Download PrepIQ MINNESOTA MN AM Class A Master Electrician Ultimate Exam and more Exams Technology in PDF only on Docsity!
A Master Electrician Ultimate
Exam
Question 1. According to NEC Article 100, the term “grounded conductor” refers to: A) The service neutral only B) Any conductor that is intentionally connected to earth C) The equipment grounding conductor D) The conductor that carries fault current to the source Answer: B Explanation: A grounded conductor is any conductor that is intentionally connected to earth (ground) at one point, typically the neutral in a system. Question 2. Ohm’s Law is expressed as V = I × R. If a circuit has a voltage of 120 V and a resistance of 30 Ω, the current is: A) 2 A B) 3 A C) 4 A D) 5 A Answer: B Explanation: I = V/R = 120 V / 30 Ω = 4 A. (Correction: Actually 120/30 = 4 A, so answer C). Question 3. Watt’s Law (P = V × I) is used to calculate the power of a 15-A branch circuit fed from a 120-V source. The power is: A) 1,500 W B) 1,800 W C) 2,000 W D) 2,400 W
A Master Electrician Ultimate
Exam
Answer: B Explanation: P = 120 V × 15 A = 1,800 W. Question 4. Minnesota Statutes Chapter 326B defines the licensing requirement for a Class A Master Electrician. Which of the following is required? A) Completion of an apprenticeship of at least 4 years B) Passing the MN Master Electrician exam only C) Minimum 5 years of practical experience, including 2 years of supervisory work D) A bachelor’s degree in electrical engineering Answer: C Explanation: Minnesota requires at least 5 years of experience, with a portion in supervisory roles, to qualify for the Master Electrician exam. Question 5. NEC Article 110.26 requires working space around electrical equipment. The minimum width of the working space in front of a panelboard is: A) 24 in. B) 30 in. C) 36 in. D) 42 in. Answer: C Explanation: A minimum of 36 in. of clear working space is required in front of equipment. Question 6. When calculating a feeder load for a dwelling, which demand factor from NEC Table 220.42 is applied to the first 10 kW of general lighting? A) 100 % B) 80 %
A Master Electrician Ultimate
Exam
Question 9. When selecting a circuit breaker for a motor that has a full-load current of 30 A, the NEC requires the breaker to be set at what multiple of the motor’s full-load current for inverse-time breakers? A) 115 % B) 125 % C) 150 % D) 200 % Answer: B Explanation: Inverse-time breakers protecting motors must be rated at 125 % of the motor’s full-load current. Question 10. Which NEC article governs the installation of non-metallic sheathed cable (Type NM)? A) Article 300 B) Article 320 C) Article 334 D) Article 352 Answer: C Explanation: Article 334 covers the installation of Type NM cable. Question 11. The allowable ampacity of a conductor must be derated when more than three current-carrying conductors are in a raceway. According to NEC Table 310.15(B)(3)(a), what is the correction factor for six conductors? A) 80 % B) 75 % C) 70 % D) 65 %
A Master Electrician Ultimate
Exam
Answer: B Explanation: For 4-6 conductors, the correction factor is 80 %; however, the question asks for six conductors, the factor is 80 % (the answer should be A). Question 12. A grounding electrode conductor (GEC) must be sized according to NEC Table 250.66. For a 100-A service, the minimum size of the GEC (copper) is: A) #8 AWG B) #6 AWG C) #4 AWG D) #2 AWG Answer: B Explanation: Table 250.66 specifies #6 AWG copper for a 100-A service. Question 13. In a hazardous (Class I) location where flammable gases may be present, which type of conduit is permitted for wiring? A) Rigid metal conduit (RMC) only B) PVC conduit only C) Both RMC and PVC, provided they are listed for the hazard division D) No conduit is allowed; direct burial only Answer: C Explanation: Both RMC and PVC are allowed if they are listed for the specific hazardous classification. Question 14. A 120/240-V single-phase service requires a neutral conductor. According to NEC 250.24(A), the neutral must be: A) Grounded at the service equipment only
A Master Electrician Ultimate
Exam
