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Question 1. Which NYC DOB license allows an individual to supervise all types of electrical work, including high-voltage installations? A) Special Electrician B) Master Electrician C) Apprentice Electrician D) Journeyman Electrician Answer: B Explanation: The Master Electrician license is the highest level, permitting supervision of all electrical work, including high-voltage and specialty installations, per NYC DOB regulations. Question 2. Under the NYC Administrative Code, how often must a Master Electrician’s license be renewed? A) Every 1 year B) Every 2 years C) Every 3 years D) Every 5 years Answer: B Explanation: NYC DOB requires renewal of Master Electrician licenses biennially, with proof of continuing education and insurance. Question 3. When submitting a permit through DOB NOW, which document must accompany a new commercial wiring permit? A) Proof of insurance only B) A signed contractor’s affidavit and site plan C) Only the contractor’s license copy D) No additional documents are required
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Answer: B Explanation: DOB NOW requires a signed contractor’s affidavit and a site plan showing the scope of work for commercial wiring permits. Question 4. An ECB violation for “Improper grounding” carries a minimum fine of: A) $ B) $ C) $1, D) $2, Answer: C Explanation: The Environmental Control Board sets a minimum $1,000 fine for grounding violations to enforce safety. Question 5. The “direct and continuing supervision” requirement for NYC electricians means the supervising Master must be: A) On-site at all times during work B) Available by telephone only C) Present only during inspections D) Able to delegate supervision to a foreman Answer: A Explanation: NYC law mandates that the supervising Master be physically present on the job site for the duration of the work. Question 6. In NYC EC Article 200, the grounded (neutral) conductor must be identified by which color? A) Black B) White or gray
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A) Standard method only B) Optional method only C) Either standard or optional, as long as the result meets the load requirement D) No calculation is required for feeders under 100 A Answer: C Explanation: NYC permits either the standard or optional calculation method, provided the feeder meets or exceeds the calculated load. Question 10. The demand factor for a kitchen with three 20-amp small-appliance branch circuits is: A) 100% B) 80% C) 60% D) 50% Answer: B Explanation: NEC Article 220.55 provides an 80% demand factor for the first 12 kW of kitchen small-appliance loads. Question 11. According to Article 200, the maximum allowable voltage drop for feeder conductors serving a single-family dwelling is: A. 2% B. 3% C. 5% D. 10% Answer: B Explanation: NEC recommends a maximum of 3% voltage drop for feeders to maintain efficiency and performance.
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Question 12. The minimum clearance between an exterior branch circuit conduit and a fire escape stairwell in NYC is: A) 12 in. B) 18 in. C) 24 in. D) 30 in. Answer: C Explanation: NYC EC Article 300.23 requires a 24-inch clearance from fire escape stairwells to protect against damage and fire spread. Question 13. When installing a grounding electrode conductor (GEC) for a new single-family home, the minimum size of copper conductor required is: A) #10 AWG B) #8 AWG C) #6 AWG D) #4 AWG Answer: B Explanation: NEC 250.68(A) specifies a minimum of #8 AWG copper GEC for residential grounding electrodes. Question 14. Bonding of a metal water pipe that is part of a building’s plumbing system must be performed at: A) The service disconnect only B) The nearest accessible point to the water main C) Each fixture location D) Only at the point of entry into the building Answer: B
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D) 1.
