Colorado Journeyman Electrician Practice Test - Full-Length Test 1

Question 1: Panelboards must be mounted in which of the following?

• Cutout boxes
• Cabinets
• All of these
• Enclosures designed for the purpose

NEC Reference: NEC 408.38

Question 2: A Class III hazardous location is one that has a risk of fire or explosion from:

• Flammable gases or vapors
• Combustible metal dust
• Easily ignitible fibers or flyings (cotton lint, textile dust)
• Explosive chemicals stored in sealed containers

NEC Reference: NEC 500.5(D)

Question 3: Horizontal runs of metal wireway must be supported at intervals not exceeding how many feet?

• 10
• 5
• 15
• 8

NEC Reference: NEC 376.30(A)

Question 4: The conductors shall be protected from abrasion at both entry and exit points of a boxes, conduit bodies and fittings.

• True
• False

NEC Reference: NEC 314.17

Question 5: The branch-circuit overcurrent device of a stationary motor rated ____ or less may serve as the motor's controller.

• 5 hp
• 3 hp
• 1 hp
• 1/8 hp

NEC Reference: NEC 430.81(A)

Question 6: When flexible metal conduit is used for tap connections to luminaires, what is the minimum trade size permitted?

• ⅜ inch
• ½ inch
• ¾ inch
• 1 inch

NEC Reference: NEC 348.20

Question 7: A dwelling unit has a general lighting load of 4,000 VA. What is the feeder demand load for general lighting?

• 3350 VA
• 4000 VA
• 3200 VA
• 3600 VA

NEC Reference: NEC Table 220.45

Question 8: Which circuits must NOT be connected to any system that contains trolley wires with a ground return?

• Circuits for lighting and power
• Grounding conductors
• Ungrounded trolley wires
• Bonding conductors

NEC Reference: NEC 110.19

Question 9: What unit load (VA per sq ft of floor area) is used to determine the minimum number of general lighting branch circuits in a dwelling?

• 2 VA
• 3 VA
• 1 VA
• 4 VA

NEC Reference: NEC 220.41, 210.11(A)

Question 10: A 480V switchboard has exposed live parts on one side of the working space and grounded metal parts on the other (Condition 2). What is the minimum working clearance depth in front of the switchboard?

• 3 feet
• 3½ feet
• 4 feet
• 6 feet

NEC Reference: NEC Table 110.26(A)(1)

Question 11: Service drop conductors passing over a residential driveway must maintain a minimum clearance above the ground of:

• 10 feet
• 12 feet
• 15 feet
• 18 feet

NEC Reference: NEC 230.24(B)(2)

Question 12: Grounding an electrical system is intended mainly to limit high currents.

• True
• False

NEC Reference: NEC 250.4(A)(1)

Question 13: What is the minimum volume allowance required per a No 14 AWG conductor?

• 1.50 in³
• 1.75 in³
• 2.0 in³
• 2.5 in³

NEC Reference: NEC 314.16(B)

Question 14: An ac system of less than 50 volts must be grounded under which condition?

• If the supply transformer primary exceeds 100 V to ground
• If the supply transformer is ungrounded
• If it is used as a feeder
• If it is installed indoors

NEC Reference: NEC 250.20(A)

Question 15: In which location are easily ignitible fibers or flyings stored or handled (other than in manufacturing)?

• Class I Division I
• Class III Division I
• Class III Division 2
• Class I Division 2

NEC Reference: NEC 500.5(D)(2)

Question 16: The equipotential bonding grid for a permanently installed swimming pool, per 680.26(B), uses a solid copper conductor of size:

• Not smaller than 8 AWG solid copper
• 14 AWG stranded copper
• 12 AWG aluminum
• Any size as long as bare

NEC Reference: NEC 680.26(B)

Question 17: A small appliance branch circuit (SABC) in a kitchen can also supply receptacles in which other rooms?

• Bedrooms and hallways
• Pantry, breakfast room, and dining room
• Living room and family room only
• Any room in the house if the circuit has room

NEC Reference: NEC 210.52(B)(1)

Question 18: What is the smallest fixture wire size permitted by the NEC?

