Nevada C-2D Low Voltage Contractor Examination

Which 2017 NEC article covers audio signal processing, amplification, and reproduction equipment, including permanently installed sound systems?

• AArticle 640
• BArticle 645
• CArticle 725
• DArticle 760

Which 2017 NEC article covers communications circuits such as telephone and similar premises communications wiring?

• AArticle 725
• BArticle 770
• CArticle 800
• DArticle 820

Under the 2017 NEC communications cable substitution hierarchy, which listed cable type is permitted as a substitute for Type CMR riser cable?

• AType CM
• BType CMG
• CType CMX
• DType CMP

Per 2017 NEC 800.48, unlisted outside-plant communications cable may enter a building for not more than which length, measured from the point of entrance, if it is kept out of risers and environmental-air spaces and is terminated on a listed primary protector or in an enclosure?

• A25 feet
• B50 feet
• C100 feet
• D10 feet

According to 2017 NEC 90.3, how does Chapter 8 (Communications Systems) apply relative to Chapters 1 through 7?

• AChapter 8 always modifies Chapters 1 through 4 the same way Chapters 5 through 7 do
• BChapter 8 is independent of Chapters 1 through 7 except where it specifically references…
• CChapter 8 applies only if the Authority Having Jurisdiction adopts it separately from the…
• DChapter 8 is informational only and is not enforceable

Which 2017 NEC optical fiber cable type is nonconductive and listed for use in ducts, plenums, and other spaces used for environmental air?

• AType OFNP
• BType OFCR
• CType OFNG
• DType OFNR

Under 2017 NEC 840.160, when communications cable also carries power to communications equipment at more than 60 watts, the installation must comply with which additional requirement?

• ASection 725.144, using communications cable in place of Class 2 or Class 3 cable
• BArticle 760 power-limited fire alarm rules
• CNo additional ampacity rule; any listed CM cable may carry unlimited power
• DArticle 690 photovoltaic rules

A 70-volt distributed sound system has ten loudspeakers. Each speaker transformer is tapped at 5 watts. Ignoring transformer insertion loss, what is the minimum amplifier output power required to drive the line at those taps?

• A35 watts
• B50 watts
• C70 watts
• D5 watts

What is the minimum size of a copper grounding conductor for a receiving-station antenna mast or antenna discharge unit under 2017 NEC 810.21?

• A12 AWG copper
• B10 AWG copper
• C6 AWG copper
• D14 AWG copper

Where a coaxial CATV cable with a metallic shield enters a building, 2017 NEC 820.93 generally requires which action at the building entrance?

• AGround the outer conductive shield of the coaxial cable
• BInstall a Class 1 power-limited transformer on the shield
• CReplace the coaxial cable with Type NM-B inside the wall
• DLeave the shield floating so noise does not enter the premises wiring

Which 2017 NEC CATV coaxial cable type is listed for use in ducts, plenums, and other spaces used for environmental air?

• AType CATV
• BType CATVR
• CType CATVX
• DType CATVP

What is the minimum size of the copper bonding conductor or grounding electrode conductor for a communications cable primary protector under 2017 NEC 800.100?

• A16 AWG copper
• B14 AWG copper
• C8 AWG copper
• D18 AWG copper

A large bundle of 4-pair Class 2 data cables will carry Power over Ethernet above 60 watts. Which 2017 NEC provision was added to limit conductor heating in that application?

• ASection 725.144 and Table 725.144, or listed Class 2-LP / Class 3-LP cable marked with a…
• BArticle 430 motor full-load current tables
• CSection 250.66 grounding-electrode conductor table
• DTable 310.15(B)(16) alone, using the 60°C column for 14 AWG

Under 2017 NEC 800.25, what must be done with accessible abandoned communications cable?

• AIt shall be removed, except cable that is tagged for future use and not abandoned
• BIt must be painted red and left in the ceiling for the next tenant
• CIt may be abandoned in place if it is Type CMX
• DIt may remain indefinitely if it is still on the original reel tag

Unless specifically permitted elsewhere, 2017 NEC 240.4(D) limits overcurrent protection for 12 AWG copper conductors to a maximum of:

• A20 amperes
• B25 amperes
• C30 amperes
• D15 amperes

A branch-circuit overcurrent device serving a continuous load must have a rating of not less than what percentage of that continuous load, per 2017 NEC 210.20(A)?

• A115 percent
• B125 percent
• C150 percent
• D100 percent

Per 2017 NEC 215.3, a feeder overcurrent device shall have a rating of not less than:

• A125 percent of the continuous load plus 100 percent of the noncontinuous load
• B80 percent of the sum of all connected loads
• CThe service-disconnect rating, regardless of feeder load
• D100 percent of the continuous load only

A feeder supplies a 40-ampere continuous load and a 20-ampere noncontinuous load. Using the general 2017 NEC 215.2(A)(1) and 215.3 method (assembly not listed for 100 percent rating), what is the minimum feeder conductor ampacity and minimum overcurrent-device rating?

