Journeyman Electrician Practice Test 24

Question 1: Article 100 defines a grounding electrode as:

• An object giving a direct connection to earth
• The main bonding jumper at the service
• A conductor that bonds equipment to the neutral
• The green screw on a receptacle yoke

NEC Reference: NEC Article 100

Question 2: Which of these may be used as a grounding electrode under 250.52(A)(8), "other local metal underground systems or structures"?

• Metal underground gas piping
• Aluminum conduit buried in the earth
• Swimming pool reinforcing steel
• A metal well casing not bonded to water pipe

NEC Reference: NEC 250.52(A)(8)

Question 3: A receptacle is installed in a floor box. When may the box alone provide the grounding connection to the receptacle?

• When the box is listed for that purpose
• Only in floor boxes in dwelling units
• Never; a bonding jumper is always required
• Whenever the floor box is made of metal

NEC Reference: NEC 250.146(C)

Question 4: An existing detached garage is fed by a 3-wire feeder (two hots and a neutral, no EGC) installed under a previous Code edition. When may the neutral continue to serve as the ground-fault return path at the garage?

• Only if no EGC, no metal paths, no GFPE
• Never; an EGC must be added immediately
• Always, for any existing 3-wire feeder
• Only if a ground rod is driven at the garage

NEC Reference: NEC 250.32(B)(1) Exception No. 1

Question 5: To reduce electrical noise, a listed nonmetallic raceway fitting isolates a computer equipment enclosure from its metal supply raceway. What else is required?

• Removing the EGC from the circuit entirely
• A separate ground rod at the equipment rack
• Nothing; the raceway still grounds the equipment
• An internal insulated EGC per 250.146(D)

NEC Reference: NEC 250.96(B)

Question 6: A parallel circuit has three branches drawing 2 A, 3 A and 5 A. What is the total current from the source?

• 30 A
• 10 A
• 5 A
• 3.3 A

Question 7: A 20,000 sq ft office building has 80 general-purpose receptacle outlets. What receptacle load must be used in the calculation?

• 14,400 VA
• 18,000 VA
• 20,000 VA
• 34,400 VA

NEC Reference: NEC 220.14(K)

Question 8: Using the standard method, a 1,800 sq ft dwelling has two small-appliance circuits, one laundry circuit, a 12 kW range, a 5 kW dryer and a 4.5 kW water heater. What is the calculated service load in amperes at 240 V?

• 95.5 A
• 112.1 A
• 114.2 A
• 130.8 A

NEC Reference: NEC 220.41, 220.52, 220.54, Table 220.45 and Table 220.55

Question 9: Which 125-volt through 250-volt receptacles in a dwelling garage require GFCI protection?

• Only those within 6 ft of the door
• None
• Only the one for the garage door opener
• All of them

NEC Reference: NEC 210.8(A)(2)

Question 10: Equipment used as the service disconnecting means (1,000 V or less) must be:

• Listed and identified as service equipment
• Approved by the serving utility only
• Rated at least 400 A for any occupancy
• Any listed lighting and appliance panelboard

NEC Reference: NEC 230.66

Question 11: A one-family dwelling service has two service disconnects in separate enclosures, rated 60 A and 50 A. The calculated load is 95 A. Does this meet the minimum rating rule?

• No; the largest disconnect must be 100 A
• Yes; any ratings are permitted for two disconnects
• No; each disconnect must be at least 100 A
• Yes; 110 A combined meets the 100 A minimum

NEC Reference: NEC 230.80 and 230.79(C)

Question 12: How are conductor sizes expressed in the NEC?

• In millimeters of diameter only
• In ohms per thousand feet
• In AWG or circular mils
• In amperes of allowable current

NEC Reference: NEC 110.6

Question 13: May a water pipe run above the dedicated electrical space over a panelboard (above the 6 ft zone)?

• Yes, with protection from leaks and drips
• No, never above any panelboard
• Only if it is a fire sprinkler pipe
• Yes, with no conditions at all

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

Question 14: What is the inductive reactance of a 0.1-henry coil in a 60 Hz circuit?

• 377 Ω
• 37.7 Ω
• 26.5 Ω
• 6 Ω

Question 15: What is the allowable ampacity of 8 AWG THHN copper in the 90 °C column of Table 310.16?

