Download Wyoming Electrical Specialty Exam Practice Questions and more Exams Technology in PDF only on Docsity!
Question 1. Which NEC article defines the requirements for grounding electrode systems? A) Article 250 B) Article 210 C) Article 430 D) Article 690 Answer: A Explanation: Article 250 of the NEC covers grounding and bonding, including grounding electrode systems. Question 2. In a three‑phase, four‑wire wye system, the neutral conductor carries current equal to: A) The sum of the three phase currents B) Zero, because the phases are balanced C) The vector sum of the phase currents D) The same as any one phase current Answer: C Explanation: The neutral carries the vector (phasor) sum of the three phase currents, which is zero only if the loads are perfectly balanced. Question 3. The minimum size of a service‑entrance conductor for a 200 A residential service, using copper conductors, is: A) 2 AWG B) 4 AWG C) 6 AWG D) 8 AWG Answer: B Explanation: Per NEC Table 310.15(B)(16), 4 AWG copper is rated for 200 A under typical conditions. Question 4. When calculating voltage drop, which factor is NOT considered? A) Conductor length B) Conductor resistance
C) Load power factor D) Ambient temperature Answer: D Explanation: Voltage‑drop calculations use length, resistance (or reactance), and load current (including power factor), but not ambient temperature. Question 5. A GFCI receptacle must be installed in which of the following locations? A) Unfinished basement closets B) Outdoor wet locations C) Inside a dry attic D) All of the above Answer: B Explanation: NEC 210.8(A)(3) requires GFCI protection for outdoor receptacles in wet locations. Question 6. The ampacity correction factor for a conduit that is more than 75 % filled with conductors is: A) 0. B) 0. C) 0. D) 0. Answer: B Explanation: NEC Table 310.15(C)(1) provides a 0.70 factor when conduit fill exceeds 75 %. Question 7. Which of the following is a permissible use for a flexible metal conduit (FMC)? A) Exposed in a wet location above grade B) Within a building for short runs to equipment C) As a raceway for fire‑alarm wiring in a plenary space D) All of the above Answer: B
Question 11. The minimum burial depth for PVC conduit containing a single 120 V circuit under a driveway is: A) 12 in. B) 18 in. C) 24 in. D) 30 in. Answer: B Explanation: NEC 300.5(D) requires 18 in. of cover for PVC under a driveway when the circuit is 120 V. Question 12. Which NEC article governs the installation of luminaires in hazardous (Class I) locations? A) Article 410 B) Article 500 C) Article 517 D) Article 590 Answer: B Explanation: Article 500 covers classification, installation, and equipment requirements for hazardous locations. Question 13. The purpose of a main disconnecting means at a service entrance is to: A) Provide a backup power source B) Isolate the entire service from the utility C) Reduce voltage to downstream circuits D) Protect against ground faults only Answer: B Explanation: The main disconnect isolates the entire service from the utility supply for safety and maintenance.
Question 14. When sizing a feeder for a commercial building with a calculated load of 120 kVA at 0.8 power factor, the minimum conductor ampacity (copper) should be: A) 200 A B) 250 A C) 300 A D) 350 A Answer: B Explanation: Apparent current = kVA / (√3 × V) = 120 kVA / (1.732 × 208 V) ≈ 335 A. Applying 0.8 demand factor reduces to ≈ 268 A; next standard size is 250 A with 75 °C rating, so 250 A is selected. Question 15. A receptacle required in a kitchen countertop must be spaced no more than: A) 12 ft apart B) 18 ft apart C) 24 ft apart D) 30 ft apart Answer: B Explanation: NEC 210.52(C)(1) mandates receptacles no more than 18 ft apart measured along the countertop. Question 16. Which of the following is NOT a permitted method for bonding metal water piping to the grounding electrode system? A) Directly to the grounding electrode conductor B) Using a bonding jumper of at least 8 AWG copper C) Through a listed grounding clamp on the pipe D) By connecting only to the service neutral bus Answer: D Explanation: Bonding must be made directly to the grounding electrode system, not merely to the neutral bus. Question 17. The NEC requires AFCI protection for which type of circuit?
