conductor. Question 12. Which of the following is the correct method for grounding a metal conduit that serves as the equipment grounding conductor? A) Use a separate copper grounding wire. B) Connect the conduit to the grounding bar at each enclosure. C) No grounding is needed if the conduit is continuous. D) Only ground at the service equipment. Answer: B Explanation: The metal conduit must be bonded to the equipment grounding conductor at each enclosure to maintain a low-impedance path. Question 13. A 20-amp GFCI breaker protects a bathroom receptacle circuit. What is the maximum number of receptacles allowed on this circuit per NEC 210.11(C)(3)? A) 6 B) 8 C) No limit, provided load does not exceed 180 VA. D) 12 Answer: C Explanation: NEC does not limit the number of receptacles; the circuit must not exceed 180 VA per receptacle, and the total load must stay within the 20-A rating.
Journeyman Electrician Part 2
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Answer: A Explanation: Article 700 covers emergency systems, including emergency lighting. Question 17. A 120-V, 15-A receptacle is required to be GFCI protected in a garage. Which of the following meets the code requirement? A) A GFCI receptacle installed at the outlet. B) A 20-A GFCI breaker protecting the entire circuit. C) Both A and B are acceptable. D) Neither A nor B; a 30-A GFCI breaker is required. Answer: C Explanation: Either a GFCI receptacle at the point of use or a GFCI breaker protecting the circuit satisfies the requirement. Question 18. When calculating conduit fill for three 4-AWG THHN conductors, what is the allowable fill percentage for a conduit larger than 1 in? A) 15 % B) 25 % C) 30 % D) 40 % Answer: B Explanation: NEC 348.12 permits a maximum of 25 % fill for more than two conductors in conduit larger than 1 in. Question 19. A motor controller must be installed within how many feet of the motor according to NEC 430.102? A) 10 ft B) 25 ft
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C) 50 ft D) No distance limitation Answer: B Explanation: NEC requires the disconnecting means to be within sight and not more than 25 ft from the motor. Question 20. For a 3-phase, 4-wire feeder supplying a panelboard, what is the minimum size of the equipment grounding conductor if the feeder is 60 A copper? A) 14 AWG B) 12 AWG C) 10 AWG D) 8 AWG Answer: B Explanation: Table 250.122 indicates a 60-A feeder requires a minimum of 12 AWG copper for the EGC. Question 21. In a commercial building, how many AFCI breakers are required for a 30-A branch circuit feeding a bedroom? A) One AFCI breaker at the panel. B) Two AFCI breakers, one at the panel and one at the first receptacle. C) No AFCI required; GFCI only. D) AFCI required only for circuits over 50 A. Answer: A Explanation: NEC 210.12 requires AFCI protection for bedroom circuits; a single AFCI breaker at the panel satisfies the requirement.
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Answer: A Explanation: The NEC standard symbol for a fire-pump disconnect is a circle labeled “DP” (Disconnect Pump). Question 25. In Massachusetts, the required minimum clearance between the top of a recessed luminaire and the ceiling in a wet location is: A) 3 in B) 6 in C) 9 in D) No clearance required if rated for wet locations Answer: B Explanation: MA amendment requires a minimum 6-inch clearance for wet-location recessed luminaires to prevent moisture accumulation. Question 26. A 12-kVA, 240-V single-phase transformer has a primary fuse rating of: A) 30 A B) 45 A C) 60 A D) 75 A Answer: B Explanation: Primary current = kVA / V = 12 kVA / 240 V = 50 A. The next standard fuse size above 125 % (62.5 A) is 75 A, but NEC Table 450.3(A) allows a 45 A fuse for 12 kVA at 240 V. Question 27. Which NEC article addresses the use of MC cable in exposed indoor locations? A) Article 320
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B) Article 330 C) Article 340 D) Article 352 Answer: C Explanation: Article 340 governs the installation of MC (Metal-Clad) cable, including exposed indoor use. Question 28. A licensed journeyman electrician must display his license in the workplace. According to MGL c. 141, where must the license be displayed? A) On the electrician’s personal tool belt. B) At the main service entrance. C) In a conspicuous location at the job site office or on the vehicle. D) Only when requested by an inspector. Answer: C Explanation: Massachusetts law requires the license to be displayed conspicuously at the job site, typically on the site office or vehicle. Question 29. An emergency system must be supplied from an independent source. Which NEC article defines “independent source”? A) Article 700. B) Article 250. C) Article 110. D) Article 240. Answer: A Explanation: NEC 700.12 defines “independent source” for emergency systems.
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Answer: A Explanation: Massachusetts requires all receptacles in finished basements to be GFCI protected. Question 33. A 4-wire feeder supplies a 120/240-V panelboard. The feeder is 100 A copper. What is the minimum size of the grounding electrode conductor (GEC) to the earth ground? A) 6 AWG B) 8 AWG C) 10 AWG D) 12 AWG Answer: B Explanation: Table 250.122 indicates a 100-A service requires a minimum 8 AWG copper GEC. Question 34. When a conduit is used as the equipment grounding conductor, what is the minimum size of the conduit required for a 60-A circuit? A) ½ in. EMT B) ¾ in. EMT C) 1 in. EMT D) 1¼ in. EMT Answer: B Explanation: For a 60-A circuit, Table 250.122 requires a 10 AWG copper EGC. A ¾-in. EMT has an internal diameter sufficient to serve as a 10 AWG equivalent. Question 35. A fire alarm system must be supplied from a dedicated circuit. According to NEC, what is the maximum ampacity of that circuit?
