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Journeyman Electrician
Ultimate Exam
Question 1. Which equation correctly expresses electrical power in terms of voltage and current? A) P = V ÷ I B) P = I × V C) P = V – I D) P = I² ÷ V Answer: B Explanation: Power (P) equals voltage (V) multiplied by current (I); the formula is P = V × I. Question 2. According to NEC Article 100, which term describes a component that can be reached without using tools or removing obstacles? A) Accessible B) Readily Accessible C) Serviceable D) Visible Answer: B Explanation: “Readily Accessible” means capable of being reached quickly without the use of tools or removing obstacles. Question 3. In OSHA safety standards, which PPE is required when working on energized conductors above 50 V? A) Hard hat only B) Safety glasses only C) Insulated gloves and protective clothing D) Steel-toe boots only Answer: C Explanation: Insulated gloves and appropriate protective clothing are required for work on energized parts above 50 V to prevent shock.
Journeyman Electrician
Ultimate Exam
Question 4. A 120/240-V, 200-A service has a calculated load of 140 kVA. What is the minimum size of the main breaker required? A) 125 A B) 150 A C) 200 A D) 250 A Answer: C Explanation: The service rating (200 A) must be at least equal to the calculated load; the main breaker must be sized to the service rating, 200 A. Question 5. Which conductor size is the minimum allowable for a 100-A feeder using THHN insulation in a 75 °C column? A) #2 AWG copper B) #4 AWG aluminum C) #3 AWG copper D) #6 AWG copper Answer: C Explanation: In the 75 °C column, #3 AWG copper THHN is rated for 100 A. #2 AWG is larger than required; #6 AWG is insufficient. Question 6. When installing an underground service-entrance conductor, the minimum cover depth for PVC conduit in residential soil is: A) 12 in. B) 18 in. C) 24 in. D) 30 in. Answer: B
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Answer: B Explanation: NEC 210.20(A) requires a rating of at least 125 % of the continuous load. Question 10. Which NEC article defines the requirements for grounding electrode conductors? A) 250 B) 300 C) 310 D) 430 Answer: A Explanation: Article 250 covers grounding and bonding, including grounding electrode conductors. Question 11. What is the minimum size of a grounding electrode conductor (GEC) for a 100-A service using copper? A) #12 AWG B) #10 AWG C) #8 AWG D) #6 AWG Answer: B Explanation: NEC 250.66 Table 250.66 specifies #10 AWG copper for a 100-A service. Question 12. A metal water pipe used as a grounding electrode must be bonded within how many feet of the service disconnect? A) 5 ft B) 10 ft C) 12 ft
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D) 18 ft Answer: B Explanation: NEC 250.104(A)(1) requires bonding to the metal water pipe within 5 ft of the point where the pipe enters the building, but the grounding electrode conductor must be within 10 ft of the service disconnect. Question 13. Which of the following is the correct box-fill calculation for a single-gang metal box housing one switch, one grounding conductor, and one equipment grounding conductor? (Assume 14 AWG conductors) A) 1 × 2 cu in. B) 2 × 2 cu in. C) 3 × 2 cu in. D) 4 × 2 cu in. Answer: B Explanation: Each ungrounded or neutral conductor counts as one volume unit (2 cu in. for 14 AWG). All equipment grounding conductors together count as one unit. Thus, 1 (switch) + 1 (ground) = 2 × 2 cu in. Question 14. When installing NM-B (Romex) cable in a wall cavity, the maximum spacing between staples is: A) 4 in. B) 6 in. C) 8 in. D) 12 in. Answer: C Explanation: NEC 334.30 requires NM cable to be secured within 8 in. of a box and at intervals not exceeding 4 ft; however, for non-metallic sheathed cable, the maximum spacing between staples is 8 in. Question 15. A 20-A GFCI receptacle is installed in a bathroom. Which of the following statements is correct?
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A) A metal underground water pipe B) A concrete-encased electrode (Ufer) C) A metal roof fastener D) A grounding rod of any length Answer: B Explanation: NEC 250.52(A)(3) mandates a concrete-encased electrode (Ufer) as an acceptable grounding electrode for new construction. Question 19. When calculating voltage drop for a 500-ft run of 3-phase, 120/208-V conductors feeding a 30-A load, the maximum allowable voltage drop is: A) 2 % per conductor B) 3 % total for the circuit C) 5 % per phase D) 10 % total Answer: B Explanation: NEC recommends a maximum of 3 % voltage drop for the entire branch circuit. Question 20. Which of the following wiring methods is permitted for an exposed ceiling in a commercial office space? A) NM-B cable without a raceway B) MC cable with metal armor C) AC cable without support D) UF cable buried in the ceiling cavity Answer: B Explanation: MC cable is allowed in exposed ceilings; NM-B is prohibited in exposed work areas.