• A60 amperes ampacity and a 60-ampere overcurrent device
• B70 amperes ampacity and a 70-ampere overcurrent device
• C80 amperes ampacity and a 100-ampere overcurrent device
• D48 amperes ampacity and a 50-ampere overcurrent device

The Informational Notes to 2017 NEC 210.19(A) and 215.2(A)(1) recommend that voltage drop not exceed which combination for reasonable efficiency?

• A3 percent on feeders or branch circuits and 5 percent total for feeders plus branch circu…
• B5 percent on the branch circuit and 10 percent total
• C10 percent on any 12-volt circuit and 3 percent on 120-volt circuits
• D1 percent on the branch circuit and 2 percent total

Which of the following is a standard overcurrent-device ampere rating listed in 2017 NEC 240.6(A)?

• A18 amperes
• B22 amperes
• C25 amperes
• D55 amperes

Under the 2017 NEC 230.71 six-disconnect rule, the service disconnecting means for each service permitted by 230.2 shall consist of not more than how many switches or sets of circuit breakers mounted in a single enclosure, in a group of separate enclosures, or in or on a switchboard or in switchgear?

• ATwo
• BFour
• CSix
• DEight

For a multiwire branch circuit, 2017 NEC 210.4(B) requires that the ungrounded conductors be provided with a means to disconnect them how?

• ASimultaneously at the point where the branch circuit originates
• BOnly at the last receptacle on the circuit
• COnly if the circuit supplies a motor
• DIndependently, so one hot can remain energized for troubleshooting

A copper feeder has a calculated ampacity of 62 amperes after all correction and adjustment. The load is not a motor and is not covered by a specific tap rule. What is the maximum standard overcurrent device permitted by the 2017 NEC 240.4(B) next-higher-standard-size permission (800 amperes or less)?

• A70 amperes
• B80 amperes
• C90 amperes
• D60 amperes

Article 100 of the 2017 NEC defines a continuous load as a load where the maximum current is expected to continue for how long?

• A30 minutes or more
• B1 hour or more
• C3 hours or more
• D24 hours

NEC 2017 110.9 requires equipment intended to interrupt current at fault levels to have an interrupting rating at nominal circuit voltage sufficient for which current?

• AThe current that must be interrupted, including the available fault current at the line t…
• BThe transformer primary full-load current only
• CFifteen amperes on every 120-volt branch circuit, regardless of available fault current
• DThe connected continuous load current

Eight current-carrying 12 AWG copper THHN conductors (90°C, Table 310.15(B)(16) ampacity 30 amperes) are installed in a single EMT. Ambient temperature is 30°C (86°F). After applying 2017 NEC Table 310.15(B)(3)(a) and the 240.4(D) small-conductor rule, what is the maximum standard overcurrent device permitted for each conductor used as a branch-circuit conductor?

• A20 amperes
• B25 amperes
• C30 amperes
• D15 amperes

Per 2017 NEC 230.70(A)(1), the service disconnecting means shall be installed at a readily accessible location either outside the building or structure or inside nearest the point of entrance of the service conductors. “In Sight From” in Article 100 means visible and not more than how far away?

• A10 feet
• B25 feet
• C50 feet
• D100 feet

A 16-ampere continuous load is supplied by a 120-volt branch circuit. Using the general 2017 NEC 210.19(A)(1) and 210.20(A) method, what is the minimum conductor ampacity and minimum overcurrent-device rating?

• A16-ampere ampacity and a 15-ampere overcurrent device
• B16-ampere ampacity and a 20-ampere overcurrent device
• C20-ampere ampacity and a 20-ampere overcurrent device
• D24-ampere ampacity and a 30-ampere overcurrent device

Using 2017 NEC 240.4(D) and the common 60°C column of Table 310.15(B)(16) for small copper conductors, which pairing is correct?

• A14 AWG = 15 A, 12 AWG = 20 A, 10 AWG = 30 A
• B14 AWG = 15 A, 12 AWG = 30 A, 10 AWG = 40 A
• C14 AWG = 25 A, 12 AWG = 30 A, 10 AWG = 40 A
• D14 AWG = 20 A, 12 AWG = 25 A, 10 AWG = 35 A

Under 2017 NEC 200.6, a grounded conductor 6 AWG or smaller shall be identified by a continuous outer finish of which color(s)?

• AWhite, gray, or three continuous white or gray stripes on other than green insulation
• BOrange
• CBare copper only, with no insulation color permitted
• DGreen, or green with one or more yellow stripes

Individually covered or insulated equipment grounding conductors 6 AWG and smaller shall have a continuous outer finish of which color under 2017 NEC 250.119?