Answer: C Explanation: The ambient temperature is within the standard 30 °C range, so no correction factor is applied; ampacity remains unchanged. Question 18. When calculating conduit fill, the maximum allowable fill for a raceway containing more than two conductors is: A) 40% of the internal cross-sectional area B) 31% of the internal cross-sectional area C) 53% of the internal cross-sectional area D) 25% of the internal cross-sectional area Answer: B Explanation: NEC Chapter 9, Table 1, specifies a 31% fill limit for raceways with three or more conductors. Question 19. The required working space in front of a panelboard rated 600 A or less is: A) 30 in. wide, 36 in. deep, 6 ft. high B) 36 in. wide, 30 in. deep, 6 ft. high C) 30 in. wide, 30 in. deep, 6 ft. high D) 36 in. wide, 36 in. deep, 6 ft. high Answer: A Explanation: NEC 110.26(A)(1) mandates a minimum 30-in. wide, 36-in. deep, and 6-ft. high working space for panelboards ≤ 600 A. Question 20. A luminaire installed in a closet must be listed for which type of location? A) Damp location
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B) Wet location C) Dry location only D) Hazardous (Class I) location Answer: C Explanation: Closets are considered dry locations; luminaires must be listed for dry locations only. Question 21. The minimum ampacity of an equipment grounding conductor (EGC) for a 20-amp branch circuit with 12-AWG copper conductors is: A) #14 AWG copper B) #12 AWG copper C) #10 AWG copper D) #8 AWG copper Answer: B Explanation: NEC Table 250.122 requires the EGC to be the same size as the phase conductors for a 20-amp circuit, which is #12 AWG. Question 22. A motor rated 15 hp, 460 V, 3-phase requires a branch circuit breaker sized at: A) 125 % of full-load current (FLC) B) 150 % of FLC C) 200 % of FLC D) 250 % of FLC Answer: B Explanation: NEC 430.32 requires motor branch-circuit protection at 150 % of the motor’s FLC for standard motors.
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Explanation: NEC 250.30 requires a separately derived system to have its own grounding electrode system to isolate it from the building’s grounded system. Question 26. An emergency lighting circuit must be supplied from a branch circuit with a rating of at least: A) 15 A B) 20 A C) 30 A D) 40 A Answer: B Explanation: NEC 700.12 requires emergency lighting circuits to be supplied from a minimum 20-amp branch circuit. Question 27. The minimum size of a grounding electrode conductor for a 400 - A service using copper is: A) #8 AWG B) #6 AWG C) #4 AWG D) #2 AWG Answer: C Explanation: NEC Table 250.66 indicates a #4 AWG copper GEC is required for services up to 400 A. Question 28. When installing MC cable in a commercial building, the maximum number of conductors permitted inside a single raceway without derating is: A) 3 B) 6
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C) 9
D) 12
Answer: B Explanation: NEC Table 310.15(B)(3)(a) allows up to 6 current-carrying conductors before applying derating factors for MC cable. Question 29. A 120/240-V single-phase service entrance must have a neutral that is: A) Isolated from ground at the service disconnect B) Bonded to ground at the service disconnect C) Not connected to the service panel at all D) Connected only at the transformer Answer: B Explanation: NEC 250.24(A)(1) requires neutral-ground bonding at the service disconnect for single-phase services. Question 30. The required minimum clearance between a low-voltage (LV) conduit and a high-voltage (HV) conduit in the same raceway assembly is: A) 1 in. B) 2 in. C) 3 in. D) No clearance required if separate conduit is used Answer: D Explanation: When separate conduits are used, no clearance is required between LV and HV conductors per NEC 300.3(C)(1).
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Explanation: NEC Table 250.122 specifies #6 AWG copper for motors with a 30 - amp rating, which is typical for a 3-phase 480 V motor of this size. Question 34. A building’s fire alarm system must be powered by an independent source that is: A) Connected to the normal building power with a transfer switch B) Completely isolated from any other building circuits C) Fed through a shared panelboard with lighting circuits D) Powered only by battery backup, no mains supply required Answer: B Explanation: NFPA 72 requires fire alarm systems to have an independent power source isolated from other building loads to ensure reliability. Question 35. In a Class II, Division 1 hazardous location, which type of cable is acceptable for power distribution? A) NM-B (Romex) B) MC cable with listed hazardous-location jacket C) UF cable D) AC cable Answer: B Explanation: MC cable with a hazardous-location rating is permitted; NM-B, UF, and AC are not allowed in Class II hazardous areas. Question 36. The required ampacity of a feeder supplying a 10-kW air-conditioning unit in a 5-unit residential building is calculated using which demand factor? A) 100% of the unit rating B) 75% of the unit rating plus 30% of the remainder
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C) 50% of the unit rating plus 30% of the remainder D) 40% of the unit rating plus 35% of the remainder Answer: B Explanation: NEC 220.84 provides a demand factor of 75% for the first 10 kW of AC load, then 30% for additional load. Question 37. For a commercial building with a total connected load of 250 kW, the minimum size of the main service disconnect is: A) 200 A B) 300 A C) 400 A D) 500 A Answer: C Explanation: Using NEC 220.42, a 250 kW load at 277 V (line-to-line) translates to approximately 520 A; the next standard size is 400 A with a demand factor, but NYC requires rounding up to the next standard size, 500 A; however, the correct answer per code calculations is 400 A after applying the 125% demand factor for commercial loads. Question 38. The minimum size of a grounding electrode conductor for a 600 - A service using aluminum is: A) #6 AWG B) #4 AWG C) #2 AWG D) #1/0 AWG Answer: D Explanation: NEC Table 250.66 specifies #1/0 AWG aluminum for services between 500 A and 600 A.
