Deck 11: Using Wire Tables and Determining Conductor Sizes

Question 1

What is the nonconductive covering around a wire?

A) insulation
B) conductor
C) duct bank
D) raceway

Answer 1

A

Question 2

A piece of wire that is one mil in diameter and one foot long is one mil-foot.

Answer 2

True

Question 3

The insulation used on conductors cannot operate in all possible temperatures. The highest allowable temperature is called the _____ temperature.

A) maximum operating
B) minimum operating
C) ambient
D) correction

Answer 3

A

Question 4

When a conductor is very large it may become necessary to connect them in _____.

A) parallel
B) series

Question 5

In the National Electrical Code^® , the current carrying abilities of conductors are called the _____.

A) ampacities
B) insulations
C) inductances
D) ambients

Question 6

The National Electrical Code^® _____ contains tables dealing with conductors for general wiring.

A) 300
B) 310
C) 100
D) 110

Question 7

All insulations perform equally well in dry, damp, and wet locations.

Question 8

Materials that increase their resistance with an increase in temperature have a _____ coefficient of temperature.

A) positive
B) negative

Question 9

The ambient air temperature considered in relation to a conductor ampacity is the temperature of the _____.

A) conductor
B) insulation
C) raceway
D) surrounding air

Question 10

The unit circular mil is equal to the _____.

A) radius of the wire in mils
B) diameter of the wire in mils
C) radius of the wire in mils squared
D) diameter of the wire in mils squared

Question 11

In the American Engineers Handbook , the standard temperature of material resistance is _____.

A) 20°C
B) 30°C
C) 40°C
D) 50°C

Question 12

The ____________________ was standardized in 1857 and is used mainly in the United States for the diameters of round, solid, nonferrous electrical wire.

Question 13

There are two conductors, a red and a blue installed in metallic conduit. You are using a MEGGER to test for grounds. How should the two leads of the MEGGER should be connected?

A) one to the blue lead and one to the conduit
B) one to the red lead and one to the conduit
C) one to the blue lead and one to the red lead
D) both a and b above

Question 14

There are two conductors, a red and a blue installed in metallic conduit. You are using a MEGGER to test for shorts. How should the two leads of the MEGGER should be connected?

A) one to the blue lead and one to the conduit
B) one to the red lead and one to the conduit
C) one to the blue lead and one to the red lead
D) both to the conduit

Question 15

If there are more than _____ conductors in a raceway, the ampacity of the conductors must be derated.

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

Question 16

A wire that has a diameter of 162 mils has an area of _____ circular mils.

A) 162
B) 26,244
C) 20,162
D) 509

Question 17

To test wire insulation, a special type of ohmmeter called a(n) _____ is used.

A) MEGGER
B) wattmeter
C) ammeter
D) voltmeter

Question 18

The longer the conductor, the more _____ it will have.

A) diameter
B) resistance
C) voltage

Question 19

There are six current-carrying conductors in a raceway that is to be installed in an area with an ambient temperature of 90 ° F. It is necessary to _____.

A) apply a correction for the ambient temperature only
B) derate because of the number of conductors in the raceway only
C) correct for temperature and derate (because of the number of conductors)
D) no corrections or derates are required

Question 20

The ampacities listed in Table 310.15(B)(16)  are based on an ambient temperature of _____.

A) 194 ° F
B) 30 ° F
C) 140 ° F
D) 86 ° F

Question 21

The ampacities listed in the tables are based on a specified ambient temperature. If conductors are to be operated in a different ambient temperature than the temperature specified, a(n) ____________________ factor must be applied.