• 12 AWG
• 16 AWG
• 18 AWG
• 10 AWG

NEC Reference: NEC 402.6

Question 19: An enclosure for switches or overcurrent devices can never be used as a raceway for conductors feeding through.

• True
• False

NEC Reference: NEC 312.8

Question 20: What is the minimum load that must be used for each 2-wire laundry branch circuit in a dwelling unit?

• 1500 Volt-Amperes
• 1200 Volt-Amperes
• 1000 Volt-Amperes
• 800 Volt-Amperes

NEC Reference: NEC 220.52(B)

Question 21: What is the minimum ampere rating of the short-circuit and ground-fault protective device permitted for an individual motor-compressor?

• 10 A
• 15 A
• 20 A
• 25 A

NEC Reference: NEC 440.22(A)

Question 22: Up to how many sets of 5-wire feeders may use a common neutral?

• 2
• 3
• 4
• 5

NEC Reference: NEC 215.4

Question 23: The bottom of the mobile home service disconnecting means enclosure must be not less than how many feet above finished grade or the working platform?

• 1
• 2
• 1/2
• 3

NEC Reference: NEC 550.32(F)

Question 24: An industrial machine nameplate says: 240V, 3-phase, supply current = 60A. What is the minimum conductor ampacity for the supply circuit to this machine?

• 60 A (match the nameplate)
• 69 A (115% of supply current)
• 75 A (125% of supply current)
• 80 A (next standard size)

NEC Reference: NEC 670.4(B)

Question 25: The 25-foot feeder tap rule (240.21(B)(2)) allows a tap up to 25 feet without an OCPD at the tap point. What minimum ampacity must the tap conductors have compared to the feeder overcurrent device?

• At least 1/10 of the feeder OCPD rating
• At least 1/3 of the feeder OCPD rating
• Equal to the feeder conductor ampacity
• At least 1/2 of the feeder OCPD rating

NEC Reference: NEC 240.21(B)(2)

Question 26: The general lighting demand factors may NOT be used to determine the number of branch circuits required for general illumination.

• True
• False

NEC Reference: NEC 220.45

Question 27: Service drop conductors passing over a public street or road subject to truck traffic must maintain a minimum ground clearance of:

• 12 feet
• 15 feet
• 18 feet
• 22 feet

NEC Reference: NEC 230.24(B)(4)

Question 28: The NEC has an informational note that recommends keeping voltage drop at or below what percentage for branch circuits, and what combined percentage for the whole system (feeder + branch)?

• 2% branch circuit, 3% combined
• 3% branch circuit, 5% combined
• 5% branch circuit, 8% combined
• 5% anywhere in the system

NEC Reference: NEC 210.19(A)(1) IN, 215.2(A)(1) IN

Question 29: The dedicated electrical space above a panelboard must extend how far above the top of the equipment?

• 3 ft above the top of the equipment
• 6 ft above the top of the equipment (or to structural ceiling)
• To the highest point of the room only
• No dedicated space is required above the panel

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

Question 30: A commercial kitchen has two pieces of electric cooking equipment. What demand factor applies per Table 220.56?

• 100 %
• 80 %
• 70 %
• 90 %

NEC Reference: NEC Table 220.56

Question 31: An industrial heating appliance on a 45 A branch circuit is supplied by a tap conductor. What is the minimum tap conductor ampacity?

• 10 amperes
• 15 amperes
• 20 amperes
• 30 amperes

NEC Reference: NEC 210.19(A)(4)

Question 32: A 4-inch square metal box, 1¼ inches deep, has a minimum volume of:

• 21 cubic inches
• 18 cubic inches
• 16 cubic inches
• 30 cubic inches

NEC Reference: NEC 314.16(A)

Question 33: What is the maximum continuous load that can be connected to 240 volts 20 ampere branch circuit?

• 16 amperes
• 20 amperes
• 14 amperes
• 10 amperes

NEC Reference: NEC 210.20

Question 34: A 120 volts branch circuit supplies only cord and plug type window conditioner has an ampere rating of 20 amperes. What is the maximum full load current rating of an air conditioner?

