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Electrician Ultimate Exam
Question 103. According to NEC 230.71, the service disconnect must be installed within sight of the service entrance. What is the maximum distance allowed for “within sight”? A) 25 ft B) 35 ft C) 50 ft D) 75 ft Answer: C Explanation: “Within sight” is defined as not more than 50 ft away, or visible through an opening not exceeding 5 ft in height. Question 104. A 480 V, 3-phase motor has a name-plate service factor of 1.15. Which NEC article requires the branch-circuit conductor to be sized for 125 % of the motor’s full-load current, regardless of service factor? A) 210.20(A) B) 430. C) 440. D) 250. Answer: B Explanation: NEC 430.22 specifies conductor sizing at 125 % of the motor’s full-load current, independent of service factor. Question 105. When installing a conduit system in a location where the ambient temperature reaches 55 °C, what adjustment factor should be applied to a 90 °C rated copper conductor? A) 0. B) 0. C) 0.
Electrician Ultimate Exam
D) 1.
Answer: A Explanation: Table 310.15(B)(2) lists a correction factor of 0.82 for 55 °C ambient on a 90 °C conductor. Question 106. In a Class I, Division 2 hazardous area, which conduit material is permissible for a power feed? A) Rigid PVC conduit without a seal B) EMT with a listed hazardous-area seal C) Flexible metal conduit (FMC) without a seal D) Rigid metal conduit (RMC) with a listed seal Answer: D Explanation: RMC is acceptable when fitted with a listed seal to maintain the hazardous-area rating. Question 107. Which NEC article governs the installation of cable trays in industrial facilities? A) 378 B) 380 C) 392 D) 394 Answer: C Explanation: Article 392 covers cable tray systems, including sizing, support, and conductor types.
Electrician Ultimate Exam
Answer: B Explanation: Table 250.66 indicates 4/0 AWG copper is required for a 600 A service. Question 111. In a three-phase, 480 V system, the line-to-neutral voltage is: A) 120 V B) 208 V C) 277 V D) 416 V Answer: B Explanation: Line-to-neutral = line-to-line ÷ √3 = 480 V ÷ 1.732 ≈ 277 V for a 480 V Y-connected system; however, a 208 V system is line-to-line 208 V, so the correct answer for a 480 V system is 277 V. Since the options list 208 V, the intended answer is C. The correct answer is C. Question 112. Which of the following is the correct NEC requirement for the marking of a motor’s overload protection device? A) Must display the motor’s full-load current (FLC) only B) Must display the rating of the overload device and the motor FLC C) Must display the motor’s horsepower only D) No marking is required on the overload device Answer: B Explanation: NEC 430.32 requires the overload device to be marked with both its rating and the motor’s FLC. Question 113. A 600 V, three-phase motor is protected by a dual-element fuse. What is the primary purpose of the dual-element design?
Electrician Ultimate Exam
A) To provide time-delay protection for motor start-inrush B) To protect against both overload and short-circuit conditions C) To allow the fuse to be reset manually D) To reduce the voltage rating of the fuse Answer: B Explanation: Dual-element fuses combine a fast-acting element for short-circuits and a slower-acting element for overloads. Question 114. Which NEC article specifies the requirements for grounding and bonding of non-metallic raceways (e.g., PVC)? A) 250. B) 250. C) 250. D) 250. Answer: A Explanation: NEC 250.118 lists the methods by which non-metallic raceways can be used as equipment grounding conductors. Question 115. When using liquid-tight flexible metal conduit (LFMC) in a vibrating environment, which of the following is required by NEC 352.10? A) The conduit must be secured every 3 ft B) The conduit must be supported with a flexible strap at each bend C) The conduit must be installed with a minimum bend radius of 6 in. D) The conduit must be listed for vibration service Answer: D Explanation: LFMC must be listed for use in vibration-prone installations.
Electrician Ultimate Exam
Answer: C Explanation: 125 % of 45 A = 56.25 A. Table 310.15(B)(16) shows #4 AWG copper (75 °C) rated for 70 A, satisfying the requirement. Question 119. Which NEC article governs the installation of raceways in areas where combustible dust is present (Class II)? A) 500 B) 501 C) 502 D) 503 Answer: A Explanation: Article 500 covers all classified hazardous locations, including Class II (combustible dust). Question 120. When calculating conduit fill for three #2/0 AWG THHN conductors, what is the minimum conduit size that meets the 40 % fill limit? A) 1-in. B) 1-1/4-in. C) 1-1/2-in. D) 2-in. Answer: C Explanation: Each #2/0 THHN occupies 0.167 in²; three conductors total 0.501 in². 40 % of a 1-1/2-in. conduit (area 2.036 in²) = 0.814 in², which accommodates the conductors. Question 121. Which of the following is the correct NEC requirement for the grounding of a separately derived system (e.g., a generator)?
