IEC Y2S1 part 3
A fixture stud in a box is considered the equivalent of how many conductors?
B. 1
The smallest trade size EMT available that can be installed between two big pull boxes is ___.
B. 1/2
Trade size 1/2 IMC and RMC use the same fittings. Which of them has the greater wall thickness?
B. 1/2 RMC
Refer to partial circuit plan shown in Figure 115.103. You are required to size the box that will contain a split-wired receptacle. If the cables entering this box were all #12 MC cables, what is the smallest 4" square metal box that could be used here? The box will have a 1"-rise plaster ring installed that adds a volume of 6.1 in3 to the total volume. The MC cables will be connected to the box using external connectors. There are NO cable clamps within this box. Hint: don't forget to count the wires for the device and the ground(s) that are in the MC cable.
B. 11/2
PVC shall not be permitted where subject to ambient temperature in excess of ________ degrees Farenheit unless listed otherwise.
B. 122
What is the ampacity of a 1/0 TW copper conductor?
B. 125 amps
Armored cable installed in thermal insulation shall have conductors rated at ___. The ampacity of cable installed in these applications shall be that of 60 degree C conductors.
B. 194 degrees F
How many 12/2 AWG with ground, type NM cables are permitted to be installed in an outlet box that is 18 cubic inches and has a duplex receptacle installed in the box?
B. 2
What is the minimum trade size RMC permitted to be installed between two panelboards that are 5 feet apart? The RMC will contain four 4/0 AWG conductors and one 4 AWG ground. All conductors are THHN/THWN.
B. 21/2
The circular mil area of a 250 kcmil bare copper cable is ___ cmils
B. 250,000
Where conduit is threaded in the field, a standard conduit cutting die with a ___ inch taper per foot shall be used.
B. 3/4
Which of the following is the maximum number of current-carrying conductors that can be used at any cross section of a wireway without requiring the use of ampacity adjustment factors?
B. 30
When installed in raceways, conductors ____ AWG and larger shall be stranded.
A. 8
For working or walking surfaces, the open sides of the upper levels shall be ___ to protect employees from falling to the lower levels.
A. guarded
Where a conduit passes through an exterior wall and enters a panel mounted on the interior, seals or plugs ___ required.
B. are
Among the conductors listed below, all except ___ are permitted to be connected in parallel.
C. 1 AWG
What is the cubic-inch allowance for a 10 AWG conductor?
C. 2.50
Do not use a ladder that is ___.
D. any of these
A 500,000-circular mil cable is composed of how many strands?
A. 37
Where installed in raceways, conductors of size ___ AWG and larger shall be stranded.
A. 8
The circular mil area of a 10 AWG bare copper conductor is ___ cmils
B. 10380
When eight (8) current-carrying conductors are in one conduit, the ampacity of each conductor is adjusted to ____ percent.
B. 70
According to the NEC® an 8 AWG bare solid copper conductor has a cross-sectional area of ___ square inches.
D. .013
If a 500,000-circular mil (500 kcmil) cable is composed of 37 strands, what is the diameter of each strand of the cable per Table 8 in the NEC®?
D. .116 inches
The DC resistance @ 167 degrees F for a 2/0 AWG bare aluminum conductor would be ___ ohm per thousand feet of conductor.
D. 0.159
Which of the following conductors can be used in a damp location?
D. XHH
Which of the following conductor arrangements is permitted by the NEC®?
D. a or b only
According to ___ in the NEC®, unused knockouts and other openings in electrical boxes and cabinets are required to be closed.
D. all of these
Many ___ are the result of poor housekeeping practices.
D. all of these
The overall diameter of a 1/0 bare stranded copper conductor is ___ inches.
A. .372
A cabinet or cutout box is constructed of sheet steel, the metal thickness shall not be less than ___ inch uncoated.
A. 0.053
When installing #1 RHH conductors in a conduit, each conductor has a value of ____ when calculating conduit fill.
A. 0.2660 square inches
The minimum trade size EMT required is ___. This is a run that is 45' long. The following conductors will be installed: four-#12 THHN/THWN + three-#10 THHN/THWN + two-#6 THHN/THWN.
A. 1
Except by special permission, no conductor larger than ___ shall be installed in cellular metal floor raceways.
A. 1/0 AWG
Enclosures for overcurrent devices in damp or wet locations shall be identified for use in such locations and shall be mounted so there is at least ___ inch airspace between the enclosure and the wall.
