Journeyman Electrician Practice Test 9

Question 1: For a building's metal in-ground support structure to qualify as a grounding electrode, it must be in direct contact with the earth vertically for at least:

• 10 ft
• 8 ft
• 5 ft
• 2 ft

NEC Reference: NEC 250.52(A)(2)

Question 2: A plate electrode must expose at least how much surface area to the exterior soil?

• 1 sq ft
• 2 sq ft
• 4 sq ft
• 9 sq ft

NEC Reference: NEC 250.52(A)(7)

Question 3: A plate electrode must be installed at least how far below the surface of the earth?

• 12 in.
• 18 in.
• 24 in.
• 30 in.

NEC Reference: NEC 250.53(A)(5)

Question 4: A bare aluminum grounding electrode conductor is run on the outside of a building. Which rule applies?

• It must be run in PVC from the meter base to the rod
• It must be buried at least 12 in. below finished grade
• It may lie directly on the soil along the foundation
• It may not touch masonry or earth, or end within 18 in. of earth

NEC Reference: NEC 250.64(A)

Question 5: What is the minimum copper equipment grounding conductor for a branch circuit protected by a 60-ampere breaker?

• 12 AWG
• 10 AWG
• 8 AWG
• 6 AWG

NEC Reference: NEC Table 250.122

Question 6: A 240-volt load draws 24 A over 10 AWG copper conductors. The load is 100 ft from the panel, and the conductor resistance is 1.24 ohms per 1,000 ft. What is the voltage drop?

• 11.9 V
• 7.44 V
• 5.95 V
• 2.98 V

NEC Reference: NEC Chapter 9, Table 8

Question 7: A 10,000 sq ft office area is calculated at the 2023 NEC Table 220.12 unit load. The lighting is a continuous load. What load must the feeder conductors be sized for?

• 13,000 VA
• 16,250 VA
• 35,000 VA
• 43,750 VA

NEC Reference: NEC Table 220.12 and 215.2(A)(1)

Question 8: A load uses 10 kW of true power at a power factor of 0.80. What is its apparent power?

• 8.0 kVA
• 10.0 kVA
• 12.5 kVA
• 18.0 kVA

Question 9: In a dwelling unit, a hallway must have at least one receptacle outlet if it is at least how long?

• 6 ft
• 8 ft
• 10 ft
• 12 ft

NEC Reference: NEC 210.52(H)

Question 10: Underground service conductors (not supplying limited loads) must be at least what size?

• 10 AWG copper or 8 AWG aluminum
• 8 AWG copper or 6 AWG aluminum
• 6 AWG copper or 4 AWG aluminum
• 4 AWG copper or 2 AWG aluminum

NEC Reference: NEC 230.31(B)

Question 11: A feeder supplies 80 A of continuous load and 30 A of noncontinuous load. What is the minimum standard rating of the feeder overcurrent device (not listed for 100% operation)?

• 110 A
• 125 A
• 150 A
• 175 A

NEC Reference: NEC 215.3

Question 12: Article 100 defines "accessible (as applied to wiring methods)" as:

• Removable or exposable without damaging the building finish
• Behind a locked door, with the key kept on the premises
• Within reach from the floor without using a ladder
• Installed in a raceway rather than in a cable assembly

NEC Reference: NEC Article 100

Question 13: Live parts operating at 50 V to 300 V may be guarded against accidental contact by elevating them above the floor or working surface. What is the minimum elevation?

• 7 ft
• 8 ft
• 8½ ft
• 9 ft

NEC Reference: NEC 110.27(A)(4)

Question 14: A 4 Ω resistor is in series with a parallel pair of 6 Ω and 3 Ω resistors. The circuit is connected to 120 V. What is the total current?

• 8.9 A
• 10 A
• 20 A
• 30 A

Question 15: What is the allowable ampacity of a 2/0 AWG aluminum conductor in the 75 °C column of Table 310.16?

• 150 A
• 135 A
• 120 A
• 115 A

NEC Reference: NEC Table 310.16

Question 16: Conductors of a 480Y/277-volt circuit and a 208Y/120-volt circuit share one raceway. What must be true?

