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ELECTRICIAN 2014 Ultimate Exam
Question 1. What is the correct formula to calculate the current (I) in a single-phase AC circuit when voltage (V) and resistance (R) are known? A) I = V × R B) I = V ÷ R C) I = R ÷ V D) I = √(V² – R²) Answer: B Explanation: Ohm’s Law states I = V / R, dividing voltage by resistance gives the current. Question 2. If a sign’s power rating is 150 W and it is supplied from a 120 V AC source, what is the current draw? A) 0.8 A B) 1.25 A C) 2.0 A D) 3.0 A Answer: B Explanation: I = P / V = 150 W ÷ 120 V = 1.25 A. Question 3. Which NEC article specifically governs electric signs and outline lighting? A) Article 250 B) Article 310 C) Article 600 D) Article 800 Answer: C Explanation: NEC Article 600 contains the requirements for electric signs and outline lighting.
ELECTRICIAN 2014 Ultimate Exam
Question 4. According to NEC 600.4, what is the minimum ampacity for a branch circuit that supplies a sign outlet? A) 15 A B) 20 A C) 30 A D) 40 A Answer: B Explanation: NEC 600.4 requires a minimum 20-amp branch circuit for sign outlets. Question 5. When installing a neon sign, which of the following is the maximum permissible secondary-circuit voltage for a transformer listed for use with neon? A) 120 V B) 240 V C) 600 V D) 1,500 V Answer: C Explanation: Neon transformers are typically limited to 600 V secondary to prevent arcing and meet NEC limits. Question 6. A Class 2 power supply for LED signage is limited to which maximum output voltage? A) 30 V B) 50 V C) 100 V D) 150 V Answer: C Explanation: NEC 725 defines Class 2 circuits as limited to 100 V (or 150 V DC for certain applications) to restrict fire hazard. Question 7. Which of the following is the primary purpose of a bonding jumper on a metal sign structure?
ELECTRICIAN 2014 Ultimate Exam
B) 29 CFR 1926.
C) 29 CFR 1910.
D) 29 CFR 1926.
Answer: B Explanation: OSHA 29 CFR 1926.501 requires fall protection for construction activities on scaffolds. Question 11. If a sign’s LED driver is rated for 24 VDC output and 3 A, what is the maximum power it can deliver? A) 48 W B) 72 W C) 96 W D) 120 W Answer: B Explanation: Power = V × I = 24 V × 3 A = 72 W. Question 12. Which of the following materials is NOT permitted for use as a raceway in a wet location? A) Rigid metal conduit (RMC) B) PVC conduit C) EMT (electrical metallic tubing) D) Liquid-tight flexible metal conduit (LFMC) Answer: C Explanation: EMT is not rated for wet locations unless specifically listed; RMC, PVC, and LFMC are permitted. Question 13. When calculating voltage drop for a 150-ft run of 12-AWG copper conductors feeding a low-voltage LED sign, which factor is most critical? A) Conductor insulation type B) Load current C) Ambient temperature
ELECTRICIAN 2014 Ultimate Exam
D) Number of conductors in the conduit Answer: B Explanation: Voltage drop is directly proportional to load current; the longer the run and higher the current, the greater the drop. Question 14. NEC 250.118 defines a “grounding electrode system.” Which of the following is NOT considered a grounding electrode? A) Concrete-encased electrode (Ufer) B) Metal underground water pipe C) Isolated metal sign frame not bonded to the building D) Ground rod Answer: C Explanation: An isolated metal sign frame is not a grounding electrode unless bonded to the system. Question 15. What is the primary function of a disconnecting means for an electric sign according to NEC 600.7? A) To provide over-current protection B) To allow rapid removal of the sign for maintenance C) To isolate the sign’s circuit from the supply for service or emergency D) To convert AC to DC power Answer: C Explanation: A disconnecting means must be readily accessible to isolate the sign circuit for service or emergency. Question 16. A sign is mounted 6 ft above a combustible roof material. According to NEC 600.21, what is the minimum required clearance? A) 3 ft B) 6 ft C) 8 ft D) 10 ft
ELECTRICIAN 2014 Ultimate Exam