A. 1/4
Refer to Figure 210.6, shown above. The conductors connected to the terminal lugs are 350 kcmil. The minimum wire bending space required at II is ___ inches. These lugs are NOT removable.
A. 12
MC cable is used to connect a 2 x 4 lay-in fluorescent luminaire to a "home run" box as shown in Figure 208.2. The length of the cable between the box and the luminaire is 26 feet. The maximum distance between the box and support #1 is ___.
A. 12 inches
The minimum size conductor permitted in commercial buildings for branch circuits up to and including 2000 volts is ___ AWG.
A. 14
What is the circular mil area of a 3/0 AWG conductor?
A. 167,800
Refer to Figure 208.51. The minimum CALCULATED dimension for "height" is ___ inches. All conductors enter the right size of the pull box and exit the bottom.Conduit G = 2" Conduit H = 21/2" Conduit J = 11/2"Conduit K = 1" Conduit L = 11/2" Conduit M = 2" Conduit N = 2"
A. 181/2
The smallest standard size metal box that can be used for the following is a ___. one- 1/2" romex (exterior) connectorone- 14-2 w/ ground NM cableone- 20 amp 240 volt duplex receptacleone- PVC (exterior) connectortwo- 12 AWG conductors to be connected to the receptacleone- 12 AWG equipment grounding conductortwo- 14 AWG conductors to be connected to the NM cable with wire nuts
A. 3-1/2" deep masonry box
When installing more than two conductors in a 50 foot run of 3 inch intermediate metal conduit, the maximum area that can be filled with conductors is ______ square inches.
A. 3.169
The minimum thickness for a cast aluminum box measuring 6" X 4" X 31/2" is ___ inches.
A. 3/32
In a 30-foot run of conduit containing two conductors the maximum cross-sectional area that can be occupied by conductors is ___ %.
A. 31
Section ___ of the NEC® permits nonmetallic outlet and device boxes to be installed with nonmetallic sheathed cable.
A. 314.3
The minimum CALCULATED dimension for "width" shown in Figure 208.54 is ___ inches. All conductors enter the left side of the pull box and exit the bottom.
A. 34
A section of 8" x 8" wireway is shown in Figure 208.61. The maximum number of 2/0 AWG THHN/THWN conductors that can be installed in the wireway is ___.
A. 57
The ampacity of UF cable shall be that of ___ degree C conductors.
A. 60
The ampacity of types NM and NMC cable shall be that of ___ degree C conductors.
A. 60
What is the MINIMUM bend radius for 1 in. diameter corrugated sheath MC cable?
A. 7 in.
The conductors, including splices and taps in metal surface raceway shall not fill the raceway to more than ___ percent of its area at that point.
A. 75
The minimum wire bending space required at the top and bottom of a panelboard that has three 3/0 AWG conductors connected to each busbar is ___.
A. 8 in.
Refer to Figure 208.12, shown above. You will need at least ___ straps to support the conduit between enclosures A & B. Trade size 2 IMC with threaded couplings and connectors is used. You will cut and thread the conduit as required. The distance from enclosure A to B is 123 feet.
A. 9
Does the NEC® permit the installation shown above at X in Figure 208.1? The box is supported only by the conduits. The distance from the top of the head track to the bottom of the 4-SQ box is 2 inches. Both conduits are EMT and are attached to the box with steel compression connectors (not visible in drawing).
A. No
Section 314.3 of the NEC® permits nonmetallic outlet and device boxes to be installed with which of the following?
A. Nonmetallic sheathed cable
___ boxes shall not be used where conduits or connectors requiring the use of locknuts or bushings are to be connected to the side of the box.
A. Round
All power must be turned off before working on or inside a transformer.
A. True
When making up the branch circuit wires to the breakers in a newly installed panelboard, you found that some of the wires were cut too short. Does the NEC® permit any of these to be spliced with wire nuts so that another piece of wire can be added to be able to reach the breaker or the neutral bar?
A. Yes
In order that the connections inside an outlet box remain accessible, the NEC® permits a surface extension from a flush-mounted device box to be made by installing ___.
A. an extension ring -- shown here -- with EMT connected to any knockout
Cabinets and cutout boxes shall have ___ to accommodate all conductors installed in them without crowding.
A. approved space
Cablebus shall be installed only for ___ work.
A. exposed
Type TC power and control cable may be used ___.
A. in outdoor locations when supported by a messenger cable
For messenger-supported wiring, open wiring on insulations, or concealed knob-and-tube wiring, the conductors shall enter the box though ___.