Journeyman Electrician
Ultimate Exam
Question 21. According to NEC 210.52(A)(1), the minimum number of receptacles required in a dwelling unit kitchen countertop space of 12 ft is: A) 2 B) 3 C) 4 D) 6 Answer: C Explanation: NEC requires one receptacle outlet for each 12 in. of countertop space, minimum of two; a 12-ft countertop (144 in.) requires at least 12 receptacles, but the code sets a minimum of four in a kitchen. Question 22. Which of the following is the correct method to size an equipment grounding conductor for a 30-A circuit using copper? A) #12 AWG B) #10 AWG C) #8 AWG D) #6 AWG Answer: B Explanation: NEC Table 250.122 indicates #10 AWG copper for a 30-A overcurrent device. Question 23. A 3-wire cable (black, white, green) is used for a 240-V, single-phase circuit feeding a water heater. Which conductor serves as the equipment grounding conductor? A) Black B) White C) Green D) None – a separate grounding wire is required Answer: C
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Answer: C Explanation: NEC 250.68(A) requires a minimum of #8 AWG copper for pools and spas. Question 27. Which NEC article governs the installation of fire alarm circuits? A) 300 B) 700 C) 800 D) 210 Answer: B Explanation: Article 700 covers emergency systems, including fire alarm circuits. Question 28. A 15-A, 120-V receptacle is required to be GFCI-protected in which of the following locations? A) Living room B) Kitchen countertop C) Bedroom D) Hallway Answer: B Explanation: NEC 210.8(A)(2) mandates GFCI protection for receptacles serving kitchen countertops. Question 29. When sizing a feeder for a lighting load of 10 kW at 277 V, what is the calculated current? A) 25 A B) 30 A C) 35 A D) 40 A Answer: B
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Explanation: Current = Power / Voltage = 10,000 W / 277 V ≈ 36 A. However, using NEC rounding and demand factors, the nearest standard feeder size is 30 A. Question 30. Which of the following is the correct minimum burial depth for a direct-buried single-conductor copper grounding electrode in residential soil? A) 4 in. B) 6 in. C) 8 in. D) 12 in. Answer: D Explanation: NEC 250.52(A)(5) requires a minimum of 8 ft for a grounding rod; however, a direct-buried conductor must be at least 12 in. deep. Question 31. An AFCI breaker is required in which of the following residential circuits? A) Dedicated 20-A circuit for a refrigerator B) General-purpose 15-A circuit serving bedroom outlets C) 30-A circuit for a garage door opener D) 20-A circuit for a bathroom vanity light Answer: B Explanation: NEC 210.12(A) requires AFCI protection for all 120-V, 15- and 20-A branch circuits supplying outlets in bedrooms. Question 32. Which of the following is the correct method to terminate a grounding electrode conductor to a concrete-encased electrode? A) Clamp directly to rebar B) Tie with a knot C) Use a listed exothermic weld D) Connect to the water pipe only
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Answer: B Explanation: In the 75 °C column, #6 AWG copper THHN is rated for 65 A, sufficient for a 60-A feeder. Question 36. Which NEC article addresses the requirements for low-voltage fire alarm circuits? A) 300 B) 500 C) 700 D) 800 Answer: C Explanation: Article 700 covers fire alarm and detection systems, including low-voltage circuits. Question 37. A conduit fill calculation for a 3/4-in. EMT with three #12 AWG THHN conductors results in a fill percentage of: A) 10 % B) 20 % C) 30 % D) 40 % Answer: B Explanation: The allowable fill for three conductors in a conduit is 40 % of the internal area; three #12 AWG THHN occupy roughly 20 % of a 3/4-in. EMT. Question 38. Which of the following devices must be GFCI-protected when installed outdoors in a residential setting? A) A 120-V receptacle for a ceiling fan B) A 240-V receptacle for an electric dryer C) A 120-V receptacle for a garden tool
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D) A 120-V receptacle for a TV antenna Answer: C Explanation: NEC 210.8(A)(3) requires outdoor receptacles to be GFCI-protected. Question 39. The minimum size of a copper grounding electrode conductor for a 400 - A service is: A) #4 AWG B) #2 AWG C) #1/0 AWG D) #4/0 AWG Answer: C Explanation: Table 250.122 specifies #1/0 AWG copper for a 400-A overcurrent device. Question 40. Which wiring method is permitted for a Class II, Division 1 hazardous area? A) NM-B cable B) Rigid metal conduit with THHN C) PVC conduit with UF cable D) Flexible metal conduit with AC cable Answer: B Explanation: Rigid metal conduit with THHN conductors is acceptable in Class II, Division 1 locations. Question 41. When installing a receptacle in a bathroom, the required spacing from the edge of the bathtub or shower stall is: A) 12 in. B) 18 in. C) 24 in.
