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Question 1. Which NEC article defines the requirements for electrical equipment identification and markings? A) Article 110 B) Article 210 C) Article 250 D) Article 300 Answer: A Explanation: Article 110 of the NEC covers requirements for equipment identification, labeling, and markings. Question 2. In OSHA 29 CFR 1926, which regulation specifically addresses fall protection for workers on ladders? A) Subpart C – General Safety and Health B) Subpart M – Fall Protection C) Subpart E – Personal Protective and Life Saving Equipment D) Subpart H – Materials Handling, Storage, and Use Answer: B Explanation: Subpart M of OSHA construction standards deals with fall protection, including ladder safety. Question 3. What is the primary purpose of a lockout/tagout (LOTO) procedure? A) To prevent chemical spills B) To ensure machines are de-energized before servicing C) To document daily work logs D) To label hazardous materials Answer: B
Explanation: LOTO is used to isolate energy sources and prevent accidental startup during maintenance. Question 4. Which of the following symbols on a blueprint indicates a three-phase panel? A) A single circle with “P” B) Three stacked squares with “3-Φ” C) A rectangle with “DP” D) A triangle with “Δ” Answer: B Explanation: Blueprint symbols for a three-phase panel typically show three stacked squares and the notation “ 3 - Φ”. Question 5. When performing a quantity take-off for conduit, which measurement is most critical? A) Conduit length in meters B) Conduit weight in kilograms C) Number of fittings per conduit run D) Voltage rating of the conduit Answer: A Explanation: Take-offs for conduit require accurate linear measurements to calculate material quantities. Question 6. In critical path method (CPM) scheduling, which activity has zero float? A) An activity that can be delayed without affecting the project end date B) The longest duration activity on the critical path
Question 9. NFPA 70E defines the “established approach boundary” for arc-flash protection. This boundary is measured from: A) The nearest grounded metal part B) The point where the arc-flash temperature reaches 1,200 °C C) The source of the arc-flash hazard D) The worker’s eye level Answer: C Explanation: The established approach boundary is the distance from the arc-flash source where a worker could be exposed to a flash without additional protection. Question 10. Which type of insulated tool is required when working on equipment rated for 600 V? A) Class 0 insulated tool B) Class 1 insulated tool C) Class 2 insulated tool D) Class 3 insulated tool Answer: D Explanation: Class 3 insulated tools provide protection for voltages up to 1,000 V, covering 600 V equipment. Question 11. Ohm’s Law states that voltage equals: A) Current divided by resistance B) Current times resistance C) Power divided by current D) Power times resistance Answer: B Explanation: Ohm’s Law is V = I × R.
Question 12. In a parallel circuit, the total resistance is: A) The sum of individual resistances B) The reciprocal of the sum of reciprocals of each resistance C) Equal to the highest individual resistance D) Always greater than any individual resistance Answer: B Explanation: For parallel resistors, 1/R_total = Σ(1/R_i). Question 13. A motor draws 15 A at 240 V. What is its apparent power in VA? A) 3,600 VA B) 2,500 VA C) 3,200 VA D) 3,000 VA Answer: A Explanation: VA = V × I = 240 V × 15 A = 3,600 VA. Question 14. If a load has a power factor of 0.8 lagging, what is the true power (kW) for a 5 kVA load? A) 4 kW B) 6.25 kW C) 3.2 kW D) 5 kW Answer: A Explanation: True power = kVA × PF = 5 kVA × 0.8 = 4 kW.