A. individual holes
26 feet of Type AC cable is used to connect a 2 x 4 lay-in fluorescent luminaire to a "home run" box as shown above in Figure 208.2. Supports #1 & #2 are as far from the connectors as the NEC® permits. You will have to install ___ additional supports between #1 and #2.
A. more than 3
Where any of the single conductors installed in ladder or ventilated trough cable trays are 1/0 through 4/0 AWG, all single conductors shall be installed in ____ layer(s).
A. one
In walls or ceilings constructed of ___, it is acceptable to have the front edge of the box set back as much as 1/4 inch from the finish surface.
A. sheetrock
When working with energized circuits, safety-related work practices shall be employed to prevent electrical ___.
A. shock
NEC® Section 250.118 permits ___ to be used as an equipment grounding conductor.
A. the armor of Type AC cable
Per the NEC® which of the following bends are permitted in a conduit run between two junction boxes?
A. two 90s plus one-45° three-point saddle plus one-12° offset
Which of the following may not be used in damp or wet locations?
A. type AC armored cable
A two-gang box contains two 12/2 AWG w/ground NM cables connected to a duplex receptacle and two 14/2 AWG w/ground NM cables connected to a single-pole switch. The two-gang box also contains four clamps. What MINIMUM cubic inch volume does the box require?
B. 30 cu. in.
Calculating and providing the proper volume of a box is not always enough. Section ___ of the NEC® states outlet and device boxes shall be deep enough so that conductors will not be damaged when installing wiring devices or equipment.
B. 314.24
Angle pull dimensional requirements apply to junction boxes only when the size of conductors is equal to or larger than ___ AWG.
B. 4
Given: A metal junction box has 27 cubic inches and contains a total of six 12 AWG wires. Additional conductors size 10 AWG need to be added in the box. No grounding conductors, devices or fittings are contained in the box. What is the MAXIMUM number of 10 AWG conductors that may be added to this box?
B. 5
Refer to Figure 210.6, shown above. The conductors connected to the terminal lugs are 350 kcmil. The minimum wire bending space required at I is ___ inches. These lugs are of the lay-in type.
B. 5
Transformers should not be connected to circuits that have voltages more than ___% above the nameplate rating of transformer.
B. 5
For angle pulls of conductors 4 AWG and larger, the distance between raceway entries enclosing the same conductor must be at least ________ times the size of the larger raceway.
B. 6
The maximum cross-sectional area that can be occupied by conductor in a 40-foot run of conduit is 40% where the conduit contains ___ conductor(s).
B. 7
A ceiling fan that weighs ___ pounds or less can be supported by an outlet box that is identified for such use and has "maximum weight to be supported — 70 lbs" stamped into the box.
B. 70
When you are working inside a transformer, the transformer is permitted to be energized.
B. False
Where covered with stabilized sand to prevent physical damage, Type ___ cable is permitted to be directly buried in a trench underground.I. UF II. MI III. AC
B. I & II only
A 300-foot run of 800-amp busway is installed in a commercial warehouse building. The last 20' of the busway run is reduced to a bus rating of 200 amps. Which of the following best describes the requirement for installation of the smaller bus?
B. It must be protected by an overcurrent device.
Type ___ cable is a factory assembly of one or more insulated circuit conductors with or without optical-fiber members enclosed in an armor of interlocking metal tape or a smooth or corrugated metallic sheath.
B. MC
Before working on a transformer you must follow the Safe Work Practices in ___.
B. NFPA 70E
Refer to Figure 205.12. The equipment grounding conductor is run on the inside of the FMC and the length of the flex is 8 feet. Is this a Code violation?
B. No
SE cable used to supply ___ shall not be subject to conductor temperatures in excess of the temperature specified for the type of insulation involved.
B. appliances
FS, FD, and larger cast or sheet metal boxes ___ classified as conduit bodies.
B. are not
Type FCC cable is designed for installations under ___.
B. carpet squares
Type MC cable shall not be used where exposed to ___ conditions.
B. destructive corrosive
When working near exposed energized conductors, each employee shall use ___.
B. insulated tools
Rigid Metal Conduit (RMC) is generally made of galvanized steel or aluminum. Aluminum is considered to be a ___ metal.
B. nonferrous
Nonmetallic boxes shall be suitable for the lowest ___ conductor entering the box.
B. temperature- rated
A properly rated ___ must be used to confirm that the power is off before work is started on a transformer.