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A) Using a listed bonding jumper no longer than 6 ft B) Wrapping the pipe with copper tape C) Connecting a grounding electrode conductor with a listed clamp within 5 ft of the service entrance D) No bonding required if the pipe is underground Answer: C Explanation: NEC 250.104(A)(1) requires bonding the water pipe within 5 ft of where it enters the building using a listed clamp. Question 45. Which of the following is the required minimum size of a copper grounding electrode conductor for a 150-A feeder? A) #10 AWG B) #8 AWG C) #6 AWG D) #4 AWG Answer: C Explanation: Table 250.122 indicates #6 AWG copper for a 150-A overcurrent device. Question 46. A 240-V, 30-A receptacle must be installed in a garage to serve a EV charger. Which device is required? A) Standard 30-A two-pole breaker B) 30-A GFCI breaker C) 30-A AFCI breaker D) 30-A dual-function GFCI/AFCI breaker Answer: B Explanation: NEC 210.8(A)(2) requires GFCI protection for 125-V, single-phase, 15- and 20-A receptacles in garages; for 240-V, 30-A receptacles, a GFCI breaker is required.
Journeyman Electrician
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Question 47. Which of the following is the correct maximum distance between supports for a horizontal run of 1-in. EMT conduit? A) 4 ft B) 6 ft C) 8 ft D) 10 ft Answer: C Explanation: NEC 358.30 requires EMT to be supported at intervals not exceeding 10 ft, but horizontal runs must have a support within 3 ft of each outlet box; the maximum spacing between intermediate supports is 8 ft. Question 48. In a data center, which class of low-voltage circuit is used for voice communication? A) Class 1 B) Class 2 C) Class 3 D) Class 4 Answer: B Explanation: NEC Chapter 8 defines Class 2 circuits as limited-power circuits for voice, data, and similar communications. Question 49. A 120-V, 15-A lighting circuit supplies 12 recessed lights. What is the total load in VA? A) 1,800 VA B) 2,100 VA C) 2,400 VA D) 3,000 VA Answer: B
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C) #8 AWG copper D) #6 AWG copper Answer: C Explanation: NEC 250.66 requires at least #8 AWG copper for a concrete-encased electrode of 6 in. diameter. Question 53. In a commercial kitchen, which type of receptacle is required for a dishwasher? A) 15-A, 125-V B) 20-A, 125-V C) 20-A, 250-V D) 30-A, 250-V Answer: C Explanation: Dishwashers are typically 20-A, 240-V (two-pole) receptacles per NEC 210.23(A)(2). Question 54. Which NEC article governs the installation of underground direct-buried conductors? A) 250 B) 300 C) 310 D) 225 Answer: B Explanation: Article 300 covers wiring methods, including underground direct-buried conductors. Question 55. A 120-V, 15-A lighting circuit is required to have a dedicated branch circuit in a hallway. This is mandated by which NEC provision? A) 210.11(C)(1)
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B) 210.12(A)
C) 210.23(A)(1)
D) 210.52(B)
Answer: C Explanation: NEC 210.23(A)(1) requires a dedicated 20-A circuit for lighting in hallways when the load exceeds 180 VA. Question 56. Which of the following is the correct minimum size of a copper grounding electrode conductor for a 100-kVA, 208-V service? A) #6 AWG B) #4 AWG C) #2 AWG D) #1/0 AWG Answer: B Explanation: The overcurrent device for 100 kVA at 208 V is about 300 A; Table 250.122 calls for #4 AWG copper for 300 A. Question 57. For a 3-phase, 480-V motor rated 10 hp, which type of overcurrent protection is required by NEC? A) Inverse-time circuit breaker only B) Fuse only C) Either an inverse-time breaker or a time-delay fuse, sized per Table 430. D) No overcurrent protection needed for motors Answer: C Explanation: NEC 430.32 allows either an inverse-time breaker or a time-delay fuse sized according to Table 430.52. Question 58. Which of the following is the correct maximum number of conductors allowed in a 1-in. EMT conduit without exceeding the 40 % fill limit?
