Journeyman Electrician Practice Test 18

Question 1: A building has a metal underground water pipe, a concrete-encased electrode and a ground ring. What does 250.50 require?

• Use whichever electrode has the lowest resistance
• Use only the water pipe and ignore the others
• Use only the concrete-encased electrode
• Bond all of them together into one system

NEC Reference: NEC 250.50

Question 2: What is the minimum trade size of a galvanized steel pipe used as a pipe electrode?

• 1¼
• 1
• ¾
• ½

NEC Reference: NEC 250.52(A)(5)

Question 3: A ground ring encircling a building must consist of at least 20 ft of bare copper conductor not smaller than:

• 6 AWG
• 4 AWG
• 2 AWG
• 1/0 AWG

NEC Reference: NEC 250.52(A)(4)

Question 4: A metal water pipe used as a grounding electrode has a water meter and a filter that may be removed for service. What is required?

• Bonding jumpers around them, long enough for removal
• Nothing; the metal water pipe itself is enough
• A second ground rod driven on each side of the meter
• Dielectric unions installed on both sides of the meter

NEC Reference: NEC 250.68(B)

Question 5: A service has 600 kcmil aluminum ungrounded conductors in a single raceway. What is the minimum size aluminum supply-side bonding jumper?

• 4/0 AWG
• 3/0 AWG
• 2/0 AWG
• 1/0 AWG

NEC Reference: NEC 250.102(C)(1) and Table 250.102(C)(1)

Question 6: A 12-unit apartment building qualifies for the optional multifamily calculation. Each unit has a connected load of 24,000 VA. What is the feeder demand load?

• 288,000 VA
• 129,600 VA
• 123,840 VA
• 118,080 VA

NEC Reference: NEC 220.84 and Table 220.84

Question 7: A 4,800-watt heater is rated at 240 V. What power does it produce if connected to 208 V?

• 3,605 W
• 4,160 W
• 4,800 W
• 5,538 W

Question 8: Three identical resistors are connected in series across 120 V. What is the voltage across each resistor?

• 13.3 V
• 40 V
• 120 V
• 360 V

Question 9: In a dwelling unit, which receptacles in a laundry area require GFCI protection?

• All 125-V through 250-V receptacles there
• Only receptacles within 6 ft of a laundry sink
• None; laundry areas are not GFCI locations
• Only the receptacle serving the clothes washer

NEC Reference: NEC 210.8(A)(10)

Question 10: A dwelling has an outdoor air-conditioning condenser on a 240-volt, 30-ampere branch circuit. Does it require GFCI protection?

• Only if it is within 6 ft of a swimming pool
• Only if the branch circuit uses NM cable
• No; only receptacles need GFCI protection
• Yes; outdoor outlets of 50 A or less need it

NEC Reference: NEC 210.8(F)

Question 11: A branch circuit supplies 30 A of continuous load and 8 A of noncontinuous load. What is the minimum standard overcurrent device rating?

• 40 A
• 45 A
• 50 A
• 60 A

NEC Reference: NEC 210.20(A)

Question 12: What is the minimum width of the working space in front of a panelboard?

• 36 in. in all cases regardless of equipment width
• 24 in., or the width of the equipment if greater
• The width of the equipment only, with no minimum
• 30 in., or the equipment width if greater

NEC Reference: NEC 110.26(A)(2)

Question 13: Indoors, the dedicated electrical space above a switchboard or panelboard extends from the floor to what height?

• 3 ft above the top of the equipment
• 6 ft above the equipment or to the structural ceiling
• 6½ ft above the finished floor in all cases
• 10 ft above the floor or to the suspended ceiling

NEC Reference: NEC 110.26(E)(1)(a)

Question 14: A disconnect that requires servicing is located above a lay-in suspended ceiling. What is the minimum size of the ceiling opening used to reach it?

• 12 in. × 12 in.
• 18 in. × 18 in.
• 22 in. × 22 in.
• 30 in. × 30 in.

NEC Reference: NEC 110.26(A)(4)

Question 15: How may a 4 AWG or larger grounded conductor with black insulation be identified?

