Journeyman Electrician Practice Test 27

Question 1: How many 8 AWG conductors may be installed in a 4 in. × 1½ in. square metal box (21.0 cu in.) with no devices or fittings?

• 4
• 6
• 7
• 9

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

Question 2: A conduit body (not a short-radius type) encloses 6 AWG and smaller conductors. What must its cross-sectional area be?

• Twice the largest conduit's area
• At least 12 cu in. in every case
• Three times the largest conduit's area
• Equal to the largest conduit attached

NEC Reference: NEC 314.16(C)(1)

Question 3: What is the maximum total of bends permitted in a run of flexible metal conduit (FMC) between pull points?

• 360°
• 270°
• 180°
• 90°

NEC Reference: NEC 348.26

Question 4: Several motors on one feeder never all run at the same time. May the feeder conductors be smaller than 430.24 requires?

• Yes, if the AHJ grants permission
• Only for motors under 1 hp
• Yes, always reduced by 50%
• No, never under any condition

NEC Reference: NEC 430.26

Question 5: In a panelboard on a 3-phase, 4-wire delta system (with a high leg), which bus phase must the high leg be connected to?

• C phase
• A phase
• Any phase, if marked orange
• B phase

NEC Reference: NEC 408.3(E)(1)

Question 6: What is the maximum length of the flexible supply cord for a 120-volt room air conditioner?

• 15 ft
• 10 ft
• 8 ft
• 6 ft

NEC Reference: NEC 440.64

Question 7: Amusement rides must be kept at least how far in any direction from overhead conductors operating at 600 V or less (other than the conductors supplying the ride)?

• 8 ft
• 12 ft
• 15 ft
• 20 ft

NEC Reference: NEC 525.5(B)

Question 8: As the temperature of a copper conductor increases, its resistance:

• Decreases
• Remains constant
• Drops to zero
• Increases

Question 9: In a mobile home park calculation, what is the minimum load per mobile home lot before demand factors are applied?

• 10,000 VA
• 16,000 VA
• 18,000 VA
• 20,000 VA

NEC Reference: NEC 550.31(1)

Question 10: When the supply frequency decreases, what happens to capacitive reactance (XC)?

• It decreases
• It increases
• It remains constant
• It becomes zero

Question 11: Per NEC Table 314.16(B), what is the volume allowance per conductor for No. 10 AWG wire?

• 2.25 cubic inches
• 2.50 cubic inches
• 3.00 cubic inches
• 2.00 cubic inches

NEC Reference: NEC Table 314.16(B)

Question 12: A metal box has 18.0 cubic inches of volume. Using No. 12 AWG conductors only (2.25 cubic inches each), how many conductors can fit if there is also one receptacle device installed?

• 8 conductors
• 6 conductors
• 4 conductors
• 10 conductors

NEC Reference: NEC 314.16(B)

Question 13: Per NEC 440.64, what is the maximum flexible cord length for a 208-volt or 240-volt room air conditioner?

• 6 feet
• 10 feet
• 15 feet
• 8 feet

NEC Reference: NEC 440.64

Question 14: A portable distribution box at a carnival is installed outdoors. How must it be mounted?

• Weatherproof, bottom 6 in. above grade
• At least 8 ft above grade
• Set directly on the ground
• Inside a locked trailer only

NEC Reference: NEC 525.22(A)

Question 15: Which of these materials has a NEGATIVE temperature coefficient of resistance (its resistance falls as temperature rises)?

• Aluminum
• Copper
• Silver
• Carbon

Question 16: What is the minimum rating of the service equipment for a mobile home?

• 50 A at 120/240 V
• 60 A at 120/240 V
• 100 A at 120/240 V
• 200 A at 120/240 V

NEC Reference: NEC 550.32(C)

Question 17: If the supply frequency of an AC circuit is reduced from 60 Hz to 50 Hz, the inductive reactance (XL) will .............

• Increase
• Decrease
• Remain constant
• Become zero

Question 18: When may two grounded (neutral) conductors terminate under one terminal in a panelboard?

• For any two 15-ampere circuits
• When both neutrals are the same color
• Parallel sets, on a multi-conductor terminal
• Never, under any condition

NEC Reference: NEC 408.41

Question 19: A plug-in circuit breaker is back-fed to supply a panelboard (acting as its main). What does 408.36(D) require?

• A different color from branch breakers
• An extra fastener (more than a pull)
• A rating of 80% of the panel
• A 2-pole breaker only

NEC Reference: NEC 408.36(D)

Question 20: What is the volume of a 4 in. × 2⅛ in. square metal box under Table 314.16(A)?

• 18.0 cu in.
• 21.0 cu in.
• 25.0 cu in.
• 30.3 cu in.

NEC Reference: NEC Table 314.16(A)

Question 21: Fuses are used as overload protection for a 3-phase motor on a 3-wire, 3-phase AC system with one conductor grounded (corner-grounded delta). Where must fuses be installed?

• In every conductor, including the grounded one
• In any two ungrounded conductors
• In one conductor only
• Only in the grounded conductor

NEC Reference: NEC 430.36

Question 22: In a 120/208V 3-phase wye (Y) system, what is the relationship between phase-to-neutral voltage and line-to-line voltage?

• Line-to-line voltage equals phase-to-neutral voltage
• Line-to-line voltage equals √3 (1.732) times phase-to-neutral voltage
• Line-to-line voltage equals 2 times phase-to-neutral voltage
• Line-to-line voltage equals 3 times phase-to-neutral voltage

Question 23: In a 480/277V, 3-phase, 4-wire wye system, what voltage is available for single-pole (120V type) lighting circuits?

• 120 volts
• 277 volts
• 480 volts
• 208 volts

Question 24: Using an inverse time circuit breaker for motor branch circuit short-circuit protection, the maximum breaker size as a percentage of motor FLC per NEC Table 430.52 is .............

• 125%
• 250%
• 300%
• 175%

NEC Reference: NEC 430.52

Question 25: Type NM cable is NOT permitted:

• In attics of dwellings
• In a one-family dwelling
• Concealed in wood-frame walls
• In wet or damp locations

NEC Reference: NEC 334.12(B)

Question 26: Under the 2023 NEC, does the outlet supplying a dwelling unit dishwasher require GFCI protection?

• Only if cord-and-plug connected
• Yes, it requires GFCI protection
• No, dishwashers are exempt
• Only if within 6 ft of the sink

NEC Reference: NEC 210.8(D) and 422.5(A)

Question 27: Under the 2023 NEC, which dwelling locations require GFCI protection for 125-volt through 250-volt receptacles?

• Kitchens, baths, garages, basements, outdoors and more
• Only outdoors and other wet locations
• Only bathrooms and kitchens
• Only where water piping is present

NEC Reference: NEC 210.8(A)

Question 28: A separately derived system (such as a transformer secondary) must have a system bonding jumper connecting the grounded conductor to .............

• The utility neutral only
• The equipment grounding conductor and the derived system enclosure
• The downstream distribution panel neutral
• A ground rod electrode

NEC Reference: NEC 250.30(A)(1)

Question 29: A 24-volt AC control system is supplied by a transformer. When must the 24-volt system be grounded?

• Never; systems under 50 V are never grounded
• Only if it supplies motor loads
• Supply over 150 V to ground, ungrounded, or overhead
• Only if the run is over 30 ft long

NEC Reference: NEC 250.20(A)

Question 30: Surface metal raceways (Wiremold) are NOT permitted to be used in which of the following?

• Dry office spaces
• Hoistways or elevator shafts
• Exposed wall surfaces
• Commercial kitchens

NEC Reference: NEC 386.12