B. voltage sensing device
According to Table 4 in the NEC 2-1/2 inch FMC has a total area of 4.909 in2. A 12' run of this flex can be filled with conductors for several circuits. However, the maximum area that can be occupied by the circuit conductors is __ sq. in.
C. 1.963
In no case shall conductors in cablebus be smaller than _____ AWG.
C. 1/0
No conductor larger than ___ AWG shall be installed in a cellular concrete floor raceway without special permission.
C. 1/0
Where cables assemblies with nonmetallic sheathes are used, the seath shall extend not less than ___ inside the box and beyond any cable clamp.
C. 1/4"
The smallest (volume) junction box that can be used in the installation, shown above in Figure 208.33, is a ___. Conduits #1 and #4 each contain twenty-four 10 AWG wires. Conduits #2 and #5 each contain twelve 6 AWG wires. Conduits #3 and #6 each contain sixteen 8 AWG wires. All conductors are "wire nutted" inside the box. Additionally, each conduit contains a ground that is equal in size to the circuit conductors.
C. 10" x 10" x 4" deep
A string of 2' x 4' lay-in fluorescent luminaires is to be connected by "looping" the wiring method. Between luminaires, the raceway entries are 6' apart. The length of the cable (or raceway) from the box to the first luminaire is 7 feet. Figure 208.3 LFNC is the wiring method to be used above in Figure 208.3. The maximum distance permitted between support #1 and support #2 is ___ feet.
C. 3
Schedule 40 PVC is to be installed in a straight run between two junction boxes on the back exterior wall of a strip shopping center. The summertime temperature is 100°F and the wintertime temperature is -5°F. An expansion fitting would be required in this 80' run of PVC because it would expand ___ inches between winter and summer.
C. 3.408
Cabinets and cutout boxes shall be deep enough to allow the closing of the doors when ___-ampere branch-circuit panelboard switches are in any position, when combination cutout switches are in any position, or when other single-throw switches are opened as far as their construction permits.
C. 30
The NEC® states that contact of dissimilar metals be avoided where practicable. The Code reference that specifically permits steel threaded rigid couplings to be used with aluminum rigid metal conduit is ___.
C. 344.14
A 21/2" rigid metal conduit enters the back of a pull box that has a removable cover on the opposite side. The raceway encloses four 4/0 AWG THHN copper conductors and one 4 AWG equipment grounding conductor. The minimum depth (distance from the entry wall to the cover) for this pull box is ___ inch(es).
C. 4
Refer to Figure 210.6, shown above. The conductors connected to the terminal lugs are 4/0 AWG. The minimum wire bending space required at I is ___ inches. These lugs are NOT removable.
C. 4
Among the possible box assemblies the smallest permitted to contain the following is ___. Exterior MC cable connectors are used on the cables.One - 30 amp 240-volt single receptacle and One - 15 amp 120-volt single receptacleTwo - 10/2 with ground MC cables plus One - 14/2 with ground MC cable
C. 4 x 1-1/2 square box with a 5.0 cu. in. two-gang plaster ring
Conductor fill may be up to ___ percent of the cross-sectional area in underfloor raceways.
C. 40
In a 30-foot run of conduit containing one conductor the maximum cross-sectional area that can be occupied by the conductor is ___ %.
C. 53
What minimum standard size wireway, such as shown in Figure 208.61, is required to contain one hundred #8 THHN/THWN conductors?
C. 6" x 6"
In straight pulls, the length of the box shall be not less than ___ times the trade diameter of the largest raceway for conductors 4 AWG and larger.
C. 8
___ fittings and enclosures shall be permitted to be used with IMC. I. Steel II. Aluminum
C. Both I and II
Refer to Figure 208.14, shown above. The flexible wiring method between the time clock and the panel is permitted to be ___.I. 1/2" LFNC II. 1/2" LFMC III. 3/8" FMC
C. I or II only
___ cable shall be flame-retardant, moisture-resistant, fungus-resistant, and corrosion-resistant.
C. NMC
Electrical metallic tubing shall be constructed of any of the following except:
C. Red brass
Which of the following statements about the protection of nonmetallic sheathed cable from physical damage is correct?I. When passing through a floor the cable shall be enclosed in a pipe or conduit extending at least 6 inches above the floor.II. When run across the top of the floor joists in an accessible attic, the cable shall be protected by guard strips.
C. both I and II
Ceiling-suspended (paddle) fans are required to be installed on ___.
C. boxes marked as suitable for fan installation
In completed installations, each outlet box shall have a ___.
C. cover
Live parts to which an employee may be exposed shall be ___.