Explanation: NEC Chapter 4 (Grounding and Bonding) covers all grounding requirements. Question 20. A sign’s LED driver is listed as “UL 1998.” What does this listing indicate? A) The driver meets fire-resistance standards for high-rise buildings B) The driver is approved for use in hazardous (Class I) locations C) The driver complies with UL’s safety standards for low-voltage lighting products D) The driver is certified for solar-powered operation only Answer: C Explanation: UL 1998 is the standard for low-voltage lighting products, ensuring safety and performance. Question 21. During a lockout/tagout (LOTO) procedure, which of the following actions is required before working on a sign’s electrical system? A) Verify that the sign is still illuminated B) Place a “danger” tag on the nearest ladder C) De-energize the circuit and apply a lock and tag to the disconnecting means D) Notify the building’s tenants of the work schedule only Answer: C Explanation: LOTO requires de-energizing the circuit and securing the disconnect with a lock and tag to prevent accidental re-energization. Question 22. What is the minimum size (in AWG) for a grounding electrode conductor (GEC) attached to a 100-A service? A) #12 AWG B) #10 AWG C) #8 AWG D) #6 AWG Answer: C Explanation: NEC Table 250.66 specifies #8 AWG copper for a 100-A service.
ELECTRICIAN 2014 Ultimate Exam
Question 23. Which of the following best describes the term “class 2 circuit” as defined by NEC 725? A) A circuit limited to 30 V and 1 A B) A circuit limited to 150 V and 2 A C) A circuit limited to 100 V (or 150 V DC) and 5 A, with a power limit of 100 W D) A circuit without any voltage limitation Answer: C Explanation: Class 2 circuits are limited to 100 V (or 150 V DC) and 5 A, and cannot exceed 100 W. Question 24. A sign is installed on a building with a metal roof. According to NEC 600.21, what is the required clearance between the sign and the roof when the roof is classified as “non-combustible”? A) 0 ft (no clearance) B) 1 ft C) 3 ft D) 6 ft Answer: A Explanation: When the roof material is non-combustible, NEC does not require a separation clearance. Question 25. Which of the following statements about series-wired sign modules is correct? A) Voltage across each module is the same as the source voltage. B) Current through each module is the same, but voltage divides among them. C) Both voltage and current are identical across each module. D) Series wiring is prohibited for LED signage. Answer: B Explanation: In a series circuit, the same current flows through each component, while the voltage divides proportionally to the impedance of each module.
ELECTRICIAN 2014 Ultimate Exam
A) A metal water pipe that is not bonded to the grounding electrode system B) A concrete-encased electrode (Ufer) that is at least 20 ft long C) A copper pipe used solely for gas distribution D) An isolated metal sign frame Answer: B Explanation: A concrete-encased electrode meeting length requirements is an effective grounding electrode. Question 30. If a sign’s total load is 2 kVA and the power factor is 0.8 lagging, what is the apparent current drawn from a 208 V three-phase supply? A) 5.5 A B) 8.8 A C) 10.5 A D) 14.0 A Answer: B Explanation: Apparent power S = 2 kVA. Line current I = S / (√3 × V) = 2000 VA ÷ (1.732 × 208 V) ≈ 5.55 A per phase. Because the load is three-phase, the current per phase is 5.5 A; however, the question asks for total line current, which is 5.5 A. The closest answer is B (8.8 A) – but the correct calculation yields 5.5 A, indicating a typo in answer choices. The intended correct answer is A (5.5 A). Corrected Answer: A Explanation: Using S = √3 × V × I, I = S/(√3 × V) = 2000 VA/(1.732 × 208 V) ≈ 5.5 A. Question 31. Which NEC article governs the installation of wiring methods for signs in hazardous (Class I) locations? A) Article 400 B) Article 500 C) Article 600 D) Article 760 Answer: B
ELECTRICIAN 2014 Ultimate Exam
Explanation: NEC Article 500 covers hazardous (Class I, II, III) locations, including wiring methods. Question 32. When using a transformer to step down 120 V to 24 V for an LED sign, what is the maximum permissible secondary voltage per NEC 600.4(A)? A) 30 V B) 60 V C) 100 V D) 150 V Answer: B Explanation: NEC 600.4(A) limits the secondary voltage of sign transformers to 60 V. Question 33. A sign’s metallic frame is attached to a concrete foundation using expansion anchors. Which of the following testing methods confirms proper anchor installation? A) Visual inspection only B) Torque test to manufacturer’s specified torque value C) Pull-out test to 50 % of the anchor’s rated load D) Magnetic field measurement Answer: B Explanation: Expansion anchors are verified by applying the specified torque to ensure proper embedment. Question 34. Which of the following is a required labeling practice for a sign’s disconnecting means? A) Only the sign owner’s name is required. B) The label must indicate “Disconnect” and the sign identification number. C) No labeling is needed if the sign is less than 5 ft². D) A red “danger” tag is sufficient. Answer: B Explanation: NEC 600.7 requires the disconnect to be clearly labeled with “Disconnect” and the sign’s identification.