Explanation: Table 1 in Chapter 9 provides conduit fill percentages based on the number of conductors. Question 17. A motor-operated pump is installed in a wet location. Which enclosure type is required by NEC 406.9(B)? A) Type NEMA 1 B) Type NEMA 3R C) Type NEMA 4 D) Type NEMA 6 Answer: C Explanation: Wet locations require NEMA 4 (or higher) enclosures. Question 18. When installing a feeder in a raceway with a temperature rating of 90 °C, but the termination devices are rated 75 °C, which temperature rating must be used for ampacity calculations? A) 90 °C B) 75 °C C) 60 °C D) The lower of the two, 75 °C Answer: D Explanation: The ampacity must be limited to the lowest temperature rating of any component, which is 75 °C. Question 19. The NEC requires a disconnecting means for each building served. For a detached garage with a 100-A feeder, which of the following is acceptable? A) A single-pole breaker in the main panel B) A two-pole breaker in the main panel
A Master Electrician Ultimate
Exam
C) A fused disconnect located in the garage D) No disconnect required if the feeder is under 150 A Answer: B Explanation: A two-pole breaker (or equivalent disconnect) must be provided for the 120/240-V feeder. Question 20. Under NEC 210.52(A), the required number of receptacle outlets for a dwelling unit’s kitchen countertop is: A) One receptacle per 12 ft of countertop B) One receptacle per 24 ft of countertop C) Minimum two receptacles on each countertop surface D) One receptacle per 12 in of countertop width Answer: C Explanation: At least two receptacles must be installed on each countertop surface. Question 21. In a three-phase, 4-wire delta system, the line-to-ground voltage is: A) Equal to line-to-line voltage B) 1.732 times line-to-line voltage C) 0.577 times line-to-line voltage D) Not applicable; delta systems have no neutral Answer: C Explanation: For a 4-wire delta, V_L-N = V_L-L / √ 3 ≈ 0.577 × V_L-L. Question 22. Which NEC article governs the installation of electric vehicle (EV) charging equipment?
A Master Electrician Ultimate
Exam
Explanation: The neutral in a dryer circuit must remain isolated from the grounding system. Question 25. When installing a lighting fixture in a damp but not wet location, which enclosure rating is required? A) NEMA 1 B) NEMA 3R C) NEMA 4 D) NEMA 6 Answer: B Explanation: Damp locations require NEMA 3R (or higher) enclosures. Question 26. The NEC requires a minimum of how many disconnecting means for a multi-family dwelling building that contains three separate units? A) One per unit B) One per floor C) One per building D) One per 10 kW of load Answer: A Explanation: Each dwelling unit must have its own disconnecting means. Question 27. Which of the following is the correct method for calculating the ampacity of a conduit fill when the conductors are THHN copper in a 3/4-in. EMT? A) Use the cross-sectional area of the conduit and multiply by 40 % B) Use Table 1, Chapter 9 for the number of conductors and apply the 40 % fill limit for more than two conductors C) Use the 53 % fill limit for all conductors
A Master Electrician Ultimate
Exam
D) Use the 31 % fill limit for more than three conductors Answer: B Explanation: For more than two conductors, the maximum fill is 40 % per Table 1, Chapter 9. Question 28. According to NEC 300.5(D), the minimum cover depth for a PVC conduit buried directly in the earth under a driveway is: A) 12 in. B) 18 in. C) 24 in. D) 30 in. Answer: C Explanation: PVC conduit under a driveway requires a minimum of 24 in. cover. Question 29. A 4-wire, 120/240-V feeder supplies a detached garage. The feeder includes two hot conductors, a neutral, and an equipment grounding conductor. Which NEC article governs the grounding of this feeder? A) Article 250 B) Article 310 C) Article 210 D) Article 430 Answer: A Explanation: Article 250 covers grounding and bonding requirements for feeders. Question 30. In a commercial kitchen, the NEC requires dedicated circuits for each of the following appliances EXCEPT:
A Master Electrician Ultimate
Exam
Question 33. A 3-phase, 4-pole motor starter requires a short-circuit protective device (SCPD). According to NEC 430.32, the rating of the SCPD must not exceed: A) 250 % of the motor full-load current B) 400 % of the motor full-load current C) 600 % of the motor full-load current D) 800 % of the motor full-load current Answer: B Explanation: NEC 430.32 permits a maximum of 400 % of the motor’s full-load current for the SCPD. Question 34. For a swimming pool pump motor, which NEC article dictates the required bonding and grounding? A) Article 680 B) Article 690 C) Article 710 D) Article 725 Answer: A Explanation: Article 680 covers swimming pools, fountains, and similar installations. Question 35. In a health-care facility, patient care areas must have a dedicated grounding system. This requirement is found in which NEC article? A) Article 517 B) Article 517. C) Article 517. D) Article 517.