B) A listed surge protective device C) A dedicated disconnecting means within sight of the pump D) An AFCI breaker Answer: C Explanation: NEC 695.4 requires a dedicated disconnect within sight of the fire pump. Question 21. The required minimum size of a grounding‑bonding conductor for a 3‑phase, 4‑wire feeder rated at 400 A is: A) 6 AWG copper B) 4 AWG copper C) 2 AWG copper D) 1/0 AWG copper Answer: B Explanation: NEC Table 250.122 specifies 4 AWG copper for a 400 A feeder. Question 22. When installing a metal raceway in a hazardous location, the raceway must be: A) Listed for the specific class and division B) Painted with anti‑corrosive coating C) Grounded only at the source end D) Filled with a non‑flammable gas Answer: A Explanation: Hazardous‑location raceways must be listed for the specific class/division per Article 500. Question 23. The NEC allows the use of a 12 AWG copper conductor for a 20 A branch circuit feeding a receptacle in a bathroom, provided: A) The circuit also supplies a dedicated lighting load B) The receptacle is GFCI protected C) The conduit fill does not exceed 40 % D) The circuit length is less than 100 ft
Answer: B Explanation: NEC 210.8(A)(1) requires GFCI protection for bathroom receptacles, allowing the standard 12 AWG/20 A conductor. Question 24. Which of the following is a required feature of a temporary service panel used on a construction site? A) Integral surge protection B) Lockable main disconnect C) Built‑in arc‑fault protection D) Battery backup Answer: B Explanation: NEC 590.4 requires temporary service panels to have a lockable main disconnect for security. Question 25. The NEC defines a “service” as: A) Any wiring system that distributes power within a building B) The point at which the utility’s conductors connect to the building’s wiring C) Only the main service entrance equipment D) The combination of all feeders and branch circuits Answer: B Explanation: Article 100 defines “service” as the point where utility conductors connect to the building’s wiring. Question 26. For a 125 kVA, 480 V, three‑phase transformer, the minimum size of the overcurrent protective device (OCPD) protecting the secondary is: A) 150 A B) 200 A C) 250 A D) 300 A Answer: B
A) 12 AWG
B) 10 AWG
C) 8 AWG
D) 6 AWG
Answer: B Explanation: NEC 210.23(A)(2) permits 10 AWG copper for a 30 A dryer circuit. Question 31. In a Class I, Division 2 hazardous location, the wiring method allowed for power circuits is: A) NM‑B cable B) MC cable with appropriate listing C) Rigid metal conduit only D) PVC conduit without listing Answer: B Explanation: MC cable listed for Class I, Division 2 is permissible; NM‑B is not allowed in hazardous locations. Question 32. The NEC requires a disconnecting means for a permanently installed motor that is: A) Within 6 ft of the motor B) Within sight of the motor C) No more than 30 ft away D) At the main panel only Answer: B Explanation: NEC 430.102 requires the disconnect to be within sight of the motor. Question 33. A solar photovoltaic (PV) array rated at 5 kW, 240 V DC must have a dedicated disconnect that is capable of opening at least: A) 20 A B) 30 A C) 40 A
D) 50 A
Answer: B Explanation: NEC 690.13 requires a disconnect rated not less than the array’s maximum current; 5 kW/240 V = 20.8 A, so a 30 A disconnect is required. Question 34. Which of the following is the correct method to calculate box fill for a device box containing a single-gang receptacle? A) One conductor per terminal plus one for the equipment grounding conductor B) Two conductors per terminal plus one for the equipment grounding conductor C) One conductor per terminal only D) No conductors are counted for the equipment grounding conductor Answer: A Explanation: NEC 314.16(B) counts one conductor for each ungrounded and grounded conductor and one for the equipment grounding conductor. Question 35. The required minimum size of a grounding‑electrode conductor for a 250 kVA, 13.8 kV transformer is: A) 4/0 AWG copper B) 250 kcmil aluminum C) 350 kcmil copper D) 500 kcmil aluminum Answer: A Explanation: NEC Table 250.66 shows 4/0 AWG copper for transformers between 250 kVA and 600 kVA. Question 36. Which of the following is a required feature of a spill‑containment basin at a fuel transfer point? A) Capacity of at least 10 % of the largest tank volume B) Capacity of at least 110 % of the largest single delivery volume C) Capacity of at least 5 % of the total on‑site fuel inventory D) Capacity of at least 50 % of the largest tank volume
Explanation: Infrared temperature sensors are not standard for suction line leak detection; flow, pressure, and shut‑off devices are. Question 40. When responding to a release alarm, the first action an operator must take is: A) Notify the fire department B) Shut down the affected transfer pump C) Begin product recovery procedures D) Document the alarm in the logbook Answer: B Explanation: Immediate isolation of the source (shutting down the pump) is required to stop further release. Question 41. The required minimum thickness of a secondary containment dike surrounding a double‑walled tank is: A) 1 in. B) 2 in. C) 3 in. D) 4 in. Answer: B Explanation: Most regulations mandate at least 2 in. thickness for secondary containment structures. Question 42. Which of the following is considered a “critical” component that must be inspected weekly on an AST? A) Paint condition on the tank shell B) Secondary containment integrity C) Leak‑detection system calibration D) All of the above Answer: D Explanation: All listed items are critical and require regular inspection per AST operational standards.