Journeyman Electrician Part 2
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A) 15 A
B) 20 A
C) 30 A
D) No maximum; depends on load. Answer: D Explanation: NEC 760.41 requires a dedicated circuit but does not set a universal ampacity limit; it must be sized for the specific fire alarm load. Question 36. Which of the following is NOT a permissible method for grounding a metal conduit that runs outdoors? A) Using a grounding clamp at each enclosure. B) Running a separate copper grounding wire alongside the conduit. C) Relying on the conduit’s continuity without clamps. D) Bonding the conduit to the grounding electrode system at the service. Answer: C Explanation: Continuity alone is insufficient; proper bonding devices must be used at each termination. Question 37. A 3-phase motor has a service factor of 1.15 and a rated full-load current of 20 A. What is the maximum overload protection setting for an inverse-time circuit breaker? A) 115 % B) 125 % C) 150 % D) 175 % Answer: B
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D) Article 358 Answer: A Explanation: Article 330 covers Metal-Clad (MC) cable, including provisions for wet locations. Question 41. A 250-V, 30-A feeder supplies a subpanel. What is the minimum size of the equipment grounding conductor for this feeder? A) 12 AWG copper B) 10 AWG copper C) 8 AWG copper D) 6 AWG copper Answer: B Explanation: Table 250.122 indicates a 30-A circuit requires at least 10 AWG copper for the EGC. Question 42. According to NEC, what is the maximum number of conductors allowed in a ½-in. EMT conduit without exceeding the 40 % fill rule? A) 3 B) 4 C) 5 D) 6 Answer: B Explanation: A ½-in. EMT has an internal area of 0.304 in²; 40 % = 0.122 in². Using 12 - AWG THHN (0.0133 in²), a maximum of 9 conductors could fit, but the NEC limits to 4 for ease of pulling.
Journeyman Electrician Part 2
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Question 43. In a commercial fire alarm system, the Class C circuits are required to be protected by: A) Fuses only. B) Circuit breakers only. C) Either fuses or circuit breakers, rated not less than 125 % of the load. D) No overcurrent protection is required. Answer: C Explanation: NEC 760.41 allows fuses or breakers sized at least 125 % of the load for Class C fire alarm circuits. Question 44. A 120-V receptacle is required to be installed in a bathroom. Which combination of protection is required by the NEC? A) GFCI only. B) AFCI only. C) Both GFCI and AFCI. D) Neither; standard receptacle is acceptable. Answer: A Explanation: NEC 210.8(A)(1) mandates GFCI protection for bathroom receptacles. AFCI is not required. Question 45. According to 527 CMR 12.00, what is the required minimum height for a receptacle outlet installed in a residential kitchen countertop? A) 12 in. above the countertop. B) 15 in. above the countertop. C) 18 in. above the countertop. D) No minimum height; must be no more than 48 in. above the floor. Answer: D
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C) Hanging from joists at intervals not exceeding 4 ft. D) No support required if the cable is less than 6 ft long. Answer: C Explanation: NEC 334.30 permits NM cable to be supported at intervals not exceeding 4 ft when run through bored holes, but when run across joists it must be supported at intervals not exceeding 4 ft. Hanging from joists is acceptable if the spacing does not exceed 4 ft. Question 49. A 3-phase, 4-wire feeder supplies a 480-V motor. The feeder is sized at 250 kCM. What is the appropriate size of the overcurrent protective device for the feeder? A) 250 A B) 300 A C) 350 A D) 400 A Answer: B Explanation: NEC 310.15(B)(16) indicates 250 kCM copper at 75 °C is rated for 260 A; the next standard breaker size is 300 A. Question 50. In a commercial building, a fire pump must be supplied from an independent source. Which NEC article defines “independent source”? A) Article 700. B) Article 250. C) Article 110. D) Article 240. Answer: A Explanation: NEC 700.12 provides the definition of “independent source” for emergency systems, including fire pumps.
Journeyman Electrician Part 2
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Question 51. A 120-V receptacle is installed in a garage that also contains a 240 - V EV charger. What GFCI protection is required for the 120-V receptacle? A) No GFCI required because the garage already has a 240-V charger. B) GFCI protection at the receptacle only. C) GFCI protection at the panel for the entire garage circuit. D) Both B and C are acceptable. Answer: D Explanation: NEC allows GFCI protection either at the receptacle or at the circuit breaker; both methods satisfy the requirement. Question 52. According to Massachusetts amendments, what is the minimum height for a smoke detector installed in a hallway? A) 4 ft. above the floor. B) 6 ft. above the floor. C) 8 ft. above the floor. D) No specific height; must be on the ceiling or high on a wall. Answer: D Explanation: MA follows NEC 710.8, which requires smoke detectors to be mounted on the ceiling or high on a wall, not specifying a minimum height. Question 53. A 3-phase motor has a locked-rotor current (LRC) of 60 A. What is the maximum rating of the short-circuit protective device (SCPD) allowed by NEC 430.32? A) 100 % of LRC B) 115 % of LRC C) 150 % of LRC D) 200 % of LRC
