Journeyman Electrician Practice Test 12

Question 1: A 75 kVA transformer (a separately derived system) has 250 kcmil copper secondary conductors. What is the minimum copper grounding electrode conductor for the secondary?

• 3/0 AWG
• 1/0 AWG
• 2 AWG
• 4 AWG

NEC Reference: NEC 250.30(A)(5) and Table 250.66

Question 2: A run of metal conduit includes an expansion fitting. How must electrical continuity be maintained across the fitting?

• With an equipment bonding jumper or other approved means
• Continuity is not required at expansion fittings
• It is maintained by the fitting alone
• By filling the fitting with conductive grease

NEC Reference: NEC 250.98

Question 3: A building has a lightning protection system with its own ground terminals. What does the NEC require?

• Bond its ground terminals to the building grounding electrode system
• Keep it completely isolated from the electrical system
• Connect it to the neutral in each panelboard
• Use it as the only grounding electrode for the service

NEC Reference: NEC 250.106

Question 4: Exposed metal parts of fixed equipment supplied by a wiring method that includes an EGC must be connected to the EGC when they are within what distance of ground or grounded metal and subject to contact?

• 5 ft vertically or 3 ft horizontally
• 8 ft vertically or 5 ft horizontally
• 10 ft vertically or 6 ft horizontally
• 12 ft vertically or 8 ft horizontally

NEC Reference: NEC 250.110

Question 5: A new branch circuit is installed for an electric clothes dryer. How must the dryer frame be grounded?

• By a separate ground rod at the dryer
• By the neutral, using a 3-wire cord and receptacle
• By the metal water pipe behind the dryer
• By an equipment grounding conductor, using a 4-wire circuit

NEC Reference: NEC 250.140

Question 6: A 208-volt, 3-phase feeder carries 50 A to a panel 200 ft away. It uses 6 AWG copper (26,240 cmil, K = 12.9). What is the voltage drop?

• 14.7 V
• 9.8 V
• 8.5 V
• 4.9 V

NEC Reference: NEC Chapter 9, Table 8

Question 7: A duplex dwelling has two 12 kW household electric ranges on one feeder. What is the demand load for the ranges?

• 8 kW
• 11 kW
• 16 kW
• 24 kW

NEC Reference: NEC Table 220.55, Column C

Question 8: A 10 Ω and a 30 Ω resistor are connected in series across 120 V. What total power do they use?

• 1,920 W
• 480 W
• 360 W
• 120 W

Question 9: For the dwelling receptacle spacing rule, what is the minimum width of a "wall space" that must be counted?

• 1 ft
• 2 ft
• 3 ft
• 4 ft

NEC Reference: NEC 210.52(A)(2)

Question 10: In an office building (not a one- or two-family dwelling), indoor service equipment must have a 125-volt, 15- or 20-ampere receptacle outlet within what distance?

• 6 ft
• 10 ft
• 25 ft
• 50 ft

NEC Reference: NEC 210.63(B)(1)

Question 11: Service-entrance conductors have an ampacity of 190 A. There is one service disconnect. What is the largest standard service overcurrent device permitted?

• 175 A
• 190 A
• 200 A
• 225 A

NEC Reference: NEC 230.90(A)

Question 12: Equipment rated 400 A has terminals not otherwise marked. What temperature rating may be used for conductor ampacity at these terminals?

• 60 °C
• 75 °C
• 90 °C
• 105 °C

NEC Reference: NEC 110.14(C)(1)(b)

Question 13: Which enclosure type is commonly used outdoors to protect against rain, sleet and snow?

• Type 3R
• Type 1
• Type 12
• Type 7

NEC Reference: NEC Table 110.28

Question 14: A series circuit has 8 Ω of resistance and 6 Ω of inductive reactance, connected to 120 V AC. What is the current?

• 8.6 A
• 10 A
• 12 A
• 15 A

Question 15: Several NM cables enter the top of a surface-mounted panelboard through a short nonflexible raceway (instead of individual connectors). What length of raceway is permitted?

• 2 ft to 25 ft
• 18 in. to 10 ft
• 12 in. to 6 ft
• 6 in. to 3 ft

NEC Reference: NEC 312.5(C) Exception

Question 16: When counting current-carrying conductors in a raceway for ampacity adjustment, how is the equipment grounding conductor counted?