ELECTRICIAN 2014 Ultimate Exam
A) Three-phase delta connection B) Ground fault indicator C) Neon transformer primary D) LED driver input Answer: A Explanation: The delta (Δ) symbol denotes a three-phase delta connection. Question 38. Which of the following is the correct method for supporting a high-voltage GTO cable in a neon sign? A) Attach directly to the sign’s metal frame with no supports. B) Use insulated cable trays rated for the voltage and temperature. C) Suspend with non-metallic rope only. D) Run the cable through PVC conduit without any supports. Answer: B Explanation: High-voltage GTO cable must be supported on insulated trays or conduit rated for its voltage and temperature. Question 39. What is the minimum clearance required between a sign’s high-voltage wiring and a combustible roof surface? A) 1 ft B) 3 ft C) 6 ft D) 10 ft Answer: C Explanation: NEC 600.21 requires a minimum 6-ft clearance from combustible materials for high-voltage sign wiring. Question 40. When a sign’s power supply is listed for “NEMA 3R” enclosure, what does this rating signify? A) Indoor use only, no protection against moisture. B) Outdoor use, protection against rain, sleet, and snow.
ELECTRICIAN 2014 Ultimate Exam
C) Heavy-duty industrial use with oil-resistant housing. D) Explosion-proof enclosure for hazardous locations. Answer: B Explanation: NEMA 3R enclosures are rated for outdoor use, protecting against rain, sleet, and snow. Question 41. Which NEC table provides the ampacity adjustments for conductors in conduit with ambient temperatures above 30 °C? A) Table 310. B) Table 310.15(B)(2)(a) C) Table 310. D) Table 310.3(B) Answer: B Explanation: NEC Table 310.15(B)(2)(a) gives temperature correction factors for conductors in raceways. Question 42. A sign’s LED driver is installed in a wet location. Which of the following mounting methods complies with NEC? A) Mounted directly on a metal sign frame without a cover. B) Placed in a listed weatherproof enclosure with a gasketed cover. C) Suspended from a non-conductive chain without any enclosure. D) Installed inside a standard drywall box. Answer: B Explanation: NEC requires wet-location equipment to be placed in a listed weatherproof enclosure. Question 43. Which of the following is the correct definition of “effective grounding electrode system” per NEC 250.53? A) Any metal pipe that touches the earth. B) Grounding electrode conductors that are bonded together at a single point. C) A system that provides a low-impedance path to earth, such as a Ufer electrode, ground rod, or metal water pipe bonded to the system.
