421

a. 65

A nipple contains four 6 AWG THW copper current-carrying conductors. The ampacity of each conductor would be ___ amperes. Select one: a. 65 b. 44 c. 55 d. 52.

e. 3

ENT shall be supported at least every ___ feet. Select one: a. 6 b. 10 c. 5 d. 4 1/ 2 e. 3

c. 2 1/ 2 in.

Five 1 AWG and five 3 AWG copper THW conductors are to be installed in a 20-foot length of IMC raceway. What is the minimum allowable trade size IMC required to contain these ten conductors? Select one: a. 2 in. b. 1 1/ 2 in. c. 2 1/ 2 in. d. 3 in.

c. suitable for use and arranged to drain

Raceways on the outside of a building shall be ___. Select one: a. watertight and arranged to drain b. weatherproof and covered c. suitable for use and arranged to drain d. rainproof and guarded

a. 18

Rigid Schedule 80 PVC is installed underground to supply a marque sign for a church. The PVC shall have a minimum burial depth of ___ inches where installed under a grassy area. Select one: a. 18 b. 24 c. 10 d. 6

c. ozone-resistant

Solid dielectric insulated conductors operated above 2000 volts in permanent installations shall have ___ insulation and shall be shielded. Select one: a. high-temperature b. cross-linked polyethylene c. ozone-resistant d. asbestos

a. 180

In vertical raceways, 3/0 AWG aluminum conductors must be supported if the vertical rise is greater than ___ ft. Select one: a. 180 b. 80 c. 10 d. 100 e. 30

a. gray

The color ___ may have been used in the past as an ungrounded conductor. Care should be taken when working on existing systems. Select one: a. gray b. orange c. white d. green

d. 75

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. Select one: a. 53 b. 40 c. 38 d. 75

d. all of these

The use of nonmetallic underground conduit with conductors shall be permitted ___. Select one: a. for direct burial underground installation b. encased or embedded in concrete c. in cinder fill d. all of these

e. II or III only

When two multiwire branch circuits from different systems are installed in the same raceway and the neutral from one system has an outer covering of white, the other circuit's neutral is permitted to have an outer covering of ___. I. white with green stripe II. natural gray III. white with colored stripe, other than green Select one: a. II only b. I or III only c. III only d. I only e. II or III only

d. exposed to sunlight

Where ___, nonmetallic wireway shall not be permitted unless marked for the use. Select one: a. used in exposed locations b. used in wet locations c. subject to corrosive vapors d. exposed to sunlight

d. induction

Where conductors carrying alternating current are installed in ferrous metal raceways, they shall be arranged so as to avoid heating the surrounding metal by ___. Select one: a. osmosis b. hysteresis c. convection d. induction e. conversion

c. THHW

Which of the following listed conductors has a greater ampacity when used in a dry location compared to when used in a wet location? Select one: a. THW b. RHW c. THHW d. THWN

b. header duct

A(n) ___ is a transverse metal raceway for electrical conductors, furnishing access to predetermined cells of a precast cellular concrete floor, which permits installation of conductors from a distribution center to the floor cells. Select one: a. mandrel b. header duct c. underfloor raceway d. cellular raceway

c. 12

According to the Code, where not placed on racks or brackets, conductors on poles shall be separated by not less than ___ inches. Select one: a. 18 b. 6 c. 12 d. 24

d. all of these

As shipped from the manufacturer, rigid metal conduit shall ___. Select one: a. be in standard lengths of 10 feet b. include a coupling on each length c. be threaded on each end d. all of these

a. all conductors shall have an insulation rating equal to the maximum circuit voltage applied to any conductor in the conduit

Conductors of AC or DC circuits rated 600 volts or less shall be permitted to occupy the same conduit if ___. Select one: a. all conductors shall have an insulation rating equal to the maximum circuit voltage applied to any conductor in the conduit b. all conductors have a 600-volt insulation rating c. a dividing barrier in the raceway separates the AC and DC circuit conductors d. none of these; AC and DC conductors are not permitted in the same raceway

a. in high temperature areas

Liquidtight flexible metal conduit shall not be permitted ___. Select one: a. in high temperature areas b. where installation requires flexibility or protection from liquids, vapors or solids c. in exposed and concealed work d. in hazardous locations

e. any of these

Supporting rigid metal conduit by a bored or punched hole in a ___ meets the support requirements of the NEC®. Select one: a. rafter b. wall c. truss d. framing member e. any of these

a. 3/ 4

The maximum size of flexible metallic tubing is trade size ___. Select one: a. 3/ 4 b. 4 c. 2 d. 6 e. 1

b. 14

The minimum size conductor permitted in commercial buildings for branch circuits under 600 volts is ___ AWG. Select one: a. 10 b. 14 c. 8 d. 12

c. .0209

What is the area in square inches for a 14 AWG RHW without outer covering? Select one: a. .0135 b. .0327 c. .0209 d. .0230

a. 2 in.