Question 18. What is the required working space width in front of a 600 V panelboard according to NEC 110.26? A) 30 inches B) 36 inches C) 42 inches D) 48 inches Answer: B Explanation: NEC 110.26 requires a minimum width of 36 inches for equipment rated up to 600 V. Question 19. In residential wiring, which color is used for the grounded (neutral) conductor? A) Black B) Red C) White D) Green Answer: C Explanation: White (or gray) is the standard color for neutral conductors. Question 20. A branch circuit supplying a kitchen countertop receptacle must be protected by a breaker no larger than: A) 15 A B) 20 A C) 30 A D) 40 A Answer: B
Explanation: NEC 210.11(C)(1) requires a 20-A maximum for kitchen countertop receptacles. Question 21. When selecting a circuit breaker for a motor, the breaker size is typically: A) 125 % of the motor’s full-load current B) 100 % of the motor’s full-load current C) 75 % of the motor’s full-load current D) 150 % of the motor’s full-load current Answer: A Explanation: NEC 430.32 permits a breaker size up to 125 % of the motor’s full-load current for standard duty motors. Question 22. Which conduit type is permitted for underground installation in wet locations? A) Rigid metal conduit (RMC) only B) PVC conduit (Schedule 40) only C) EMT conduit only D) Both RMC and PVC conduit Answer: D Explanation: Both RMC and PVC (Schedule 40/80) are approved for underground wet locations. Question 23. Derating of conductor ampacity is required when more than how many current-carrying conductors are installed in a single raceway? A) 2 B) 3
B) A space that contains only one piece of equipment of a specific function C) An area that can be used for any type of equipment D) A hallway that provides access to multiple panels Answer: B Explanation: A dedicated equipment space is reserved for a single piece of equipment and must not be shared. Question 27. Which NEC article governs the installation of luminaires in bathrooms? A) Article 210 B) Article 410 C) Article 422 D) Article 500 Answer: B Explanation: Article 410 covers luminaires, lampholders, and related equipment, including bathroom installations. Question 28. A fixed electric space-heating appliance must have an overcurrent protective device rated at no more than: A) 80 % of the appliance name-plate rating B) 100 % of the appliance name-plate rating C) 125 % of the appliance name-plate rating D) 150 % of the appliance name-plate rating Answer: C Explanation: NEC 422.13 requires overcurrent protection not to exceed 125 % of the appliance’s rating.
Question 29. Locked-rotor current (LRC) is used to determine the size of which protective device for a motor? A) Fuse B) Ground fault circuit interrupter (GFCI) C) Overload relay D) Surge protector Answer: C Explanation: LRC is the basis for selecting overload protection for motor circuits. Question 30. A transformer’s primary overcurrent protective device must be sized based on: A) The transformer’s secondary voltage B) The transformer’s primary full-load current plus 125 % C) The transformer’s secondary full-load current only D) The transformer’s impedance voltage Answer: B Explanation: NEC 450.3 requires the primary OCPD to be sized at 125 % of the transformer’s primary full-load current. Question 31. In a Class I, Division 2 hazardous location, which type of conduit is permitted? A) Rigid metal conduit (RMC) only B) PVC conduit without a seal C) Flexible metal conduit (FMC) with a sealing gland D) Any conduit as long as it is painted black Answer: C
C) 600 V AC
D) 30 V DC
Answer: D Explanation: The NEC defines low-voltage as systems 30 V or less. Question 35. When installing data cabling, the minimum separation from power conductors in the same raceway is: A) 0 in (same raceway allowed) B) 2 in C) 6 in D) 12 in Answer: C Explanation: NEC 800.113 requires a minimum of 6 in separation between power and communications conductors in the same raceway. Question 36. Fire alarm circuits that are power-limited must be protected by a fuse not exceeding: A) 5 A B) 15 A C) 20 A D) 30 A Answer: A Explanation: NEC 760.41 limits power-limited fire alarm circuits to a maximum of 5 A overcurrent protection. Question 37. The NEC permits the use of aluminum conductors for branch circuits up to what ampacity without a special rating?
