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Journeyman Electricians Certification Review Guide
[NENJE]
Question 1. When reading a one‑line diagram, which symbol represents a main service disconnect? A) Circle with a “P” inside B) Square with the letters “SD” C) Rectangle with a diagonal line D) Circle with a slash through it Answer: B Explanation: NEC designates the main service disconnect with a square labeled “SD” (Service Disconnect) on one‑line drawings. Question 2. A blueprint shows a conduit run at a scale of 1” = 10 ft. If the drawing measures 3½ inches, what is the actual length of the conduit? A) 20 ft B) 30 ft C) 35 ft D) 45 ft Answer: C Explanation: Multiply the drawing length (3.5 in) by the scale factor (10 ft/in) → 35 ft. Question 3. Which PPE item is required for protection against an arc‑flash incident rated at 35 cal/cm²? A) Hard hat only B) Arc‑rated face shield and flame‑resistant clothing C) Safety glasses and insulated gloves D) Ear protection and steel‑toed boots
Journeyman Electricians Certification Review Guide
[NENJE]
Answer: B Explanation: Arc‑rated clothing and face protection are mandatory for flash hazards ≥ 1.2 cal/cm²; a 35 cal/cm² rating demands the highest level of arc‑rated PPE. Question 4. Under OSHA 1910.147, which of the following is the first step in a Lockout/Tagout (LOTO) procedure? A) Verify that the energy source is isolated. B) Apply the lock and tag. C) Notify affected employees. D) Shut down the equipment. Answer: D Explanation: The procedure begins with shutting down the equipment before isolating the energy source. Question 5. According to NFPA 70E, what does the term “readily accessible” mean? A) Can be reached without using tools or removing obstacles. B) Must be within 6 ft of the work area. C) Requires a ladder to reach. D) Must be labeled with a warning sign. Answer: A Explanation: “Readily accessible” indicates that the equipment can be reached quickly without tools or moving objects. Question 6. Ohm’s Law states that V = I × R. If a motor draws 12 A at 240 V, what is its resistance? A) 10 Ω
Journeyman Electricians Certification Review Guide
[NENJE]
Question 9. When testing a three‑phase motor with a megohmmeter, what is the primary purpose of the test? A) Measure winding resistance. B) Verify insulation integrity. C) Determine motor speed. D) Check phase rotation. Answer: B Explanation: A megohmmeter (megger) tests insulation resistance to detect breakdowns. Question 10. A conduit fill calculation for EMT must not exceed what percentage of the conduit’s internal cross‑section for more than two conductors? A) 20 % B) 30 % C) 40 % D) 53 % Answer: D Explanation: NEC Table 1 allows up to 53 % fill for three or more conductors in EMT. Question 11. Which NEC article defines the requirements for grounding and bonding of electrical systems? A) Article 210 B) Article 250 C) Article 300 D) Article 430 Answer: B
Journeyman Electricians Certification Review Guide
[NENJE]
Explanation: Article 250 covers grounding and bonding rules. Question 12. In a hazardous (Class I) location, which type of conduit is permitted for wiring? A) PVC conduit only B) Rigid metal conduit (RMC) only C) Both PVC and RMC, provided they are listed for the area D) Flexible metal conduit (FMC) only Answer: C Explanation: Both PVC and RMC are acceptable if they have the proper listing for the specific Class I division. Question 13. A building plan calls for a “dedicated 120/240 V, 100 A service entrance.” Which conductor size (copper, THHN) is the minimum required for the service‑entrance conductors? A) 2 AWG B) 4 AWG C) 6 AWG D) 8 AWG Answer: B Explanation: NEC Table 310.15(B)(16) shows 4 AWG copper THHN rated for 100 A at 75 °C. Question 14. Which of the following is the correct method to verify that a circuit is de‑energized before starting work? A) Rely on the lockout tag alone. B) Use a calibrated voltage tester on all conductors.
Journeyman Electricians Certification Review Guide
[NENJE]
Question 17. In a three‑phase delta‑wye transformer, the primary is delta‑connected and the secondary is wye‑connected. What is the voltage relationship between line voltage on the secondary and phase voltage on the secondary? A) Line voltage = phase voltage B) Line voltage = √3 × phase voltage C) Line voltage = phase voltage ÷ √ D) No fixed relationship Answer: B Explanation: In a wye system, line voltage equals √3 times the phase voltage. Question 18. Which NEC article governs the installation of surge protective devices (SPDs) for residential premises? A) Article 210 B) Article 250 C) Article 285 D) Article 300 Answer: C Explanation: Article 285 addresses surge protection for dwellings. Question 19. A conduit run must be supported every 3 ft for non‑metallic conduit. Which NEC rule provides this requirement? A) 300. B) 352. C) 358. D) 376.