All of the following copper wires are to be installed in an electrical metallic tubing that is 10 ft. long. * 24 - 10 AWG TW * 10 - 10 AWG THW * 14 - 12 AWG THHN Determine the minimum trade size of EMT required. Select one: a. 2 in. b. 3 1/ 2 in. c. 3 in. d. 2 1/ 2 in.

d. 20

For industrial machinery, straight exposed vertical risers of intermediate metal conduit with threaded couplings are permitted if supported at the top and bottom no more than ___ feet apart. Select one: a. 12 b. 10 c. 15 d. 20

b. 3'

Horizontal installations of nonmetallic wireways shall be supported at distances not exceeding ___, unless listed for other support intervals. Select one: a. 2' b. 3' c. 5' d. 4'

d. 1/ 4 in.

In the frequently washed indoor areas of a car wash, metal conduit and metal panelboards shall be mounted with a ___ space between the wall and the conduit or panelboard when the equipment is installed exposed. Select one: a. 3/ 4 in. b. 1/ 8 in. c. 1/ 2 in. d. 1/ 4 in.

c. 1/2" to 4"

Minimum and maximum sizes of EMT are ___ except for special installations. Select one: a. 1/2" to 3" b. 5/16" to 3" c. 1/2" to 4" d. 3/8" to 4"

a. 90º

Most conduit and tubing type raceways have a maximum equivalent of four ___ bends. Select one: a. 90º b. 30º c. 45º d. 180º e. 360º

c. 1000

The current carried continuously in bare copper bars in auxiliary gutters shall not exceed ___ amperes per square inch. Select one: a. 560 b. 800 c. 1000 d. 700

c. 10

The largest conductor permitted in 3/ 8" flexible conduit is ___ AWG. Select one: a. 12 b. 14 c. 10 d. 16

d. all of these

The parallel conductors in each phase, neutral, or equipment grounding conductor shall ___. Select one: a. be terminated in the same manner b. have the same circular mil area and insulation type c. be the same length and conductor material d. all of these

d. all of these

The use of PVC conduit shall be permitted when ___. Select one: a. installed in cinder fill b. directly buried underground c. encased or embedded in concrete d. all of these

c. listed for use in wet locations

Threadless couplings for rigid metal conduit installed in wet locations shall be ___. Select one: a. of steel construction b. enclosed in concrete c. listed for use in wet locations d. of the set screw type

d. MTW

Which of the following conductor insulations is oil resistant? Select one: a. THWN b. TW c. TFE d. MTW

c. Either a or b

___ fittings and enclosures shall be permitted to be used with IMC. Select one: a. Steel b. Aluminum c. Either a or b d. Neither a nor b

a. are

Circuit conductors that operate at 277 volts AC (with insulation rated for 1000 volts or less) ___ permitted to occupy the same enclosure or raceway with 48-volt DC conductors that have an insulation rating of 300 volts. Select one: a. are b. are not

b. expansion fittings

Raceways shall be provided with ___ where necessary to compensate for thermal expansion and contraction. Select one: a. expansion couplings b. expansion fittings c. bonding jumpers d. none of these

b. 7

The maximum distance between supports for 4" PVC is ___ feet. Select one: a. 20 b. 7 c. 10 d. 16 e. 5

e. 3

Where flexibility is necessary, securing of trade size 1-inch liquidtight flexible metal conduit is not required for lengths not exceeding ___ feet at terminals. Select one: a. 2 b. 2 1/ 2 c. 6 d. 4 e. 3

c. 15

Where electrical nonmetallic tubing is installed concealed in walls, floors, and ceilings in buildings exceeding three floors above grade, a barrier must be provided having a minimum ___-minute finish rating as listed for fire-rated assemblies. Select one: a. 10 b. 30 c. 15 d. 5

b. suitable for use

Where exposed to the weather, raceways shall be ___ and arranged to drain. Select one: a. rainproof b. suitable for use c. watertight d. weatherproof

a. supported

Wiring methods installed behind panels that allow access, such as the space above a dropped ceiling, are required to be ___ according to their applicable articles. Select one: a. supported b. painted c. in a metal raceway d. all of these

c. 80 amperes

A conductor has a computed ampacity of 75 amps. What is the maximum standard ampere rating of the overcurrent protection device the NEC® permits to protect this circuit? This is not a motor circuit or part of a multioutlet branch circuit supplying receptacles. Select one: a. 85 amperes b. 75 amperes c. 80 amperes d. 70 amperes

a. 6 ft

A section of 3/ 8" flexible metallic conduit is permitted for tap conductors when connecting to light fixtures, provided the length of the flex does not exceed ___. Select one: a. 6 ft b. 4 ft c. 8 ft d. 3 ft

a. 80

A vertical run of 4/0 AWG copper conductors must be supported at intervals not exceeding ___ feet. Select one: a. 80 b. 100 c. 120 d. 40

d. any of these

Aluminum fittings and enclosures shall be permitted to be used with ___ conduit. Select one: a. polyvinyl chloride b. aluminum rigid metal c. steel rigid metal d. any of these