• 40 A
• 50 A
• 55 A
• 65 A

NEC Reference: NEC Table 310.16

Question 16: At what temperature rating is the ampacity of Type UF cable determined?

• 90 °C
• 60 °C
• Whatever is marked on the jacket
• 75 °C

NEC Reference: NEC 340.80

Question 17: A branch circuit supplies a 40 A continuous load. Four current-carrying THHN copper conductors share the raceway at 30 °C, and terminals are rated 75 °C. What is the smallest conductor permitted?

• 10 AWG
• 8 AWG
• 6 AWG
• 4 AWG

NEC Reference: NEC 210.19(A)(1), 310.15(C)(1) and 110.14(C)

Question 18: An enclosure for overcurrent devices in a wet location must comply with:

• 110.26
• 312.2
• 408.36
• 430.91

NEC Reference: NEC 240.32

Question 19: Branch-circuit conductors with an ampacity of 27 A supply several general-purpose receptacles for cord-and-plug-connected loads. What is the largest overcurrent device permitted?

• 35 A
• 30 A
• 25 A
• 20 A

NEC Reference: NEC 240.4(B)(1)

Question 20: May one pole of a motor controller be placed in a permanently grounded conductor?

• Only on DC motor controllers
• No, never in any controller
• Yes, if all poles open together
• Yes, always, with no conditions

NEC Reference: NEC 430.85

Question 21: A stationary 2 hp, 230-volt, single-phase motor uses a general-use switch as its disconnecting means. What is the minimum ampere rating of the switch?

• 12 A
• 15 A
• 24 A
• 36 A

NEC Reference: NEC 430.109(C)(1) and Table 430.248

Question 22: 125-volt, 15- and 20-ampere receptacles within what distance of the inside walls of a storable (above-ground) pool require GFCI protection?

• 6 ft
• 10 ft
• 15 ft
• 20 ft

NEC Reference: NEC 680.32

Question 23: A copper ring is used to bond the perimeter surface around an in-ground pool. Where must it be installed?

• 18–24 in. out, 4–6 in. below subgrade
• Within 6 in. of the wall, 12 in. deep
• Anywhere within 10 ft of the pool
• On top of the finished deck surface

NEC Reference: NEC 680.26(B)(2)

Question 24: How must temporary multiwire branch circuits on a construction site be disconnected?

• By unplugging each tool from the cord
• One pole at a time, starting with L1
• They need no disconnecting means at all
• All ungrounded conductors together

NEC Reference: NEC 590.4(E)

Question 25: A hospital service has ground-fault protection of equipment. What is required at the next level of feeder disconnects downstream?

• GFCI protection on every feeder breaker
• AFCI protection on every feeder breaker
• Nothing more is required downstream
• Another step of GFPE on those feeders

NEC Reference: NEC 517.17(B)

Question 26: A 2-prong (non-grounding) receptacle is being replaced in a box where an equipment grounding conductor is present. What must the replacement be?

• A grounding-type receptacle on the EGC
• An isolated-ground receptacle only
• Any receptacle type the owner chooses
• Another non-grounding receptacle

NEC Reference: NEC 406.4(D)(1)

Question 27: When may a wall-mounted oven be cord-and-plug connected?

• Only in commercial kitchens
• Never; ovens must be hard-wired
• Only for servicing or installation
• Whenever the owner prefers a plug

NEC Reference: NEC 422.16(B)(3)

Question 28: A surface-mounted metal panelboard enclosure is installed on an outside wall (wet location). What clearance is required between the enclosure and the wall?

• At least 1 in. of airspace
• At least ¼ in. of airspace
• At least 6 in. of airspace
• None; it may be tight to the wall

NEC Reference: NEC 312.2

Question 29: A 1¼ in. EMT (40% fill = 0.598 sq in.) already contains six 6 AWG THHN (0.0507 sq in. each). How many 10 AWG THHN (0.0211 sq in. each) may be added?

• 11
• 13
• 14
• 28

NEC Reference: NEC Chapter 9, Table 1, Table 4 and Table 5

Question 30: A 75 kVA, 3-phase transformer has a delta-connected 240-volt secondary. The full-load line current is 180.4 A. What current flows in each secondary winding?

• 60.1 A
• 104.2 A
• 180.4 A
• 312.5 A