C. de-energized
___ shall be used to warn employees about electrical hazards that may endanger them. I. Safety signs II. Accident prevention tags
C. either I or II
Transformers are permitted to be installed and serviced by ___.
C. qualified persons
All cut ends of rigid conduit shall be ___.
C. reamed
Mineral-insulated, metal-sheathed cable shall be supported and secured at intervals not exceeding ____.
D. 6 feet
High Density Polyethylene conduit larger than ____ shall not be used.
D. 6 inch
An steel metal cable tray that is to be used as an equipment grounding conductor, with conductors protected by a 100A circuit breaker, must have a cross-sectional area of ____ square inches.
D. .40
A metal switch enclosure installed in a damp or wet location shall be spaced at least ___" off the mounting surface.
D. 1/4
The Code permits a ___" maximum space between the panel enclosure ("can") and the panel cover as shown above in Figure 210.12.
D. 1/4
The largest conductor permitted in 3/8" flexible conduit is ___ AWG.
D. 10
The current carried continuously in bare copper bars in auxiliary gutters shall not exceed ___ amperes per square inch.
D. 1000
Vertical runs of metal wireways shall be securely supported at intervals not exceeding ____ feet and shall not have more than one joint between supports.
D. 15
No additional support is required for this installation (the earth can support the conduits) if the conduit length from the finish surface (dirt here) to the box is ___ inches or less.
D. 18
RMC is the wiring method used for the illustration shown below. The conduits are threaded wrenchtight into the entries in the bottom of the "bell" box. No additional support is required for this installation (the earth can support the conduits) if the conduit length from the finish surface (dirt here) to the box is ___ inches or less.
D. 18
Nonmetallic surface extensions with one or more extensions shall be permitted to be run in any direction from an existing outlet, but not on the floor or within ___ inches from the floor.
D. 2
The nominal gas pressure for IGS cable insulation shall be ___ pounds per square inch gauge.
D. 20
When conduit nipples having a maximum length not to exceed ___ inches are installed between boxes and similar enclosures, the nipples shall be permitted to be filled to 60% of their cross-sectional area.
D. 24
Where a 14" section of trade size 31/2 Schedule 40 PVC is installed between enclosures, no more than ___ 2/0 AWG THHN/THWN conductors can be installed.
D. 26
What minimum size schedule 80 PVC conduit is required for a 65' run? The conduit will contain three 350 kcmil, one 3/0, and one #2 THHN/THWN conductors.
D. 3
The calculated minimum width (left-to-right) of the pull box shown in Figure 208.53 is ___ inches.
D. 37
When calculating the conductor fill for strut-type channel raceway with external joiners, the raceway shall be permitted to be filled to ___ percent of the cross-sectional area.
D. 40
A flexible cord connection is made directly to the load end terminals of a busway plug-in device. The maximum length of this cord to a tension take-up device is ___ feet.
D. 6
Refer to Figure 210.6, shown above. The conductors connected to the terminal lugs are 4/0 AWG. The minimum wire bending space required at II is ___ inches. These lugs are of the lay-in type.
D. 6
Where run across the top of floor joists, or within ___ feet of the floor or floor joists across the face of rafters or studding, in an attic that has permanent stairs, nonmetallic sheathed cable must be protected by substantial guard strips that are at least as high as the cable.
D. 7
Splices and taps shall be permitted in surface nonmetallic raceways having a removable cover that is accessible after installation. The conductors, including splices and taps, shall not fill the raceway to more than ___ percent of its area at that point.
D. 75
What percent of a metal wireway cross section may be occupied by splices, taps, and conductors at any point?
D. 75%
When a single-gang nonmetallic outlet box does not have a clamp or connector, the maximum distance permitted between the box and the first strap in a NM cable installation is ___ inches.
D. 8
Type AC cable shall be permitted for branch circuits and feeders in ___.I. concealed workII. exposed workIII. hazardous locations
D. I & II only
Refer to Figure 208.35, shown above. Which industrial cover/box combination will violate the NEC®? All the conductors are 12 AWG.I. 4 x 11/2 square with 5.0 in3 industrial coverII. 411/16 x 11/4 square box with a 4.2 in3 industrial coverIII. 4 x 21/8 square box with a 3.6 in3 industrial cover
D. I only
Which of the following are permitted to be used to protect a GEC from physical damage?I. RMC II. Sch 40 PVC III. EMT
D. I or III only
Before turning on the power to the transformer, replace all ___. I. doors II. devices III. Covers
D. I, II & III
Compared to Schedule 40, Schedule 80 PVC ___.I. has a thicker wallII. can be used where subject to physical damageIII. has a smaller cross-sectional area for fill purposes
D. I, II, & III
Employees working in areas with potential electrical hazards shall use ___ to protect specific parts of the body.