A) 15 A
B) 20 A
C) 30 A
D) 40 A
Answer: C Explanation: Standard aluminum conductors (e.g., 12 AWG Al) are rated for up to 30 A in branch circuits. Question 38. Which of the following is a required marking on a receptacle intended for use in a wet location? A) “Dry Location Only” B) “Weather-Resistant” C) “GFCI Protected” D) “NEMA 4” Answer: B Explanation: NEC 406.7 requires receptacles in wet locations to be marked “Weather-Resistant”. Question 39. A circuit supplying a bathroom vanity light must be protected by a GFCI. Which NEC article mandates this? A) Article 210.8(A)(1) B) Article 210.11(C)(3) C) Article 210.52(B) D) Article 210.70(A) Answer: A Explanation: Article 210.8(A)(1) requires GFCI protection for receptacles in bathrooms; the same protection extends to lights if on the same circuit.
Explanation: The grounded conductor is the neutral, which is intentionally connected to ground at the service. Question 43. A motor-starting transformer must have its secondary overcurrent protection sized at: A) 100 % of the transformer’s secondary full-load current B) 125 % of the secondary full-load current C) 150 % of the secondary full-load current D) 200 % of the secondary full-load current Answer: B Explanation: NEC 450.9 requires secondary OCPD for motor-starting transformers to be not less than 125 % of the secondary full-load current. Question 44. When installing conduit in a concrete slab, the minimum concrete cover for PVC conduit is: A) 1 in B) 1½ in C) 2 in D) 2½ in Answer: B Explanation: NEC 300.5 requires a minimum of 1½ in concrete cover for PVC conduit. Question 45. Which of the following is a permissible method for bonding a metal raceway in a hazardous location? A) Using a non-conductive tape B) Installing a bonding jumper at each conduit end
C) Painting the raceway with insulating paint D) No bonding required in hazardous locations Answer: B Explanation: NEC 500.8 requires bonding jumpers at each end of metal raceways in hazardous locations. Question 46. For a 120/240 V single-phase residential service, the minimum size of the service-entrance conductors is: A) 14 AWG copper B) 12 AWG copper C) 6 AWG copper D) 4 AWG copper Answer: C Explanation: NEC Table 310.15(B)(16) indicates 6 AWG copper is the minimum for a 100 - A residential service; 120/240 V services typically require at least 6 AWG for 100 A. Question 47. Which NEC article addresses the installation of equipment in swimming pools? A) Article 250 B) Article 680 C) Article 690 D) Article 720 Answer: B Explanation: Article 680 covers swimming pool, spa, and hot tub installations.
Explanation: NEC 300.21 requires fire-stop seals to preserve the fire rating of walls. Question 51. The NEC defines “dedicated grounding electrode” as: A) Any metal pipe in contact with the earth B) A specific electrode installed solely for grounding the electrical system C) The neutral bus bar in a panel D) The equipment grounding conductor (EGC) Answer: B Explanation: A dedicated grounding electrode is a specific electrode (e.g., ground rod, Ufer) installed for grounding purposes only. Question 52. Which of the following devices provides both overcurrent and ground-fault protection for 120 V receptacles? A) Standard circuit breaker B) GFCI breaker C) AFCI breaker D) Fuse with a ground-fault detector Answer: B Explanation: GFCI breakers combine overcurrent (breaker) and ground-fault protection. Question 53. A conduit fill calculation for a ¾-in. EMT pipe containing eight #12 AWG THHN conductors must not exceed what percentage? A) 40 % B) 53 % C) 60 % D) 70 %
Answer: B Explanation: For more than two conductors, the maximum fill is 53 % of the conduit’s internal area. Question 54. Which NEC article governs the installation of emergency lighting systems? A) Article 410 B) Article 700 C) Article 725 D) Article 760 Answer: A Explanation: Article 410 includes provisions for emergency and exit lighting. Question 55. In a commercial kitchen, the minimum ampacity for a dedicated branch circuit feeding a 6 kW electric range is: A) 20 A B) 30 A C) 40 A D) 50 A Answer: C Explanation: A 6 kW range at 240 V draws 25 A; NEC 210.23(A)(2) requires a branch circuit rated at least 125 % of the load, which is 31.25 A, so a 40 A circuit is standard. Question 56. Which type of GFCI protection is required for receptacles installed in a garage? A) No GFCI required B) GFCI protected at the receptacle only