• All conductors must be insulated for the highest voltage present
• The raceway must be nonmetallic so that it cannot overheat
• This is never permitted; the circuits need separate raceways
• The 208 V conductors must be run in a separate inner duct

NEC Reference: NEC 300.3(C)(1)

Question 17: Three current-carrying 4/0 AWG THWN copper conductors are installed in a raceway where the ambient temperature is 35 °C. Using the 75 °C column, what is the corrected ampacity?

• 195.5 A
• 202.4 A
• 216.2 A
• 230 A

NEC Reference: NEC Table 310.15(B)(1)(1)

Question 18: Under the 25-foot transformer tap rule, a feeder protected at 300 A supplies a transformer through tap conductors. What is the minimum ampacity of the primary tap conductors?

• 150 A
• 100 A
• 75 A
• 30 A

NEC Reference: NEC 240.21(B)(3)

Question 19: Overcurrent devices must not be located in the vicinity of easily ignitible material. Which location does the NEC give as an example?

• Basements
• Utility rooms
• Garages
• Clothes closets

NEC Reference: NEC 240.24(D)

Question 20: A 10 hp, 230-volt, 3-phase motor is protected by dual-element (time-delay) fuses. What is the maximum fuse size using 430.52 and its first exception?

• 45 A
• 50 A
• 60 A
• 70 A

NEC Reference: NEC Table 430.52 and 430.52(C)(1)

Question 21: A single hermetic refrigerant motor-compressor has a rated-load current of 28 A (the branch-circuit selection current is lower). What minimum ampacity must its branch-circuit conductors have?

• 28 A
• 32.2 A
• 35 A
• 49 A

NEC Reference: NEC 440.32

Question 22: The disconnecting means for an electric sign must generally be located:

• Within sight of the sign
• At the service equipment only
• Inside the sign enclosure only
• At least 50 ft from the sign

NEC Reference: NEC 600.6(A)

Question 23: Supply conductors to a fire pump that pass through a building must be:

• Run in PVC conduit above the suspended ceiling only
• Run in EMT together with the other building feeders
• Run in any wiring method, provided GFPE is installed
• Encased in 2 in. of concrete, or in a listed 2-hour system

NEC Reference: NEC 695.6(A)

Question 24: In a Class I conduit seal, the total cross-sectional area of the conductors may not exceed what percentage of the cross-sectional area of a rigid metal conduit of the same trade size (unless the seal is identified for more)?

• 20%
• 25%
• 31%
• 40%

NEC Reference: NEC 501.15(C)(6)

Question 25: On a construction site, may trees be used to support overhead spans of temporary branch circuits or feeders?

• Yes, if a strain insulator is used at each tree
• Yes, if the tree trunk is at least 6 in. in diameter
• Yes, for spans that are shorter than 50 ft in length
• No; vegetation may not support overhead spans (holiday lights excepted)

NEC Reference: NEC 590.4(J)

Question 26: A lay-in luminaire is installed in a suspended ceiling. How must it be attached?

• Fastened to the ceiling framing by screws, bolts or listed clips
• It may simply rest on the ceiling tiles and grid
• Supported only by its flexible metal conduit whip
• Glued to the ceiling grid with construction adhesive

NEC Reference: NEC 410.36(B)

Question 27: A 4-gang box contains snap switches, and the voltage between two adjacent switches exceeds 300 V. What does the NEC require?

• Identified barriers secured between adjacent switches
• Switches rated at least 30 A, with metal yokes bonded
• A separate single-gang box for each of the switches
• Nothing, if every switch in the box is rated 600 V

NEC Reference: NEC 404.8(B)

Question 28: An angle pull box has one 3 in. conduit and two 2 in. conduits entering the same wall, all with 4 AWG or larger conductors. What is the minimum distance to the opposite wall?

• 28 in.
• 24 in.
• 22 in.
• 18 in.

NEC Reference: NEC 314.28(A)(2)

Question 29: Electrical nonmetallic tubing (ENT) must be securely fastened at intervals not exceeding:

• 3 ft
• 4½ ft
• 6 ft
• 10 ft

NEC Reference: NEC 362.30(A)

Question 30: A 112.5 kVA, 3-phase transformer has a 480-volt delta primary. What is its rated primary line current?

• 78.1 A
• 135.3 A
• 234.4 A
• 312.3 A