• It counts as one conductor
• It counts only if insulated
• It counts as one-half conductor
• It is not counted

NEC Reference: NEC 310.15(F)

Question 17: Type MC cable feeding a luminaire in an accessible ceiling may be unsupported for up to what length from the last point where it is securely fastened?

• 3 ft
• 4½ ft
• 6 ft
• 10 ft

NEC Reference: NEC 330.30(D)(2)

Question 18: Secondary conductors may be protected by the overcurrent device on the primary side of a transformer (with the ratio limit applied) when the transformer has:

• A single-phase, 2-wire (single-voltage) secondary
• Any secondary, if the primary is fused
• A 120/240-volt, 3-wire single-phase secondary
• A 208Y/120-volt, 4-wire wye secondary

NEC Reference: NEC 240.4(F)

Question 19: On a 20-ampere branch circuit, 18 AWG fixture wire may be used as a tap to a luminaire if its run length does not exceed:

• 100 ft
• 50 ft
• 25 ft
• 6 ft

NEC Reference: NEC 240.5(B)(2)

Question 20: A variable-frequency drive (power conversion equipment) has a rated input current of 40 A. What minimum ampacity must its supply conductors have?

• 40 A
• 46 A
• 50 A
• 60 A

NEC Reference: NEC 430.122(A)

Question 21: What is the maximum dual-element (time-delay) fuse rating for a 3 hp, 230-volt, single-phase motor, using 430.52 and its first exception?

• 25 A
• 30 A
• 35 A
• 45 A

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

Question 22: A junction box connected to the conduit for a wet-niche pool luminaire must be located at least how far from the inside wall of the pool (unless separated by a fence or wall)?

• 18 in.
• 3 ft
• 4 ft
• 6 ft

NEC Reference: NEC 680.24(A)(2)

Question 23: How must emergency lighting be arranged?

• So every emergency luminaire is on one circuit
• So the occupants can switch it on when needed
• So it operates only while the fire alarm sounds
• So one failed lamp can't leave an area totally dark

NEC Reference: NEC 700.16(A)

Question 24: In a hospital wet procedure location, how must receptacles and fixed equipment be protected against shock?

• Isolated power, or Class A GFCI-level tripping
• No special shock protection
• Surge-protective devices only
• AFCI protection on every circuit

NEC Reference: NEC 517.20(A)

Question 25: In an aircraft hangar, the entire floor area (and adjacent areas not suitably separated) is classified as Class I, Division 2 up to what height above the floor?

• 5 ft
• 18 in.
• 12 in.
• 6 in.

NEC Reference: NEC 513.3(C)(1)

Question 26: A single section of lighting track 4 ft long or shorter must have at least how many supports?

• One
• Four
• Three
• Two

NEC Reference: NEC 410.155(B)

Question 27: Metal faceplates for receptacles made of ferrous metal must be at least how thick?

• 0.020 in.
• 0.030 in.
• 0.040 in.
• 0.060 in.

NEC Reference: NEC 406.6(A)

Question 28: A metal box will contain eight 10 AWG current-carrying conductors, two 10 AWG EGCs, one receptacle and internal clamps. Which is the smallest standard box that will work?

• 4 in. × 1½ in. square (21.0 cu in.)
• 4-11/16 in. × 1½ in. square (29.5 cu in.)
• 4 in. × 2-1/8 in. square (30.3 cu in.)
• 4-11/16 in. × 2-1/8 in. square (42.0 cu in.)

NEC Reference: NEC 314.16(A) and (B)

Question 29: Service conductors buried 18 in. or more below grade (not under the utility's exclusive control) must have a warning ribbon placed at least how far above them?

• 6 in.
• 12 in.
• 18 in.
• 24 in.

NEC Reference: NEC 300.5(D)(3)

Question 30: The doorway of an oil-insulated transformer vault must have a sill or curb high enough to confine the oil of the largest transformer, and in no case less than:

• 12 in.
• 6 in.
• 4 in.
• 2 in.

NEC Reference: NEC 450.43(B)