Journeyman Electricians Certification Review Guide
[NENJE]
Answer: B Explanation: NEC 352.30 specifies support spacing for PVC conduit. Question 20. Which type of cable is permitted for interior wiring of a residential kitchen branch circuit? A) UF‑B B) MC‑type C) NM‑B (Romex) D) AC‑type Answer: C Explanation: NM‑B is the standard non‑metallic sheathed cable allowed for interior residential wiring. Question 21. When performing a continuity test on a grounding electrode conductor, what reading on the ohmmeter indicates a proper connection? A) 0 Ω B) 5 Ω or less C) 10 Ω or less D) Any reading below 100 Ω Answer: B Explanation: NEC 250.53(A)(2) requires a resistance of 5 Ω or less for grounding electrode conductors. Question 22. The NEC defines a “dedicated circuit” as one that: A) Supplies only one type of load.
Journeyman Electricians Certification Review Guide
[NENJE]
Question 25. In a swimming pool area, which type of bonding conductor is required for the pool water pipe? A) 8 AWG copper B) 6 AWG copper C) 4 AWG copper D) 2 AWG copper Answer: C Explanation: NEC 680.26(A) requires a 4 AWG copper bonding conductor for pool water piping. Question 26. A solar photovoltaic (PV) array is rated at 500 V DC. What is the maximum permissible voltage for conductors feeding the inverter according to NEC 690.41? A) 300 V DC B) 600 V DC C) 1000 V DC D) 1500 V DC Answer: B Explanation: NEC 690.41 limits PV system conductors to 600 V DC maximum. Question 27. Which of the following is the correct method to calculate box fill for a standard device box containing three 12‑AWG conductors, a device, and a grounding conductor? A) Count each conductor as one fill unit, device as one, and ground as one. B) Count each conductor as one, ground as ½, and device as two. C) Count each conductor as one, ground as ½, and device as one.
Journeyman Electricians Certification Review Guide
[NENJE]
D) Count each conductor as one, ground as one, and device as two. Answer: C Explanation: NEC Table 314.16(B) assigns ½ unit for the grounding conductor and one unit for a device. Question 28. When installing a motor‑control center (MCC), the NEC requires that the enclosure be rated for which minimum NEMA type? A) NEMA 1 B) NEMA 3R C) NEMA 4X D) NEMA 12 Answer: C Explanation: MCCs typically require NEMA 4X rating for protection against dust, water, and corrosion. Question 29. For a Class II hazardous location, which of the following cable types is acceptable? A) Type NM‑B B) Type MC‑B with a metal jacket C) Type THHN in conduit only D) Type UF‑B buried directly Answer: B Explanation: MC‑B with a metal jacket is listed for Class II locations when installed per listing. Question 30. Which of the following statements about AFCI (Arc‑Fault Circuit Interrupter) protection is true?
Journeyman Electricians Certification Review Guide
[NENJE]
Question 33. A 120/240 V, 30 A dryer circuit requires a neutral conductor. What size (copper) neutral is required by NEC? A) 12 AWG B) 10 AWG C) 8 AWG D) 6 AWG Answer: B Explanation: For a 30 A dryer circuit, NEC 310.15(B)(16) requires a 10 AWG copper neutral. Question 34. Which of the following is the correct minimum clearance between a panelboard and the floor? A) 0 in (directly on the floor) B) 6 in C) 12 in D) 18 in Answer: B Explanation: NEC 110.26(A)(1) requires a minimum of 6 in clearance beneath the panelboard. Question 35. For a fire alarm initiating device installed in a suspended ceiling, the wiring must be protected from physical damage by: A) RMC conduit only. B) EMT conduit only. C) A listed raceway or cable tray. D) No protection required if within 12 in of the ceiling. Answer: C
Journeyman Electricians Certification Review Guide
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Explanation: NEC 760.41 requires fire alarm wiring to be in a listed raceway or cable tray to protect from damage. Question 36. A transformer’s primary is connected to a 480 V three‑phase source. The secondary is rated 240 V. What is the turns ratio? A) 1: B) 2: C) 1: D) 4: Answer: B Explanation: Turns ratio = Primary Voltage / Secondary Voltage = 480 V / 240 V = 2:1. Question 37. Which NEC article addresses the installation of low‑voltage fire alarm circuits? A) Article 760 B) Article 770 C) Article 800 D) Article 820 Answer: A Explanation: Article 760 covers fire alarm systems, including low‑voltage circuits. Question 38. In a commercial kitchen, a hood exhaust fan must be protected by a dedicated circuit. What is the minimum ampacity of the breaker if the fan is rated at 5 A? A) 15 A B) 20 A C) 30 A
