Deck 4: Branch Circuits

Question 1

Count the neutral conductor of a 4-wire, 3-phase, wye-connected circuit when the major portion of the load is electric discharge lighting (fluorescent, mercury vapor, high-pressure sodium, etc.), data processing, and other loads where the neutral conductor carries current.

A)grounding
B)traveler
C)third harmonic
D)unbalanced

Answer 1

C

Question 2

Multioutlet branch-circuit ratings are limited to 15-, 20-, 30-, 40-, and 50-ampere except on premises, where they may have a higher rating.

A)government
B)residential
C)commercial
D)industrial

Answer 2

D

Question 3

NEC Table 310.15(B)(16) places the wires available for building construction into two categories: and aluminum.

A)copper
B)gold
C)silver
D)platinum

Answer 3

A

Question 4

If the ambient temperature anywhere along the length of a raceway is less than 78 degrees F or higher than degrees F, the ampacity of the conductors in the raceway, or cable, must be modified by a correction factor.

A)80
B)84
C)86
D)90

Question 5

When sizing conductors and overcurrent protection, you must take 100 percent of the noncontinuous loads plus percent of the continuous loads.

A)75
B)80
C)100
D)125

Question 6

What is thermoset insulation?

Question 7

On what is the resistance of a conductor dependent?

Question 8

Several factors or conditions can cause conductors to overheat, but often overlooked is the possibility of .

A)induction heating
B)ambient temperature
C)the size of conductors
D)grounding

Question 9

Whenever a grouping of more than current-carrying conductors exists, an adjustment factor from NEC Table 310.15(B)(3)(a) must be applied.

A)two
B)three
C)four
D)five

Question 10

In general, the letter-type designation R formerly referred to a -based covering and now indicates thermoset insulation.

A)rhodium
B)rubidium
C)rayon
D)rubber

Question 11

The allowable ampacity of a 4 AWG THHN conductor is 95 amperes.If we have four 4 AWG THHN conductors, what is the adjusted ampacity?

A)48
B)63
C)76
D)95

Question 12

An exception to the rule where two different temperatures are encountered for the same conductors permits the application of the higher ampacity (lower temperature) if the length of the conductors that enter a higher temperature is not more than 10 ft (3.0 m) or not more than 10% of the total circuit length.

A)circuit derating
B)ampacity derating
C)ampacity rating
D)flux rating

Question 13

When all conductors of the same alternating-current circuit are in the same raceway, the magnetic flux around each conductor the magnetic flux of the other circuit conductors.

A)adds to
B)cancels out
C)reverses
D)doubles

Question 14

Although several different types of insulation are listed in the NEC, there are only three different temperature ratings: 60 degrees C, 75 degrees C, and degrees C.

A)80
B)85
C)90
D)110

Question 15

Where would insulation with high-temperature rating be needed and why?

Question 16

Metal raceways not properly grounded could become " " and present a shock hazard.

A)branched
B)live
C)shorted
D)charred

Question 17

For motors, the OCPDs are .

A)reverse-time fuses
B)inverse-time fuses
C)inverse-time circuit breakers
D)reverse-time circuit breakers

Question 18

During the process of laying out an electrical system, when are branch circuits assigned?

Question 19

How does oxidation affect aluminum conductors, and how can this be averted?

Question 20

Law proves that in a given circuit, the higher the impedance, the lower the current flow.

A)Ohm's
B)Watt's
C)Faraday's
D)Maxwell's