• White or gray marking at its terminations
• It can never be re-identified as a grounded conductor
• Green tape applied at each end of the conductor
• A tag marked "neutral" at the panel end only

NEC Reference: NEC 200.6(B)

Question 16: Insulated conductors exposed to the direct rays of the sun must be:

• Listed sunlight resistant, or covered with listed tape or sleeving
• Painted white to reflect the heat of the sun
• Rated for at least 105 °C in wet and dry locations
• Installed only in rigid or intermediate metal conduit

NEC Reference: NEC 310.10(D)

Question 17: A 16 in. nipple of 1 in. EMT (total area 0.864 sq in.) joins two enclosures. What is the maximum conductor fill permitted in the nipple?

• 0.35 sq in.
• 0.46 sq in.
• 0.52 sq in.
• 0.86 sq in.

NEC Reference: NEC Chapter 9, Table 1, Note 4 and Table 4

Question 18: In a high-bay manufacturing building with walls over 35 ft high, a feeder tap is made under 240.21(B)(4). What is the maximum total tap length?

• 25 ft
• 35 ft
• 50 ft
• 100 ft

NEC Reference: NEC 240.21(B)(4)

Question 19: When may Edison-base fuses be installed?

• In any new 120-volt branch circuit up to 30 A
• Only on 240-volt circuits in dwelling units
• Only in new commercial and industrial buildings
• Only as replacements where no overfusing or tampering

NEC Reference: NEC 240.51

Question 20: When sizing branch-circuit conductors for a general-purpose AC motor, which current value is used?

• The locked-rotor current of the motor at start
• The nameplate current multiplied by the service factor
• The current marked on the motor nameplate
• The full-load current from the NEC motor tables

NEC Reference: NEC 430.6(A)(1)

Question 21: A 25 hp, 460-volt, 3-phase squirrel-cage motor is protected by an inverse time breaker. What is the maximum breaker rating using the next-size-up exception?

• 100 A
• 90 A
• 85 A
• 80 A

NEC Reference: NEC 430.52(C)(1) Exception No. 1 and Table 430.250

Question 22: May underground wiring be run under a permanently installed swimming pool?

• No, unless it is needed to supply pool equipment
• Yes, if it is installed in rigid metal conduit
• Yes, with any listed wiring method for direct burial
• Yes, if it is buried at least 24 in. below the pool

NEC Reference: NEC 680.11

Question 23: An optional standby generator for a home uses an automatic transfer switch with no load management. How large must the generator be?

• Large enough only for the loads the owner selects
• Any size, because optional standby is the owner's choice
• At least 50% of the dwelling service rating
• Able to supply the full load the switch transfers

NEC Reference: NEC 702.4(B)(2)

Question 24: At a carnival, which receptacles require GFCI protection?

• 125-V, 15- and 20-A non-locking ones the public can reach
• Only receptacles mounted on the amusement rides
• None, because carnival equipment is portable
• Only the 240-volt receptacles on the midway

NEC Reference: NEC 525.23(A)

Question 25: In a hospital, where is an isolated ground receptacle NOT permitted?

• In a mechanical or equipment room
• Within a patient care vicinity
• In any hospital corridor or hallway
• At a nurses' station desk or counter

NEC Reference: NEC 517.16(A)

Question 26: A 15-ampere, 125-volt receptacle is installed outdoors in a wet location. What kind of enclosure (cover) is required?

• No cover is needed if the receptacle is a GFCI type
• Any metal cover rated for the box it is mounted on
• Weatherproof whether or not a plug is inserted
• A flat cover that is weatherproof only when closed

NEC Reference: NEC 406.9(B)(1)

Question 27: Luminaires must be installed so that adjacent combustible material is not subjected to temperatures above:

• 60 °C (140 °F)
• 75 °C (167 °F)
• 90 °C (194 °F)
• 105 °C (221 °F)

NEC Reference: NEC 410.11

Question 28: A ceiling outlet box intended for a luminaire must be designed to support a luminaire weighing at least:

• 70 lb
• 50 lb
• 35 lb
• 25 lb

NEC Reference: NEC 314.27(A)(2)

Question 29: Liquidtight flexible metal conduit (LFMC) must be secured within 12 in. of each box and at intervals not exceeding:

• 3 ft
• 4½ ft
• 6 ft
• 10 ft

NEC Reference: NEC 350.30(A)

Question 30: An indoor dry-type transformer rated 75 kVA (not over 112.5 kVA) must be separated from combustible material by at least what distance, unless a fire-resistant barrier is used?

• 24 in.
• 18 in.
• 12 in.
• 6 in.

NEC Reference: NEC 450.21(A)