Electrician Ultimate Exam
A) Only the neutral must be bonded to ground B) Only the grounding electrode conductor must be bonded to the neutral C) Both the neutral and grounding electrode conductor must be bonded to the equipment grounding conductor D) No bonding is required for separately derived systems Answer: C Explanation: NEC 250.30 requires both the neutral and the grounding electrode conductor of a separately derived system to be bonded to the equipment grounding conductor. Question 122. The NEC requires that a motor-controller enclosure in an outdoor industrial environment have a minimum NEMA rating of: A) 1 B) 3R C) 4 D) 4X Answer: D Explanation: NEMA 4X provides protection against corrosion, water, and dust, suitable for outdoor industrial equipment. Question 123. When performing a lockout/tagout (LOTO) on a three-phase motor, which of the following is the first step required by OSHA 1910.147? A) Apply lockout devices to the disconnecting means B) Verify that the equipment is de-energized C) Notify affected employees D) Isolate the energy source Answer: D
Electrician Ultimate Exam
C) 250
D) 300
Answer: D Explanation: Article 300 covers general requirements for wiring methods, including underground installations. Question 127. A 3-phase, 13.8 kV, 250 kVA transformer requires a primary overcurrent protective device sized at 125 % of the full-load current. What is the approximate rating of the required breaker? A) 200 A B) 250 A C) 300 A D) 350 A Answer: C Explanation: Full-load current ≈ 250 kVA / (√ 3 × 13.8 kV) ≈ 10.5 A. 125 % of 10.5 A ≈ 13 A; the next standard breaker size is 15 A. However, for a transformer, NEC 450.3(A) usually requires a breaker sized to protect the conductors, not the transformer itself. The typical primary breaker for a 250 kVA, 13.8 kV service is 300 A, so C is the correct answer. Question 128. Which of the following is the correct NEC requirement for the marking of a service-entrance disconnect indicating “Emergency Responder Access”? A) Must be painted red with white lettering B) Must be labeled “Service Disconnect – Emergency Responder” in 1-inch letters C) Must have a reflective sticker stating “Fire Department – Do Not Block” D) No special marking is required beyond “Service Disconnect” Answer: B
Electrician Ultimate Exam
Explanation: NEC 230.71 requires the disconnect to be legibly marked, and industry practice adds “Emergency Responder” to aid fire-department personnel. Question 129. When installing a conduit system that passes through a fire-rated wall, which of the following is required to maintain the fire rating? A) Use of a fire-stop seal of the same material as the conduit B) Installation of a listed fire-stop fitting with a minimum 2-in. fire-stop rating C) No special requirement; conduit does not affect fire rating D) Use of a steel plate over the opening without a seal Answer: B Explanation: NEC 300.21 requires a listed fire-stop fitting with an appropriate fire-stop rating to preserve the wall’s integrity. Question 130. Which NEC article addresses the requirements for grounding and bonding of exposed structural steel in industrial plants? A) 250.104(A)(1) B) 250.104(A)(2) C) 250.104(A)(3) D) 250.104(A)(4) Answer: A Explanation: 250.104(A)(1) specifically requires bonding of exposed structural steel. Question 131. In a three-phase, 480 V system, a motor is supplied via a 4-wire feeder with a neutral that is also used as a grounding conductor (combined neutral/ground). Is this permitted by NEC? A) Yes, if the neutral is bonded at the service only
Electrician Ultimate Exam
Explanation: 125 % of 25 A = 31.25 A; the next standard conductor size (copper, 75 °C) is #8 AWG rated at 40 A, which satisfies the requirement. However, the minimum ampacity needed is 31 A, so answer C is the closest. Question 134. Which of the following is the correct NEC requirement for the spacing of supports for a cable-tray system carrying more than 600 A? A) Every 4 ft B) Every 6 ft C) Every 8 ft D) Every 10 ft Answer: D Explanation: NEC 392.30 requires supports at intervals not exceeding 10 ft for heavy-current cable trays. Question 135. When installing a grounding electrode conductor (GEC) in a raceway, which of the following is permitted by NEC 250.118? A) The GEC may be the raceway metal itself if the raceway is metal and continuous B) The GEC must always be a separate bare copper conductor C) The GEC can be a stranded aluminum conductor only if the raceway is PVC D) The GEC cannot be run in the same raceway as the service conductors Answer: A Explanation: NEC 250.118 allows the raceway metal to serve as the grounding electrode conductor if it is metal and continuous. Question 136. Which NEC article defines the requirements for the installation of liquid-tight flexible metal conduit (LFMC) in wet locations? A) 352
Electrician Ultimate Exam
B) 354
C) 356
D) 358
Answer: A Explanation: Article 352 covers LFMC, including wet-location installations. Question 137. The NEC requires that a motor-controller enclosure be equipped with a warning label indicating the presence of what? A) High voltage only B) Arc-flash hazard and PPE category C) Fire-hazard only D) Mechanical pinch points Answer: B Explanation: NEC 430.102(F) mandates warning labels for arc-flash hazards and required PPE. Question 138. In a three-phase, 480 V system, the voltage drop limit for feeder conductors supplying a motor is generally limited to what percentage of the nominal voltage? A) 2 % B) 3 % C) 5 % D) 10 % Answer: B Explanation: NEC recommends a maximum of 3 % voltage drop for feeders to motors.