D. PPE
The miniumum bending radius of Type P cable shall be:
D. adequate to prevent damage to the cable.
Which of the following could be used in a concrete slab?
D. all of these
A wall-mounted luminaire, such as a sconce, that weighs 4 pounds is permitted to be mounted to and supported by a ___.
D. any of these
When NM cable is run on the surface of ___ facing the attic, the cables require protection from physical damage by using substantial guard strips.
D. any of these
Covers of outlet boxes and conduit bodies having holes through which flexible cord pendants may pass shall be provided with approved ___ or shall have smooth, well-rounded surfaces upon which the cord may bear.
D. bushings
Type UF cable is permitted in which location?
D. corrosive environments
In NEC Chapter 3, Wiring Methods and Materials, requirements for splices and taps can be found in the _____ section.
D. xxx.56
An electrician needs to install a surface mounted, nonmetallic, weatherproof cabinet on the outside of a concrete block building. Since the cabinet must be mounted in a wet location, it must be mounted so there is at least ___ inch(es) of airspace between the cabinet and the wall.
E. 0
XHHW 500 kcmil conductors have an insulation that is ___ mm thick.
E. 1.65
Outlet boxes that do not enclose devices or utilization equipment shall have a minimum internal depth of ___ inch(es).
E. 1/2
The minimum CALCULATED dimension for "width" shown in Figure 208.55 is ___ inches.Conduit G = 2" Conduit H = 21/2" Conduit J = 11/2" Conduit K = 2"Conduit L = 1" Conduit M = 11/2" Conduit N = 2"
E. 20
Figure 124.103 You will need to gang together two single-gang (metal) switch (device) boxes to install the switches shown here. All connectors are the exterior type. Two cables are run from the switch boxes up to the ceiling-mounted heat/vent/light/night light unit. The wiring method used in Figure 124.103 is 14 AWG MC cable. Which of the switch boxes listed below is the smallest you can use and not violate the NEC®? Note: Each cable DOES contain an EGC but for clarity the equipment grounding conductors are not shown in the drawing.
E. 3 x 2 x 23/4
The calculated minimum height (top-to-bottom) of the pull box shown in Figure 208.53 is ___ inches. The conduits considered for this calculation contain conductors that enter this side and exit the adjacent side.
E. 33
The cross-sectional area of a 4 AWG BARE copper conductor is ___ cmils.
E. 41740
The minimum CALCULATED dimension for "height" shown in Figure 208.54 is ___ inches. All conductors enter the left size of the pull box and exit the bottom.
E. 44
In pull boxes or junction boxes having any dimension over ___ ft, all conductors shall be cabled or racked up in an approved manner.
E. 6
Busways shall be permitted to be extended vertically through dry floors if totally enclosed (unventilated) where passing through and for a minimum distance of ___ above the floor to provide adequate protection from physical damage.
E. 6 feet
Which of these trade size 11/4 raceways has the smallest cross-sectional area?
E. Schedule 80 PVC
The minimum size conductor permitted in commercial buildings for branch circuits up to and including 2000 volts is ___ AWG.
A. I or II only
According to the NEC® an 8 AWG bare stranded copper conductor has a cross-sectional area of ___ square inches.
B. .017
Which of the statements below is true?
B. An 8 AWG conductor has a greater resistance per foot than a 6 AWG conductor.
Do not use a ladder that is ___. I. defective II. set up improperly III. broken
B. I, II or III
Which of the drawings, shown above in Figure 207.12, fails to satisfy the NEC® requirements for conductor length in boxes?
B. II & III only
Which 2 AWG conductor has a lower resistance?
B. copper
Under certain conditions, the uninsulated conductor in nonmetallic-sheathed cable ___ permitted to be used as a current-carrying conductor ("hot" or neutral). Note: NM cable is not permitted to be used as service-entrance cable.
B. is not
When several AC, MC, or NMC cables are installed next to each other in a bundle, the conductors in the cables are able to carry ___ current than if the cables were separated.
B. less
Where two internal cable clamps are present in a box, a ___ conductor volume allowance will be counted towards the box fill calculation, based on the largest conductor in the box.