Question 43. The maximum allowable pressure for a vented, above‑ground gasoline tank with a capacity of 5,000 gal is: A) 2 psig B) 5 psig C) 10 psig D) 15 psig Answer: B Explanation: EPA regulations limit vented gasoline tanks to a maximum of 5 psig. Question 44. Which of the following training topics is mandatory for all personnel who may operate an AST transfer pump? A) Basic first‑aid B) Spill response procedures C) Electrical safety only D) None of the above Answer: B Explanation: Spill response training is required for anyone operating transfer equipment. Question 45. The NEC permits the use of a 250 V, 30 A GFCI breaker to protect a 240 V, 20 A dryer circuit because: A) The breaker’s voltage rating exceeds the circuit voltage B) The breaker’s amperage rating exceeds the circuit load C) Both A and B D) It is not permitted Answer: C Explanation: A higher‑rated GFCI breaker can protect a lower‑rated circuit as long as the breaker’s voltage and amperage ratings are not less than the circuit’s requirements. Question 46. When installing a raceway in a concrete wall, the minimum spacing between supports for EMT is:
A) AFCI is required for all 120 V circuits B) AFCI is optional in commercial occupancies C) AFCI is required only for circuits supplying lighting D) AFCI is not permitted in commercial settings Answer: B Explanation: NEC 210.12(B) makes AFCI protection optional for commercial occupancies. Question 50. The minimum size of a grounding‑electrode conductor for a 400 kVA, 13.8 kV transformer is: A) 2/0 AWG copper B) 4/0 AWG copper C) 250 kcmil aluminum D) 350 kcmil aluminum Answer: B Explanation: NEC Table 250.66 lists 4/0 AWG copper for transformers between 250 kVA and 600 kVA. Question 51. In an AST, the primary purpose of a secondary containment dike is to: A) Provide secondary grounding B) Prevent soil erosion C) Contain a spill that breaches the primary tank wall D) Support the tank structurally Answer: C Explanation: Secondary containment is designed to capture product if the primary tank fails. Question 52. The required frequency for testing an impressed‑current cathodic protection system on an AST is: A) Every 6 months B) Annually C) Every 2 years
D) Every 5 years Answer: B Explanation: Annual testing is mandated for impressed‑current CP systems. Question 53. Which of the following is a permissible method for grounding a metal conduit that serves as the equipment grounding conductor? A) Only at the service entrance B) At each junction box C) At any accessible point using a listed grounding clamp D) No grounding is required if the conduit is continuous Answer: C Explanation: NEC 250.118 allows grounding metal conduit with a listed clamp at any accessible point. Question 54. The NEC requires that a receptacle in a laundry room be GFCI protected if it is: A) Within 6 ft of the washing machine B) Rated 15 A or less C) Located on a dedicated circuit D) All of the above Answer: A Explanation: NEC 210.8(A)(7) mandates GFCI protection for laundry receptacles within 6 ft of the sink or washing machine. Question 55. The maximum allowable temperature rating for conductors in a luminaire listed for 90 °C is: A) 60 °C B) 75 °C C) 90 °C D) 105 °C Answer: C
Question 59. The required minimum size of a grounding‑bonding conductor for a 600 A service is: A) 4 AWG copper B) 2 AWG copper C) 1/0 AWG copper D) 2/0 AWG copper Answer: C Explanation: NEC Table 250.122 lists 1/0 AWG copper for a 600 A service. Question 60. Which of the following is a required element of a written spill‑response plan for an AST facility? A) List of nearby hospitals B) Detailed product inventory C) Step‑by‑step containment procedures D) All of the above Answer: C Explanation: A spill‑response plan must include specific containment and cleanup steps. Question 61. The NEC requires a disconnecting means for a PV array of 10 kW to be located within: A) 5 ft of the array B) 25 ft of the array C) 50 ft of the array D) No distance limitation if the disconnect is labeled “PV disconnect” Answer: B Explanation: NEC 690.13 requires the PV disconnect to be within sight or not more than 25 ft from the array. Question 62. When installing a feeder to a panelboard in a commercial building, the minimum conduit size for three 4/0 AWG copper conductors (including a grounding conductor) is: A) 2 in. EMT B) 2 in. RMC
C) 1 ½ in. EMT D) 1 in. PVC Answer: C Explanation: Box‑fill calculations for three 4/0 AWG conductors require at least 1 ½ in. EMT. Question 63. The primary function of an over‑current protective device (OCPD) on a feeder is to: A) Provide a backup power source B) Limit fault current to a safe level for downstream equipment C) Regulate voltage levels D) Prevent ground‑fault currents only Answer: B Explanation: OCPDs protect conductors and equipment by limiting fault current. Question 64. Which of the following is a permissible method for grounding a metal water pipe that is not in direct contact with the earth? A) Using a ground rod attached to the pipe B) Installing a bonding jumper to the service grounding electrode conductor C) Connecting the pipe to the neutral bus only D) No grounding is required if the pipe is insulated Answer: B Explanation: NEC 250.104(A)(2) permits bonding the pipe to the grounding electrode system via a jumper. Question 65. The required minimum clearance between a 120/240 V panelboard and a combustible wall is: A) 0 in. (directly mounted) B) 1 in. C) 3 in. D) 6 in. Answer: B