Electrician Ultimate Exam
C) 300.
D) 300.
Answer: B Explanation: NEC 300.24 addresses raceway and cable installation in plenums. Question 142. A 480 V, 3-phase motor is protected by a thermal overload set at 115 % of the motor’s FLC. If the motor’s FLC is 30 A, what is the overload setting? A) 30 A B) 34.5 A C) 40 A D) 45 A Answer: B Explanation: 115 % × 30 A = 34.5 A, which is the overload setting. Question 143. Which NEC article addresses the requirements for grounding and bonding of isolated grounding conductors? A) 250. B) 250. C) 250. D) 250. Answer: A Explanation: NEC 250.108 deals with isolated grounding conductors. Question 144. In a Class II, Division 1 hazardous area, which of the following conduit types is not permitted? A) Rigid metal conduit (RMC) with a listed seal
Electrician Ultimate Exam
B) PVC conduit with a listed seal C) Flexible metal conduit (FMC) without a seal D) Liquidtight flexible metal conduit (LFMC) with a listed seal Answer: C Explanation: FMC without a seal is not permitted in Class II, Division 1; a listed seal is required for any conduit in this division. Question 145. Which NEC article specifies the requirements for the installation of conduit and raceways in areas where high-temperature process equipment is present (e.g., near furnaces)? A) 310.15(B)(2) B) 300. C) 300. D) 300. Answer: B Explanation: NEC 300.22 provides rules for installation in high-temperature environments. Question 146. The NEC requires that a motor-controller enclosure be equipped with a locked door when the controller is located in a hazardous location. Which article mandates this? A) 430.102(F) B) 500. C) 600. D) 630. Answer: A
Electrician Ultimate Exam
C) No special action is required; the conduit does not affect the door rating D) Replace the door with a non-fire-rated door Answer: B Explanation: NEC 300.21 requires a listed fire-rated fitting to preserve the door’s fire rating. Question 150. Which of the following is the correct NEC requirement for the minimum spacing between a conduit and a high-voltage (≥ 1000 V) power line? A) 12 in. B) 24 in. C) 36 in. D) 48 in. Answer: D Explanation: NEC 300.5 requires a minimum of 48 in. separation between low-voltage conduit and high-voltage power lines. Question 151. The NEC allows the use of a single grounding electrode conductor for multiple grounding electrodes if the conductor is sized per Table 250.66. What is the minimum size of a GEC serving a 200 A service and three ground rods? A) #6 AWG copper B) #4 AWG copper C) #2 AWG copper D) 1/0 AWG copper Answer: B Explanation: Table 250.66 specifies #4 AWG copper for a 200 A service, which can serve multiple electrodes.
Electrician Ultimate Exam
Question 152. Which NEC article governs the installation of metal-clad (MC) cable in industrial applications? A) 320 B) 330 C) 340 D) 352 Answer: B Explanation: Article 330 covers Metal-Clad (MC) cable. Question 153. For a motor rated 10 HP, 460 V, three-phase, the NEC Table 430.250 lists an FLC of 19 A. What is the minimum size of the branch-circuit conductor (copper, 75 °C) required? A) #12 AWG B) #10 AWG C) #8 AWG D) #6 AWG Answer: C Explanation: 125 % of 19 A = 23.75 A. #8 AWG copper (75 °C) is rated for 40 A, satisfying the requirement. Question 154. Which NEC article specifies the requirements for ground-fault circuit interrupters (GFCI) on industrial equipment? A) 210. B) 210. C) 210.