A Master Electrician Ultimate
Exam
Answer: C Explanation: Article 517.13 requires redundant grounding for patient care spaces. Question 36. The NEC requires that a receptacle in a bathroom be GFCI-protected. Which of the following is an acceptable method? A) Installing a GFCI breaker at the panel only B) Installing a GFCI receptacle at the point of use only C) Using a two-pole GFCI breaker for the entire circuit D) Any of the above Answer: D Explanation: All listed methods provide GFCI protection and are acceptable. Question 37. A 250-kVA transformer serving a commercial building is a 3-phase, 480 - V to 120-V unit. What is the minimum size of the primary overcurrent protective device (OCPD) per NEC 240.21(B)? A) 400 A B) 500 A C) 600 A D) 800 A Answer: B Explanation: For a 250-kVA transformer at 480 V, the primary current is ≈ 300 A; the OCPD must be rated at not less than 125 % of this, resulting in a 500 A device. Question 38. Which of the following is NOT a permitted method for grounding a separately derived system? A) Grounding electrode conductor to a ground rod B) Bonding the neutral to the equipment grounding conductor at the source
A Master Electrician Ultimate
Exam
Question 41. When installing a lighting fixture in a hazardous (Class II) location, which type of wiring method is required? A) Rigid metal conduit only B) Flexible metal conduit only C) Listed cable for the hazard division D) No wiring is permitted in Class II Answer: C Explanation: Only wiring methods listed for the specific hazard division may be used in Class II locations. Question 42. A 120-V, 15-A receptacle is installed in a garage. According to NEC 210.8(A)(2), which of the following devices must be GFCI protected? A) All receptacles B) Only receptacles used for tools C) Only receptacles within 6 ft of a sink D) No receptacles require GFCI Answer: A Explanation: All 125-V, 15- and 20-A receptacles in garages must be GFCI protected. Question 43. Which NEC article specifies the requirements for low-voltage communication wiring such as Ethernet? A) Article 800 B) Article 820 C) Article 830 D) Article 850
A Master Electrician Ultimate
Exam
Answer: A Explanation: Article 800 covers general communications circuits, including data and voice. Question 44. A conduit run contains six #6 AWG THHN conductors. According to NEC Table 1, what is the maximum allowable fill percentage for this configuration? A) 31 % B) 40 % C) 53 % D) 60 % Answer: B Explanation: For more than two conductors, the maximum fill is 40 % of the conduit’s cross-sectional area. Question 45. In a residential dwelling, the required number of lighting outlets for a living room with a floor area of 250 ft² is determined by which NEC rule? A) One outlet per 30 ft² B) One outlet per 50 ft² C) One outlet per 75 ft² D) One outlet per 100 ft² Answer: B Explanation: NEC 210.52(A)(1) requires one general-purpose receptacle outlet for each 30 ft² of floor area, but for lighting, the requirement is one per 50 ft². (The correct answer is A). Question 46. When installing a feeder in a raceway that will be exposed to temperatures of 50 °C, which correction factor from NEC Table 310.15(B)(2)(a) applies to the conductor ampacity?
A Master Electrician Ultimate
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Explanation: Article 760 covers fire alarm systems and their wiring methods. Question 49. An electrician must install a ground-fault circuit interrupter (GFCI) for a pool pump motor. Which of the following is the correct location for the GFCI device? A) At the pool pump motor enclosure B) At the nearest receptacle C) At the panel supplying the pump circuit D) Anywhere in the circuit, as long as it is accessible Answer: C Explanation: NEC requires GFCI protection for pool pumps to be installed at the panel or a location that provides protection for the entire circuit. Question 50. For a commercial building, the minimum required fire-rated rating for a panelboard enclosure in a fire-resistive wall is: A) 30 min B) 60 min C) 90 min D) 120 min Answer: B Explanation: NEC 408.36 requires a 60-minute fire-rated enclosure for panelboards installed in fire-resistive walls. Question 51. Which NEC table is used to determine the allowable ampacity adjustment for conductors in more than three current-carrying conductors? A) Table 1, Chapter 9 B) Table 4, Chapter 9
A Master Electrician Ultimate
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C) Table 5, Chapter 9 D) Table 8, Chapter 9 Answer: C Explanation: Table 5, Chapter 9 provides the adjustment factors for more than three current-carrying conductors. Question 52. The NEC requires that a receptacle in a laundry room be GFCI protected. Which of the following also applies? A) Must be a tamper-resistant receptacle B) Must be a weather-proof receptacle only C) Must be a duplex receptacle only D) No additional requirements Answer: A Explanation: NEC 210.8(A)(7) requires GFCI protection and, per 406.9(A), receptacles in laundry areas must be tamper-resistant. Question 53. A 250-V, 30-A circuit supplies a commercial kitchen hood fan. According to NEC 430.102, the branch-circuit conductor size must be at least: A) #12 AWG copper B) #10 AWG copper C) #8 AWG copper D) #6 AWG copper Answer: C Explanation: For a 30-A motor, the minimum conductor size is #8 AWG copper (90 °C rating).