• AGreen, or green with one or more yellow stripes
• BOrange
• CBlue
• DWhite or gray

Per 2017 NEC Table 310.15(B)(3)(a), what adjustment factor applies to the ampacity of 4 to 6 current-carrying conductors in a raceway or cable?

• A80 percent
• B70 percent
• C50 percent
• D40 percent

Seven current-carrying 10 AWG copper THHN conductors (90°C ampacity 40 amperes) share one raceway at 30°C. What is the adjusted ampacity of each conductor before applying 240.4(D)?

• A40 amperes
• B32 amperes
• C28 amperes
• D20 amperes

Under 2017 NEC 310.15(B)(5), when is a grounded (neutral) conductor counted as a current-carrying conductor for ampacity adjustment?

• ANever; neutrals are never current-carrying for adjustment purposes
• BOnly when it is 4 AWG or larger
• CWhen it carries only the unbalanced current from other conductors of the same circuit it…
• DAlways, because every white conductor carries current

According to 2017 NEC Chapter 9, Table 8, the circular-mil area of 12 AWG is:

• A6,530 circular mils
• B10,380 circular mils
• C16,510 circular mils
• D4,110 circular mils

A 120-volt single-phase branch circuit uses 12 AWG copper (6,530 circular mils) and carries 16 amperes for a one-way distance of 80 feet. Using VD = 2 × K × I × D / CM with K = 12.9 for copper, the voltage drop is closest to:

• A2.1 volts
• B3.2 volts
• C5.1 volts
• D8.0 volts

A 12-volt landscape lighting run uses 12 AWG copper (6,530 circular mils) and carries 8 amperes for 40 feet one way. Using VD = 2 × K × I × D / CM with K = 12.9, the voltage drop and percent drop are closest to:

• A0.40 volts (3.3 percent)
• B0.80 volts (6.7 percent)
• C1.26 volts (10.5 percent)
• D2.52 volts (21 percent)

If a white or gray conductor is used as an ungrounded conductor in a cable, 2017 NEC 200.7(C) requires that it be permanently reidentified at its terminations by coloring, marking tape, or other effective means. Which identification is required?

• AIt must be reidentified to indicate that it is an ungrounded conductor, and it shall not…
• BNo reidentification is required inside a cable
• CIt must be reidentified with three white stripes
• DIt must be reidentified green

Per 2017 NEC 310.106(C), conductors of which size and larger installed in a raceway must be stranded, unless specifically permitted elsewhere?

• A14 AWG
• B12 AWG
• C10 AWG
• D8 AWG

Type THHN insulation is recognized in 2017 NEC Table 310.104(A) / Table 310.15(B)(16) as having which maximum operating temperature?

• A60°C (140°F)
• B75°C (167°F)
• C90°C (194°F)
• D250°C (482°F)

NEC 2017 300.3(B) requires all conductors of the same circuit—including the grounded conductor and all equipment grounding conductors—to be installed in the same raceway, auxiliary gutter, cable tray, trench, cable, or cord, unless otherwise permitted. What is the primary electrical reason?

• ATo allow the neutral to be omitted if the run is short
• BTo satisfy a painting and identification rule in Article 200
• CTo reduce the amount of conduit purchased
• DTo keep inductive reactance low and ensure overcurrent devices and EGCs can perform durin…

A 20-ampere branch circuit uses 12 AWG copper ungrounded conductors (6,530 circular mils) and a 12 AWG copper EGC. The ungrounded conductors are increased to 10 AWG copper (10,380 circular mils) for voltage drop. Per 2017 NEC 250.122(B), the EGC must be increased to not smaller than:

• A8 AWG copper, one size larger than the new ungrounded conductors
• B6 AWG copper, the same size used to bond a ground rod
• C12 AWG copper, because Table 250.122 still shows 12 AWG for 20 amperes
• D10 AWG copper, in proportion to the circular-mil increase of the ungrounded conductors

Nevada C-2D Low Voltage classification work is limited to systems that use fiber optics or that do not exceed which voltage?

• A24 volts
• B50 volts
• C91 volts
• D150 volts

Which of the following systems is within the official Nevada C-2D Low Voltage scope?

• AFire detection and smoke-alarm systems under subclassification C-2C
• BUnlimited-voltage branch-circuit lighting and receptacle work under classification C-2
• CTelephone, sound, CATV, CCTV, satellite dish, instrumentation and temperature controls, c…
• DHigh-voltage utility distribution above 600 volts

Ohm’s law states which relationship among voltage (E), current (I), and resistance (R)?

• AE = I + R
• BE = I² / R
• CE = I / R
• DE = I × R

A listed Class 2 power supply delivers 24 volts DC to a control load of 1.5 amperes. What is the load power?

• A16 watts
• B24 watts
• C36 watts
• D48 watts