B. single
The ___ rating of a conductor is the maximum temperature, at any location along its length, that the conductor can withstand over a prolonged period of time without serious degradation.
B. temperature
Which of the following THHN/THWN copper conductors is the smallest size permitted for a 150 A feeder to a subpanel for an addition to an existing dwelling? The feeder originates in the 120/240-volt, 1-ph, 3-wire service panel in a home.
C. 1/0
Which of the following THHN/THWN copper conductors is the smallest size permitted for a feeder where a 150 A breaker protects the feeder? The feeder originates in the 120/240-volt, 1-ph, 3-wire service panel in a bakery.
C. 1/0
How much current can each conductor carry? Six, current-carrying 250 kcmil conductors are run in a pipe that is located in a 129°F ambient temperature location? The 75°C OCPD terminations are far away from the high temp area.
C. 176
Refer to Figure 204.3. The wire to Load #3 is 6 AWG, the wire to Load #2 is 1 AWG, and the wire to Load #1 is 2/0 AWG. Each of the loads is 3Ø, 3-wire. In the conduit with 9 conductors, how much current can the wire to Load #3 carry in the high-temperature area where the temperature is 121°F?
C. 43
For a raceway containing 30 current carrying conductors, the ampacity of each conductor shall be reduced to ___ percent of that for a single conductor.
C. 45
Where splices, angle or U pulls are made, the distance between each raceway entry inside the box and the opposite wall shall not be less than ___ times the trade size of the largest raceway, plus the trade size of all other raceways entering on the same wall in the same row.
C. 6
Where a cable or raceway-type wiring method is installed through bored holes in joists, rafters, or wood members, holes shall be bored so that the edge of the hole is not less than ____ from the nearest edge of the wood member.
D. 1 1/4 inch
In a wall made of noncombustible material, cabinets shall be installed so that the front edge of the cabinet is not set back from the finished surface more than ____.
D. 1/4 inch
Except where specifically referenced elsewhere in the Code, Article 312 does not apply to equipment operating at over ___volts.
D. 1000
Determine the maximum current-carrying capacity for each conductor when four 1/0 AWG THW current-carrying copper conductors are installed in a common raceway with an ambient temperature of 86 degrees F.
D. 120 amperes
According to the NEC®, the smallest size permitted for branch circuit conductors suitable for supplying other than cooking appliances is ___ AWG.
D. 14
The maximum temperature rating of a THHN conductor is ___°F in a dry location.
D. 194
Refer to Table 8 in Chapter 9 in the NEC®. The ___ of a conductor is measured in mm or in.
E. diameter
Underground service conductors that are not encased in concrete and that are buried _____ or more below grade shall have their location identified by a warning ribbon that is placed at least 12 inches above the underground installation.
A. 18 inches
A feeder needs to be installed to supply power to a load that will draw 900 amps. The circuit breaker will be rated at 900 amps. There will be 4 parallel conduits run for the feeder. You will need to install at least ___ AWG or kcmil conductors in each conduit.
A. 4/0
A flush-mounted well light is located in the corner of a sidewalk at a house as shown in Figure 121.211. The sidewalk is 3" thick and Schedule 40 PVC will be installed for the power. This 20-amp, 120-volt circuit is GFCI protected. In inches, what is the minimum depth from the top of the conduit to the top of the sidewalk?
A. 6
Which of the drawings, shown above in Figure 207.12, satisfies the requirements of the NEC® for conductor length in boxes?
A. I & IV only
Suffixes that designate the number of conductors within a cable include ___.I. D - two insulated conductors laid parallelII. M - two or more insulated conductors twisted spirallyIII. T - two or more insulated conductors twisted in parallel DMT
A. I or II only
When connections are made in the white wire to receptacles in a multiwire branch circuit, they are required to be ___.
C. made with a pigtail to the silver terminal
All metal raceways, cable armor, fittings, cabinets, and other metal enclosures for conductors must be ___ joined together to form a continuous electrical conductor.
C. metallically
For straight pulls of 2 AWG conductors through junction box, the length of the box shall be at least ___ times the size of the largest raceway.
D. 8
Type THW insulation has a ___ degree C rating for use in wiring through fixtures.
D. 90
When doing voltage-drop calculations, where is the cross-sectional area in circular mils located?