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Explanation: FMC can be used in fire-rated walls only if the conduit and fittings are listed for such use. Question 42. The maximum temperature rating for a conductor used in a conduit buried in a 95 °F ambient environment is: A) 60 °C B) 75 °C C) 90 °C D) 105 °C Answer: C Explanation: Conductors with a 90 °C rating are allowed in ambient temperatures up to 95 °F (35 °C) per NEC Table 310.15(B)(1). Question 43. A transformer supplying a separate building must have its secondary grounded in which manner? A) Using the building’s main grounding electrode only B) Using a dedicated grounding electrode for the transformer C) Not grounded at all D) Grounded through the primary side only Answer: B Explanation: NEC 250.30 requires a separate grounding electrode for separately derived systems, such as a transformer feeding another building. Question 44. The minimum clearance required between a panelboard and a combustible wall in a NYC commercial space is: A) 6 in. B) 12 in. C) 18 in.
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D) 24 in. Answer: B Explanation: NEC 110.26(A)(2) mandates a 12-inch clearance from the front of the panelboard to any combustible material. Question 45. Which of the following is an acceptable method for bonding a metal conduit system in a commercial building? A) Bond each conduit individually with a grounding screw B) Bond the entire raceway at the first box or enclosure C) No bonding is required if the conduit is metal D) Use a separate grounding wire run parallel to the conduit Answer: B Explanation: NEC 250.118 permits bonding the entire metal raceway system at the first enclosure or box. Question 46. The required size of a feeder conductor for a 100-A service feeding a 3-phase, 208-V panel is: A) #4 AWG copper B) #2 AWG copper C) #1/0 AWG aluminum D) #3/0 AWG aluminum Answer: B Explanation: NEC Table 310.15(B)(16) shows #2 AWG copper is rated for 115 A at 75 °C, satisfying a 100-A feeder. Question 47. For a building with a standby generator, the transfer switch must be: A) Manual only
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Question 50. Which of the following is the correct method for grounding a communications cable raceway in a commercial building? A) No grounding required for communications raceways B) Ground each individual cable within the raceway C) Bond the raceway to the building grounding system at each enclosure D) Use a separate grounding conductor run alongside the raceway Answer: C Explanation: NEC 800.151 requires bonding the communications raceway to the building grounding system at each termination point. Question 51. The maximum number of 15-amp receptacles allowed on a single 20-amp branch circuit in a dwelling unit is: A) 8 B) 10 C) 12 D) No limit, as long as the load does not exceed 80% of the breaker rating Answer: D Explanation: NEC does not set a numeric limit; the total load must not exceed 80 % of the breaker’s rating (16 A for a 20-A circuit). Question 52. For a 240 V, 30-amp dryer circuit, the required size of the equipment grounding conductor (EGC) is: A) #14 AWG copper B) #12 AWG copper C) #10 AWG copper D) #8 AWG copper Answer: B
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Explanation: NEC Table 250.122 indicates #12 AWG copper for circuits up to 30 A. Question 53. A building’s fire alarm wiring must be installed using which of the following methods? A) NM-B cable only B) Rigid metal conduit (RMC) only C) Any listed wiring method approved for fire alarm systems D) AC cable with metal armor Answer: C Explanation: NEC 760 permits any wiring method that is listed for fire alarm systems, including MC, conduit, or listed fire-alarm cable. Question 54. The minimum clearance between a low-voltage (LV) panel and a combustible ceiling in a commercial space is: A) 6 in. B) 12 in. C) 18 in. D) 24 in. Answer: B Explanation: NEC 110.26 requires a 12-inch clearance from the front of LV equipment to combustible surfaces. Question 55. When installing a receptacle in a wet location outdoors, which of the following is required? A) A standard duplex receptacle with a weather-proof cover B) A GFCI receptacle with a weather-proof in-let cover C) Any receptacle as long as it is UL listed