• 16 amperes
• 10 amperes
• 20 amperes
• 15 amperes

NEC Reference: NEC 440.62

Question 35: Shore power receptacles at a marina must have ground-fault protection set to open at not more than:

• 30 mA
• 100 mA
• 300 mA
• 1 A

NEC Reference: NEC 555.35

Question 36: Electrical equipment installed in a chemical storage room where the atmosphere could corrode metal parts must be:

• Standard equipment — corrosion is a maintenance issue, not a code issue
• Equipment approved or listed for use in the specific corrosive environment
• Equipment rated NEMA 1 with a painted finish
• No restriction — any equipment in a metal enclosure is acceptable

NEC Reference: NEC 110.11

Question 37: Live parts of motors and controllers operating at ____ volts or more between terminals must be guarded.

• 75
• 50
• 120
• 240

NEC Reference: NEC 430.232

Question 38: What type of lampholders are required on branch circuits rated over 20 amperes?

• Brass
• Porcelain
• Heavy-duty
• Keyless

NEC Reference: NEC 210.21

Question 39: A supplementary overcurrent protective device (like the small fuse inside a light fixture) can be used in addition to branch circuit protection. What can it NOT do?

• Protect an individual component inside a luminaire
• Serve as the branch circuit overcurrent protection for the conductors
• Be used in listed electrical equipment
• Blow before the branch circuit breaker does

NEC Reference: NEC 240.10

Question 40: Cord-and-plug-connected utilization equipment must not exceed what percentage of the branch-circuit rating?

• 80
• 70
• 90
• 95

NEC Reference: NEC 210.23(A)(1)

Question 41: Constant-wattage heating cables embedded in concrete floors must not exceed how many watts per linear meter?

• 54 W/m (16½ W/ft)
• 16½ W/m
• 36 W/m
• 22½ W/m

NEC Reference: NEC 424.44(A)

Question 42: Branch circuit conductors feeding equipment with 60°C rated terminations must be sized using which column from Table 310.16, regardless of the conductor insulation temperature rating?

• The 90°C column — THHN wire is 90°C rated
• The 75°C column — THWN is more commonly used
• The 60°C column — the terminal rating limits you to 60°C ampacity
• Either the 60°C or 75°C column, whichever gives a smaller wire

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

Question 43: A separately derived system (such as a transformer) can have the system bonding jumper placed at the transformer or at the first disconnect. If both locations are used, what problem does this create?

• No problem — bonding at two locations improves fault current capacity
• Neutral current and fault current will flow on the metal conduit, creating a stray current hazard
• The second bond causes the OCPD to trip unnecessarily
• Both locations are required by 250.30 to ensure reliability

NEC Reference: NEC 250.30(A)(1)

Question 44: What is the smallest aluminum conductor permitted for underground service conductors?

• 6 AWG
• 8 AWG
• 10 AWG
• 12 AWG

NEC Reference: NEC 230.31(B)

Question 45: A conductor in a flexible cord has an ampacity of 150 amperes. What is the allowable ampacity of each conductor if 5 current-carrying conductors are in the cord?

• 120 amperes
• 135 amperes
• 140 ampere
• 105 amperes

NEC Reference: NEC 400.5(A)(3)

Question 46: When four or more fixed appliances (other than ranges, dryers, A/C, or space heating) are on a feeder, the demand factor per 220.53 allows you to use what percentage of the total connected load?

• 50%
• 65%
• 75%
• 100%

NEC Reference: NEC 220.53

Question 47: A 400A 277/480V 3-phase 4-wire feeder uses copper conductors at 75°C. From Table 310.16, the smallest size that meets 400A is:

• 400 kcmil
• 500 kcmil
• 600 kcmil
• 700 kcmil

NEC Reference: NEC Table 310.16

Question 48: In a 14 feet residential hallway, how many minimum number of receptacles are required?