ELECTRICIAN 2014 Ultimate Exam
Answer: B Explanation: A ballast regulates current and provides the high voltage needed to strike a fluorescent lamp. Question 47. When calculating the total load for a sign with multiple LED modules, which of the following is the correct approach? A) Add the voltage of each module together. B) Add the current of each module together, then multiply by the system voltage. C) Multiply the number of modules by the wattage of one module. D) Use the highest-rated module’s wattage as the total load. Answer: B Explanation: Total current is the sum of each module’s current; total power is then calculated by multiplying total current by system voltage. Question 48. According to OSHA 29 CFR 1926.502, what is the minimum required personal protective equipment (PPE) when working on an energized sign? A) Hard hat only B) Insulated gloves, safety glasses, and flame-resistant clothing C) Steel-toe boots and hearing protection D) No PPE required if the voltage is below 50 V Answer: B Explanation: OSHA requires insulated gloves, eye protection, and flame-resistant clothing when working on energized equipment. Question 49. A sign’s foundation requires a concrete mix with a minimum compressive strength of 4,000 psi. Which of the following water-to-cement ratios is most appropriate? A) 0. B) 0. C) 0. D) 0. Answer: A
ELECTRICIAN 2014 Ultimate Exam
Explanation: Lower water-to-cement ratios (≈0.55) yield higher compressive strength, suitable for 4,000 psi requirements. Question 50. Which NEC article governs the installation of raceways in exposed outdoor locations? A) Article 300 B) Article 310 C) Article 352 D) Article 358 Answer: D Explanation: NEC Article 358 covers liquid-tight flexible metal conduit, commonly used outdoors. Question 51. When selecting a conduit size for three #8 AWG THHN conductors and one #10 AWG grounding conductor, which conduit diameter meets the 40 % fill requirement? A) ½-in. EMT B) ¾-in. EMT C) 1-in. EMT D) 1-¼-in. EMT Answer: B Explanation: Using Table 1, the total cross-sectional area fits within 40 % of a ¾-in. EMT’s capacity. Question 52. What is the primary reason for separating Class 2 low-voltage wiring from power wiring in a sign installation? A) To simplify routing B) To reduce electromagnetic interference and meet NEC separation requirements C) To allow higher current in the low-voltage circuit D) To meet aesthetic standards Answer: B
ELECTRICIAN 2014 Ultimate Exam
Question 56. When a sign uses a high-voltage transformer with a secondary voltage of 600 V, what is the required minimum clearance to a non-grounded metal pipe according to NEC 600.21? A) 2 ft B) 3 ft C) 5 ft D) 10 ft Answer: C Explanation: NEC 600.21 mandates a minimum 5-ft clearance from high-voltage secondary conductors to combustible or ungrounded metal parts. Question 57. Which of the following is the correct procedure for testing continuity of a grounding electrode conductor? A) Use a megohmmeter to measure resistance to earth. B) Perform a low-impedance voltage tester (LEVT) test between the GEC and a known ground. C) Apply a continuity tester between the GEC and the neutral bus. D) No testing is required if the conductor is copper. Answer: B Explanation: A LEVT test verifies low-impedance continuity between the grounding conductor and the earth ground. Question 58. A sign’s structural steel is fabricated from ASTM A36. Which of the following properties is correct for this material? A) Minimum yield strength of 36,000 psi B) Minimum tensile strength of 58,000 psi C) Minimum elongation of 20 % D) All of the above Answer: D Explanation: ASTM A36 steel has a minimum yield strength of 36 ksi, tensile strength of 58–80 ksi, and ≥20 % elongation.
ELECTRICIAN 2014 Ultimate Exam
Question 59. Which NEC provision requires that all sign components be listed by a recognized testing laboratory? A) 600.4(A) B) 600.6(A) C) 600.8(A) D) 600.10(A) Answer: B Explanation: NEC 600.6(A) states that signs and sign components must be listed. Question 60. When performing a voltage-drop calculation for a 120-V AC sign circuit drawing 15 A over a 100-ft run using 10-AWG copper, what is the approximate voltage drop? A) 1.5 V B) 3.0 V C) 4.5 V D) 6.0 V Answer: B Explanation: Resistance of 10-AWG ≈ 1.0 Ω per 1000 ft. Loop length = 200 ft, R = 0.2 Ω. Voltage drop = 15 A × 0.2 Ω = 3.0 V. Question 61. Which OSHA standard addresses the use of personal fall arrest systems when working from aerial lifts on sign installations? A) 29 CFR 1910. B) 29 CFR 1926.502(d) C) 29 CFR 1926.1053(b)(2) D) 29 CFR 1910.147(b)(4) Answer: B Explanation: OSHA 1926.502(d) specifies requirements for personal fall arrest systems on aerial lifts.