D. Chapter 9, Table 8
Bushings have been installed on all the conduits entering the box shown above in Figure 207.10. Where Conduit X contains 4 AWG, Conduit Y contains 2/0 AWG, and Conduit Z contains 1 AWG conductors, the NEC® requires ___ to have a bushing.I. Conduit X II. Conduit Y III. Conduit Z
D. I, II & III
Which of the following about the equipment grounding conductor is true?I. It does not count as a current-carrying conductor.II. A bare, covered or insulated conductor shall be permitted.III. For conduit fill, each grounding conductor counts as one conductor.
D. I, II & III
The parallel conductors in each phase or neutral shall ___.I. have the same insulation type and conductor materialII. be the same size in cmaIII. be the same length and be terminated in the same manner
D. I, II, and III
Which of the following conductor insulations is oil resistant?
D. MTW
IMC is the wiring method installed beneath the grassy area shown above in Figure 207.15. The minimum dimension permitted for Y is ___ inches.
A. 6
Refer to Table 8 in Chapter 9 in the NEC®. The ___ of a conductor is measured in mm2, circular mils, or in2.
A. area
Conductors in raceways must be ___ between outlet devices, and there shall be no splices or taps within the raceways.
A. continuous
Conductors with thermoplastic and fibrous outer braid Type TBS insulation are used for wiring ___.
A. switchboards only
A cable, raceway, or box, installed in exposed or concealed locations under metal-corrugated sheet roof decking, shall be installed and supported so there is not less than ______ measured from the lowest surface of the roof decking to the top of the cable, raceway, or box.
C. 1 1/2 inch
The minimum size THWN/THHN aluminum conductor permitted to serve a 95 amp load that will operate continuously is ___ AWG.
C. 1/0
The circular mil area of a 12 AWG conductor is ___.
C. 6530
What is the insulation temperature rating of type THWN wire in a wet location?
C. 75°C
The ampacity of conductors is derated when the ambient temperature exceeds ___ºF.
C. 86
How many 12 AWG conductors are permitted to be put in a 4-11/16" x 1-1/2" square box?
C. 9
4 AWG conductors can be spliced inside an LB type conduit body using ___.I. crimp connectors II. screw-type splice connectors III. wire nuts
C. I or II or III
In a 480/277-volt, 3Ø, 4-W panel, a wire connected to breaker 41 is permitted by the NEC® to be ___ in color. A 42-circuit panelboard is shown above. I. yellow II. blue III. orange
C. I or II or III
Which of the following are permitted to be buried in a trench underground? The wiring will be covered with stabilized sand to prevent physical damage.
C. Type MI cable
Where multiwire branch circuits are connected to breakers in a 277/480-volt, 3Ø, 4-wire panel, the neutral has to be counted as a current-carrying conductor (when applying ampacity correction factors) where the connected loads consist of ___ lighting.
C. both a & b
Conductor sizes are given in AWG or ___.
C. circular mils
When a device box contains a duplex receptacle, a ____ volume allowance is to be counted for the device.
C. double
To avoid heating problems due to induction, the Code generally prohibits installing a single conductor of an alternating-current (ac) system in a metallic raceway. Which of the following single conductors of an ac system is permitted to be installed by itself in a metallic raceway?
C. grounding electrode conductor
Dual-rated THHN/THWN conductors have an insulation that permits installation in ___ locations.
D. any of these
Insulated conductors used in wet locations shall ___.
D. any of these
Materials or trash left carelessly on the floor or stairs can cause ___.
D. any of these
___ shall be guarded to protect employees from falling into or through these openings.
D. any of these
What is not a factor when calculating voltage drop?
D. size of the conduit
Schedule 40 PVC is the wiring method installed beneath the grassy area shown above in Figure 207.15. A 120-volt circuit is fed from a 15-Amp GFCI breaker in the restaurant. The minimum dimension permitted for Y is ___ inches.
E. 18
Refer to Figure 207.19, shown above, where luminaires have been installed along a driveway to a single-family ranch home. Type UF cable is the wiring method installed between the luminaires and along the side of the drive. The minimum dimension permitted for Y along the side of the driveway is ___ inches.
E. 24
A service lateral is to be installed as direct-buried cable in the bottom of a trench that is 42 inches below finish grade. The trench is to be filled with dirt only. A warning ribbon is required to be installed in the trench at a maximum depth of ___ inches below finish grade.
E. 30
Fittings and connectors shall be used only with the specific wiring methods for which they are ___.I. approved II. designed III. listed
E. II & III only
Refer to Figure 207.17, shown above. The NEC® cover requirements for the underground conduit in Area B are taken from the row in Table 300.5 entitled ___.
E. In or under airport runways, including adjacent areas where trespassing prohibited