• 2
• 1
• 3
• 4

NEC Reference: NEC 210.52

Question 49: How many service disconnects are allowed per service, per 230.71?

• Two
• Four
• Six
• No limit — as many as needed

NEC Reference: NEC 230.71(B)

Question 50: An 8-unit multifamily building has a 5 kW electric dryer in each unit. What is the total dryer demand load for the service or feeder?

• 24 KW
• 40 KW
• 20 KW
• 30 KW

NEC Reference: NEC 220.54

Question 51: A panelboard is equipped with 30-ampere snap switches. Its overcurrent protection must be rated not more than:

• 200 amperes
• 100 amperes
• 50 amperes
• 150 amperes

NEC Reference: NEC 408.36(A)

Question 52: What is the minimum allowable rating of 3-wire service-entrance conductors for a single-family dwelling unit?

• 100 amperes
• 125 amperes
• 150 amperes
• 75 amperes

NEC Reference: NEC 230.42(B)

Question 53: When must a grounding electrode conductor be protected from physical damage along its entire length?

• A GEC never needs physical protection — it is buried or in conduit always
• Copper GECs smaller than 6 AWG that are exposed must be protected by a raceway or armor
• Any GEC run along a wall must be in rigid metal conduit
• GEC protection is only required within 8 feet above the floor

NEC Reference: NEC 250.64(B)

Question 54: A 30 kVA arc welder rated for nonautomatic duty cycle 60% has a primary current of 50A. Per 630.11(A), branch-circuit conductor ampacity is calculated using the multiplier:

• 0.55
• 0.78
• 1.00
• 1.25

NEC Reference: NEC Table 630.11(A)

Question 55: Flexible metal conduit (FMC) used as a whip connection to a light fixture has a maximum allowed length of:

• 3 feet
• 4½ feet
• 6 feet
• 10 feet

NEC Reference: NEC 348.20(B)(1)

Question 56: A multiwire branch circuit (two hot legs sharing a neutral) on a 120/240V single-phase panel must have what protective device at the panel?

• Two individual single-pole breakers in any slot position
• A 2-pole breaker or two single-pole breakers with an approved handle tie
• A GFCI breaker that covers both legs
• No special device is needed if the neutral is properly sized

NEC Reference: NEC 210.4(B)

Question 57: During construction, temporary feeder cables that run on the ground across a work site must be:

• Left loose on the ground — construction sites are temporary
• Protected from physical damage when subject to physical damage
• Buried at least 6 inches deep even for temporary runs
• Installed in conduit just like permanent wiring

NEC Reference: NEC 590.4(B)

Question 58: What is the minimum volume of a 4-inch round or octagonal metal box, 1½ inches deep?

• 12.5 cu in
• 15.5 cu in
• 21.5 cu in
• 18.5 cu in

NEC Reference: NEC Table 314.16(A)

Question 59: What general lighting unit load is used for an office building, per NEC Table 220.42(A)?

• 1.3 VA per sq ft
• 3 VA per sq ft
• 3.5 VA per sq ft
• 5 VA per sq ft

NEC Reference: NEC Table 220.42(A)

Question 60: The branch-circuit short-circuit and ground-fault protective device for a single motor-compressor must in no case exceed what percent of its rated-load current?

• 175
• 225
• 200
• 150

NEC Reference: NEC 440.22(A)

Question 61: A single-phase room air conditioner rated not more than ____ at 250 volts may be considered a single motor unit for branch-circuit purposes.

• 30 amperes
• 40 amperes
• 50 amperes
• 60 amperes

NEC Reference: NEC 440.62(A)

Question 62: In a 120/240V, 4-wire delta service (high-leg delta), one phase has a higher voltage to ground than the other two. This phase must be identified with what color, and which phase position is it in?

• Red color, A phase position
• Orange color, B phase (middle) position
• Yellow color, C phase position
• Brown color — no specific phase position required

NEC Reference: NEC 230.56

Question 63: A 6 AWG THW copper conductor is installed in a room where the ambient temperature is 52°C. What is its allowable ampacity?