b. 1 AWG

Among the conductors listed below, all except ___ are permitted to be connected in parallel. Select one: a. 250 kcmil b. 1 AWG c. 1/0 AWG d. 2/0 AWG

d. 40

Conductor fill may be up to ___ percent of the cross-sectional area in underfloor raceways. Select one: a. 38 b. 55 c. 30 d. 40

c. 8

Conductors ___ AWG and larger shall be stranded when installed in raceways. Select one: a. 10 b. 6 c. 8 d. 4

b. continuous

Conductors in raceways must be ___ between outlet devices, and there shall be no splices or taps within the raceways. Select one: a. installed b. continuous c. in conduit d. copper

d. all of these

The ___ of conductors used in prewired manufactured assemblies of LFNC shall be identified by means of a printed tag or label attached to each end of the manufactured assembly. Select one: a. quantity b. type c. size d. all of these

c. .581

The allowable fill for an 1 1/ 4-inch Schedule 40 PVC with more than 2 conductors is ___ sq. in. Select one: a. .333 b. .495 c. .581 d. .794

d. voltage drop

The ampacities provided by the NEC® for conductors 0-2000 volts are based on temperature alone and do not take ___ into consideration. Select one: a. CMA b. insulation c. AWG d. voltage drop

c. 86

The ampacity of conductors is derated when the ambient temperature exceeds ___ºF. Select one: a. 72 b. 104 c. 86 d. 30

b. 20

The sum of the cross-sectional areas of all contained conductors at any cross section of a wireway shall not exceed ___ % fill. Select one: a. 40 b. 20 c. 100 d. 80 e. 75

b. serious degradation

The temperature rating of a conductor is the maximum temperature, at any location along its length, that the conductor can withstand over a prolonged time period without ___. Select one: a. a ground fault b. serious degradation c. tripping the breaker d. short circuiting

c. 50 amps

What is the ampacity of an 8 AWG XHHW copper conductor in a wet location? Select one: a. 45 amps b. 55 amps c. 50 amps d. 40 amps

b. 9

What is the maximum number of 1/0 THHN conductors allowed in a 3" × 3" sheet metal auxiliary gutter? Select one: a. 12 b. 9 c. 18 d. 21

a. 10

What is the maximum number of 4 AWG THHN conductors permitted in 1 1/ 2" rigid metal conduit? Select one: a. 10 b. 8 c. 6 d. 7 e. 11

d. 18 AWG

What is the minimum size fixture wire? Select one: a. 20 AWG b. 16 AWG c. 22 AWG d. 18 AWG

d. all of these

What length of nipple may utilize the 60% conductor fill? Select one: a. 12" b. 18" c. 24" d. all of these

c. 75%

What percent of a metal wireway cross section may be occupied by splices, taps, and conductors at any point? Select one: a. 40% b. 30% c. 75% d. 20%

b. tubular

In cellular concrete floor raceways, a "cell" shall be defined as a single, enclosed ___ space in a floor made of precast cellular concrete slabs, with the direction of the cell being parallel to the direction of the floor member. Select one: a. circular b. tubular c. hexagonal d. rectangular e. oval

d. 4 AWG

Insulated conductors smaller than ___, intended for use as grounded conductors of circuits, shall have an outer identification of white or gray color. Select one: a. 250 kcmil b. 2 AWG c. 1/0 AWG d. 4 AWG

c. 3 feet

Intermediate metal conduit shall be firmly fastened within ___ of each outlet box, junction box, device box, fitting, cabinet, or other conduit termination. Select one: a. 12 inches b. 2 feet c. 3 feet d. 18 inches

b. not be considered a splice or tap

Loop wiring shall ___ in a cellular metal raceway. Select one: a. be considered a splice or tap when used b. not be considered a splice or tap c. not be permitted d. be permitted on conductor sizes 10 AWG and smaller

d. shall be removed from the raceway

When an outlet from an underfloor raceway is discontinued, the sections of the circuit conductors supplying the outlet ___. Select one: a. shall be permitted to be reinsulated b. shall be handled like abandoned outlets on loop wiring c. shall be permitted to be spliced d. shall be removed from the raceway

c. should carry the unbalanced current in each ungrounded conductor

When balancing a 3-wire circuit, from a single-phase 230/115-volt system, the neutral conductor ___. Select one: a. should carry the sum of the currents in each ungrounded conductor b. is used only for grounding c. should carry the unbalanced current in each ungrounded conductor d. none of these

c. 18

When installed underground with only earth and grass as cover, polyvinyl chloride conduit must have a minimum of ___ inches of cover. Select one: a. 6 b. 12 c. 18 d. 24

d. 16 ft

When installing 2" rigid metal conduit with threaded fittings, the NEC® requires the maximum distance between supports to be no more than ___. Select one: a. 3 ft b. 5 ft c. 10 ft d. 16 ft

d. I or II only

Where moisture could enter a raceway and contact energized live parts, ___ are required at one or both ends of the raceway. I. seals II. plugs III. bushings Select one: a. I only b. II or III only c. II only d. I or II only e. I or III only

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. Select one: a. I & III only b. II & III only c. I only d. I, II & III