Journeyman Electrician Practice Test 14

Question 1: A separately derived system has one set of 4/0 AWG copper derived ungrounded conductors. A supply-side bonding jumper is run between the transformer and the first disconnect. What is its minimum copper size?

• 4 AWG
• 2 AWG
• 1/0 AWG
• 4/0 AWG

NEC Reference: NEC 250.30(A)(2) and Table 250.102(C)(1)

Question 2: A short section of metal raceway is used only to protect a cable assembly from physical damage. Must it be connected to the equipment grounding conductor?

• Only when it is installed in a wet location
• Only if the section is over 25 ft long
• Yes, every metal raceway always must be
• No, short protective sections are exempt

NEC Reference: NEC 250.86 Exception No. 2

Question 3: At the service, which items must be bonded together?

• Service raceways, cable armor and enclosures
• Only the meter socket and its cover
• Only the main breaker frame and the panel
• Only the grounding electrode and its clamp

NEC Reference: NEC 250.92(A)

Question 4: A bare aluminum equipment grounding conductor is installed. Which rule applies?

• It may be buried directly in the earth
• It must always be at least 2 AWG in size
• It must always be installed in PVC conduit
• No contact with masonry/earth; no end within 18 in.

NEC Reference: NEC 250.120(B)

Question 5: A ground clamp on a water pipe electrode is in a garage where it could be struck by vehicles or tools. What does 250.10 require?

• Enclose it in metal, wood or an equivalent cover
• Nothing; listed clamps need no added protection
• Replace it with a soldered connection instead
• Move the connection outside the building

NEC Reference: NEC 250.10

Question 6: Using the optional dwelling calculation, the general loads total 24 kVA and the central air conditioner is 6 kVA (no electric heat). What is the calculated service load in amperes at 240 V?

• 65 A
• 75 A
• 90 A
• 125 A

NEC Reference: NEC 220.82(B) and (C)

Question 7: Resistors of 10 Ω, 15 Ω and 30 Ω are connected in parallel. What is the total resistance?

• 5 Ω
• 6.7 Ω
• 18.3 Ω
• 55 Ω

Question 8: A single-phase 240-volt motor draws 15 A at a power factor of 0.90. What is its true power?

• 2,400 W
• 3,240 W
• 3,600 W
• 4,000 W

Question 9: In a dwelling kitchen, how may the refrigerator receptacle be supplied?

• Only from the 20 A laundry branch circuit
• Only from a dedicated 240 V branch circuit
• Only from a 15 A general lighting circuit
• A small-appliance circuit, or its own 15 A+ circuit

NEC Reference: NEC 210.52(B)(1)

Question 10: A dwelling attic contains a furnace that needs servicing. What lighting is required?

• A switched light near the furnace, controlled at the entry
• A receptacle for a portable work lamp only
• None; a portable flashlight is acceptable
• Lighting only if the attic floor is decked

NEC Reference: NEC 210.70(A)(3)

Question 11: Two to six service disconnects in separate enclosures are grouped at one location and supplied from one service drop. How many sets of service-entrance conductors are permitted?

• One set may feed each or several enclosures
• Exactly two sets, whatever the number of enclosures
• Only one set for the whole service
• One set for each phase conductor only

NEC Reference: NEC 230.40 Exception No. 2

Question 12: According to 110.7, completed wiring installations must be:

• Painted to match the finish of the building
• Tested by the serving utility before use
• Installed only in metal raceways throughout
• Free of shorts, ground faults and stray grounds

NEC Reference: NEC 110.7

Question 13: Article 100 defines "service lateral" as:

• Underground conductors from the utility to the service point
• The conductors inside the meter socket enclosure
• The feeder conductors to the first subpanel
• The overhead conductors from the pole to the building

NEC Reference: NEC Article 100

Question 14: A transformer delivers 47.5 kW to its load while taking 50 kW from its source. What is its efficiency?

• 105%
• 97.5%
• 95%
• 90%

Question 15: Insulation type XHHW-2 is rated for what maximum operating temperature in dry and wet locations?