• 65 amperes
• 50 amperes
• 67 amperes
• 44 amperes

NEC Reference: NEC Table 310.15(B)(1)

Question 64: A panelboard contains snap switches rated 25 amperes. The panelboard must have overcurrent protection rated not more than:

• 200 amperes
• 30 amperes
• 120 amperes
• 150 amperes

NEC Reference: NEC 408.36(A)

Question 65: Per 240.4(B), when the conductor ampacity does not match a standard OCPD size, you may use the next larger standard size. When is this NOT allowed?

• When the next size up would be more than 10% larger than the conductor ampacity
• For 14, 12, and 10 AWG conductors — these have hard maximum OCPD sizes
• For any conductor rated less than 100A
• The next-size-up rule is always permitted for residential wiring

NEC Reference: NEC 240.4(B)

Question 66: A panelboard is rated 100 amperes. Per NEC 408.36, the overcurrent device protecting it must be rated:

• 125 amperes
• Not more than 100 amperes
• At least 125% of the panelboard rating
• Any size listed for the panelboard bus

NEC Reference: NEC 408.36

Question 67: What is the maximum primary overcurrent device rating for a single-phase 480 V to 120 V transformer rated 1.8 kVA, protected on the primary only?

• 6 A
• 7 A
• 4 A
• 10 A

NEC Reference: NEC 450.3

Question 68: Vertical runs of metal wireway must be securely supported at intervals not exceeding how many feet, with not more than one joint between supports?

• 15
• 10
• 5
• 8

NEC Reference: NEC 376.30

Question 69: Article 411 low-voltage lighting systems operate at not more than how many volts ac?

• 30 volts
• 25 volts
• 40 volts
• 35 volts

NEC Reference: NEC 411.1

Question 70: What is the minimum vertical clearance of overhead service conductors above a roof?

• 6 feet
• 8½ feet
• 10 feet
• 12 feet

NEC Reference: NEC 230.24(A)

Question 71: What is the maximum number of receptacles permitted on a 15-ampere, 120-volt branch circuit in a retail shop?

• 10
• 8
• 9
• 12

NEC Reference: NEC 220.14(I)

Question 72: What is the minimum height of the service drop at the electrical service entrance to a building (150 volts or less to ground)?

• 10 feet
• 8 feet
• 12 feet
• 15 feet

NEC Reference: NEC 230.24(B)(1)

Question 73: What is the minimum trade size of liquidtight flexible metal conduit (LFMC) permitted for general use?

• ½ inch
• ⅜ inch
• ¾ inch
• 1 inch

NEC Reference: NEC 350.20(A)

Question 74: A motor nameplate shows FLA = 40A and temperature rise = 50°C. There is no service factor listed. What is the maximum overload relay setting allowed?

• 40 A (FLA with no multiplier)
• 46 A (115% of FLA)
• 50 A (125% of FLA)
• 56 A (140% of FLA)

NEC Reference: NEC 430.32(A)(1)

Question 75: The diagram shows a 400A feeder from a main switchboard to a distribution panel. A 100A tap is taken from the feeder 20 feet from the distribution panel without an overcurrent device at the tap point. The 100A tap conductor is 3 AWG copper (rated 110A). Is this tap compliant with the 25-foot rule?

• Yes — the 3 AWG conductor fits within the 25-foot rule
• No — the tap conductor must be at least 1/3 of 400A (133A), and 3 AWG is only 110A
• Yes — the 100A panel will protect the tap conductors
• No — the tap is 20 feet, and any tap over 15 feet requires its own OCPD

NEC Reference: NEC 240.21(B)(2)

Question 76: A 480V switchboard at an industrial plant has a calculated available fault current of 42,000 amps at the bus. What is the minimum interrupting rating required for the OCPDs in this switchboard?

• 10,000A AIC — standard panel rating
• 22,000A AIC — the next common rating above residential
• 42,000A AIC or higher
• No AIC rating is required on the load side of the service

NEC Reference: NEC 110.9

Question 77: In a Class I, Division 1 hazardous location, motor enclosures must be rated as:

• Weatherproof (NEMA 3R)
• Drip-proof (open frame is fine)
• Explosion-proof (listed for the gas or vapor group)
• GFCI protected — no special enclosure needed

NEC Reference: NEC 501.125(A)

Question 78: What is the maximum total of bends permitted in an EMT run between pull points?