Journeyman Electricians Certification Review Guide
[NENJE]
Question 41. Which of the following is the correct method to calculate the ampacity of a feeder that supplies a single‑family dwelling? A) Use NEC Table 310.15(B)(16) with a 75 °C column. B) Use the 90 °C column regardless of termination rating. C) Apply a 125 % demand factor for all loads. D) Use the smallest conductor size that fits in the conduit. Answer: A Explanation: For dwelling feeders, NEC Table 310.15(B)(16) with the 75 °C column is used, considering termination ratings. Question 42. In a Class III hazardous location, which type of lighting fixture is permitted? A) Standard incandescent fixture. B) Explosion‑proof LED fixture listed for Class III. C) Fluorescent fixture with a regular ballast. D) Halogen downlight without a listing. Answer: B Explanation: Only fixtures listed for Class III are allowed in that hazardous area. Question 43. When a circuit is protected by a 20 A breaker, what is the maximum continuous load allowed on that circuit? A) 20 A B) 16 A C) 24 A D) 30 A
Journeyman Electricians Certification Review Guide
[NENJE]
Answer: B Explanation: NEC requires continuous loads not to exceed 80 % of the breaker rating: 20 A × 0.8 = 16 A. Question 44. Which of the following statements about “knockout” fittings is true? A) They are required for all conduit entries into boxes. B) They are optional if the conduit is larger than 2 in. C) They must be listed for the type of conduit used. D) They can be fabricated on‑site from sheet metal. Answer: C Explanation: Knockouts must be listed for the specific conduit type to maintain the integrity of the enclosure. Question 45. A building’s emergency lighting system must be capable of providing illumination for how many minutes after a power loss? A) 5 minutes B) 15 minutes C) 30 minutes D) 60 minutes Answer: C Explanation: NEC 700.12 requires emergency lighting to operate for at least 90 minutes for most occupancies; however, the minimum is 30 minutes for certain areas. The most common requirement is 30 minutes; answer: C. Question 46. Which NEC article governs the installation of wiring methods for solar photovoltaic (PV) systems?
Journeyman Electricians Certification Review Guide
[NENJE]
Explanation: NEC 210.8 requires GFCI protection for feeders supplying certain occupancies; however, for a main feeder, a GFCI is not typically required unless required by specific occupancy. The more accurate answer is D. Correction: Answer: D – No ground‑fault device is required on a feeder unless the occupancy demands it. Question 49. In a commercial office, the NEC requires that all receptacle outlets in workstations be protected by: A) AFCI only. B) GFCI only. C) Both AFCI and GFCI. D) Either AFCI or GFCI, depending on the circuit. Answer: C Explanation: NEC 210.8(A) requires GFCI in many areas, and 210.12 requires AFCI protection for branch circuits supplying outlets in dwelling units; for commercial offices, only GFCI is mandatory. Therefore answer B is correct. Correction: Answer: B – GFCI only. Question 50. Which of the following is the correct clearance required between a service disconnect and a water pipe? A) 6 in B) 12 in C) 18 in D) No clearance required if the pipe is non‑metallic. Answer: A Explanation: NEC 110.26(A)(1) requires a minimum of 6 in clearance in front of service equipment.
Journeyman Electricians Certification Review Guide
[NENJE]
Question 51. When installing a 4‑wire feeder to a detached garage, which conductor is NOT required? A) Two hot conductors. B) One neutral conductor. C) One ground conductor. D) A separate equipment grounding conductor is optional. Answer: D Explanation: NEC 250.32 permits the use of the equipment grounding conductor as part of the feeder; a separate grounding conductor is not required if the neutral is used as a grounding path, but a dedicated grounding conductor is still preferred. The correct answer is D. Question 52. Which of the following devices is used to limit the inrush current to a motor during start‑up? A) Thermistor (NTC) starter. B) GFCI. C) AFCI. D) Surge protector. Answer: A Explanation: An NTC thermistor limits inrush current during motor start. Question 53. For a lighting circuit that serves 10 fixtures each rated 120 V × 150 W, what is the minimum breaker size? A) 15 A B) 20 A C) 30 A