• 60 °C
• 75 °C
• 90 °C
• 105 °C

NEC Reference: NEC Table 310.4(1)

Question 16: NM cable runs parallel to a wood stud where nails or screws are likely to penetrate. How far must the cable be from the nearest edge of the framing member (or else protected by a steel plate or sleeve)?

• 2 in.
• 1¼ in.
• 1 in.
• 3/4 in.

NEC Reference: NEC 300.4(D)

Question 17: Twelve current-carrying 12 AWG THHN copper conductors pass through a 20 in. long raceway nipple between two enclosures at 30 °C ambient. What is the ampacity of each conductor in the nipple?

• 15 A
• 20 A
• 25 A
• 30 A

NEC Reference: NEC 310.15(C)(1)

Question 18: Outside feeder tap conductors of unlimited length are permitted when they terminate in a single breaker or set of fuses that limits the load to their ampacity. Where must that overcurrent device be?

• Anywhere inside the building that is convenient
• At least 25 ft from the point of the tap
• At the utility transformer serving the building
• At or right next to the building disconnect

NEC Reference: NEC 240.21(B)(5)

Question 19: When must a circuit breaker be marked with its interrupting rating?

• Always, on every breaker
• Never; it is shown in the catalog
• Only when rated over 100 A
• When it is other than 5,000 A

NEC Reference: NEC 240.83(C)

Question 20: A 1/2 hp motor is manually started, is within sight of its controller, and is on a 120-volt, 20-ampere branch circuit. What provides its overload protection?

• The branch-circuit short-circuit/ground-fault device
• A GFCI receptacle at the motor location
• The motor nameplate rating alone, with no device
• A separate overload relay, which is always required

NEC Reference: NEC 430.32(D)(1)

Question 21: A motor disconnecting means must:

• Close automatically after a power outage
• Open all ungrounded conductors at once
• Open only one of the ungrounded conductors
• Open the grounded conductor before the others

NEC Reference: NEC 430.103

Question 22: May a multiwire branch circuit be used to supply emergency lighting?

• Yes, if the circuit is GFCI protected
• Yes, if identified handle ties are used
• No; they may not be part of a multiwire circuit
• Only within health care facilities

NEC Reference: NEC 700.19

Question 23: Switching devices for pool equipment must be located at least how far horizontally from the inside walls of a pool, unless separated by a barrier or listed for closer use?

• 3 ft
• 5 ft
• 10 ft
• 20 ft

NEC Reference: NEC 680.22(C)

Question 24: In the Class I zone system, what describes a Zone 0 location?

• Combustible dust is present in the air
• Ignitible gas concentrations are present continuously or for long periods
• Ignitible concentrations are likely only during abnormal operation
• Ignitible fibers are stored but not processed

NEC Reference: NEC 505.5(B)(1)

Question 25: On a construction site, may temporary receptacles share a branch circuit with temporary lighting?

• No, not on circuits feeding temporary lighting
• Only for 15-ampere receptacles on the circuit
• Yes, provided the receptacles are GFCI protected
• Yes, in every case on a job site

NEC Reference: NEC 590.4(D)(1)

Question 26: Where must the disconnecting means for fixed electric space-heating equipment be located?

• Inside the heater enclosure only
• Within 100 ft of the heater
• Only at the service panelboard
• Within sight, or lockable open

NEC Reference: NEC 424.19

Question 27: Which recessed luminaires may be installed in direct contact with thermal insulation?

• Only luminaires that use LED lamps
• Non-IC luminaires with 3 in. of clearance
• Type IC (insulation contact) luminaires
• Any recessed luminaire of any type

NEC Reference: NEC 410.116(A)(2)

Question 28: A 3 in. × 2 in. × 2¾ in. device box (14.0 cu in.) will hold one switch and one or more 12 AWG equipment grounding conductors. How many 12 AWG circuit conductors may be added?

• 6
• 4
• 3
• 2

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

Question 29: Auxiliary gutters may not extend more than what distance beyond the equipment they supplement?

• 10 ft
• 20 ft
• 30 ft
• 50 ft

NEC Reference: NEC 366.12

Question 30: What is the rated secondary line current of a 150 kVA, 3-phase transformer with a 480Y/277-volt secondary?

• 104.2 A
• 180.4 A
• 312.5 A
• 541.5 A