• 60 degrees
• 90 degrees
• 180 degrees
• 360 degrees

NEC Reference: NEC 358.26

Question 79: A 20 A, 120 V branch circuit supplies only one cord-and-plug window air conditioner. Which full-load rating is NOT permitted for the unit?

• 10 amp
• 16 amp
• 18 amp
• 20 amp

NEC Reference: NEC 440.62(B)

Question 80: What is the maximum allowable conductor fill for 4in * 4 in wireway?

• 16 sq in
• 8 sq in
• 3.2 sq in
• 4.8 sq in

NEC Reference: NEC 376.22(A)

Question 81: Underground conductors carried up a pole must be protected from physical damage up to at least what height?

• 8 feet
• 12 feet
• 16 feet
• 6 feet

NEC Reference: NEC 300.5(D)(1)

Question 82: A Colorado commercial building has interior metal gas piping. Per 250.104(B), what does the NEC require if this piping may become energized?

• It must be bonded per 250.104(B)
• Gas piping is always exempt from bonding
• Only plastic gas piping requires bonding
• Bonding gas piping is solely the utility's job

NEC Reference: NEC 250.104(B)

Question 83: An instantaneous-trip circuit breaker is used ahead of a motor starter with its own overload relay, as part of a listed combination motor controller. What is the maximum base percentage Table 430.52 allows for this breaker?

• 300 percent
• 500 percent
• 800 percent
• 1,000 percent

NEC Reference: NEC Table 430.52

Question 84: A commercial building has a feeder tap 20 feet long inside a large single-story warehouse. Per 240.21(B)(2), what is one condition of the 25-foot tap rule?

• The tap conductor ampacity must be at least one-third the ampacity of the feeder overcurrent device
• The tap can be any size regardless of the feeder rating
• Taps over 10 feet are never permitted under any rule
• The tap must always match the feeder conductor size exactly

NEC Reference: NEC 240.21(B)(2)

Question 85: A 240V single-phase feeder in a Michigan commercial building carries a calculated load of 30,000 VA. What is the calculated line current?

• 100 amps
• 125 amps
• 150 amps
• 175 amps

Question 86: A squirrel-cage motor branch circuit is protected with a standard, non-time-delay fuse. What base percentage of full-load current does Table 430.52 allow?

• 175 percent
• 250 percent
• 300 percent
• 400 percent

NEC Reference: NEC Table 430.52

Question 87: A homeowner installs a 50-amp, 240-volt EV charger (120 volts to ground). Does 625.43 require a separate, readily accessible disconnecting means for it?

• No, the 625.43 disconnect rule applies only to equipment rated over 60 A or over 150 V to ground
• Yes, every EV charger needs a separate 200-amp disconnect
• Yes, but only if it is installed outdoors
• Yes, a GFCI breaker must be added as the disconnect

NEC Reference: NEC 625.43

Question 88: Rigid nonmetallic conduit (PVC) is direct-buried under a yard, not under a building or driveway. What minimum cover does Table 300.5 require?

• 12 inches
• 18 inches
• 24 inches
• 30 inches

NEC Reference: NEC Table 300.5

Question 89: A Colorado dwelling has a family room. Per 210.12(B), does this room require AFCI protection?

• Yes, family rooms are included in the list of areas requiring AFCI protection
• No, family rooms are always exempt from AFCI
• AFCI protection has never applied to family rooms
• AFCI is only required if the room exceeds 400 square feet

NEC Reference: NEC 210.12(B)

Question 90: Per NEC 450.9, dry-type transformers shall be installed so that the ____ required for cooling purposes is not blocked or obstructed.

• High-voltage primary winding
• Ventilation required for cooling
• Conduit knockout opening
• Grounding terminal

NEC Reference: NEC 450.9