Deck 9: Using Wire Tables and Determining Conductor Sizes

Question 1

A circular mil is the ____ of the wire in mils squared.

A) area
B) circumference
C) diameter
D) radius

Answer 1

C

Question 2

A device that measures insulation resistance in millions of ohms is called a(n) ____.

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

Answer 2

B

Question 3

Which of the following conditions must be met before conductors are permitted by the NEC to be run in parallel?

A) The conductors must be the same length
B) One conductor must be copper and the other must be aluminum
C) The conductors must have the same circular mil area
D) All of the above
E) a and c only

Answer 3

E

Question 4

When determining the conductor size for a particular application, you are determining the maximum current a conductor can carry.

Question 5

A location that is subject to saturation by water is called a ____ location.

A) damp
B) dry
C) wet

Question 6

When selecting conductors for a particular application, the ambient temperature correction factors note need not be considered.

Question 7

The maximum amount of voltage drop permitted in a circuit is ____% of the applied voltage.

A) 0
B) 3
C) 6
D) 9

Question 8

Which of the following are included in NEC Table 310.13?

A) Insulation trade name
B) Conductor identification code letter
C) Maximum operating temperature of the conductor
D) All of the above
E) a and c only

Question 9

The conductors listed in NEC Tables 310.18 and 310.19 are generally used for ____ temperature locations.

A) high
B) low
C) all
D) cold

Question 10

A location that is not normally subject to dampness or wetness is called a ____ location.

A) damp
B) dry
C) wet

Question 11

When using a megger to test a circuit for grounds or shorts, the meter should be set ____.

A) lower than the circuit voltage
B) at the circuit voltage
C) slightly higher than the circuit voltage
D) a and b only
E) b and c only

Question 12

A location that is covered and not likely to be saturated by water is a ____ location.

A) damp
B) dry
C) wet

Question 13

When determining conductor size for an area where ambient temperature is a concern, you must divide the needed current by the correction factor.

Question 14

NEC® 110.14(C) states that the temperature rating of a conductor must be selected so as not to exceed the lowest temperature rating of any connected conductor, termination or device.

Question 15

When a three-phase installation is to be run in conduit, the power conductors ____.

A) must be run with each phase in its own conduit
B) must be run with one phase in each conduit
C) can be run in any manner

Question 16

In some cases, such as for long wire runs or for the windings of transformers and motors, the electrician must be able to determine the correct conductor size by computing the ____ of the conductor.

A) wattage
B) maximum voltage drop
C) resistance
D) both b and c

Question 17

Article ____ of the National Electrical Code deals with conductors used for general wiring.

A) 210
B) 250
C) 310
D) 410

Question 18

A megohmmeter can produce voltages that range from 250 V to ____ V.

A) 5,000
B) 10,000
C) 25,000
D) 50,000

Question 19

The temperature coefficient can be used to determine the resistance of a material at different temperatures.

Question 20

Which of the following conductors has the least resistance per mil foot at 20 degrees C?

A) Aluminum
B) Copper
C) Gold
D) Silver

Question 21

____________________ currents are currents that are induced into metals.

Question 22

A copper conductor will have ____________________ resistance than an aluminum conductor of the same size and length.

Question 23

The largest AWG size is ____________________, which has an area of 211,600 circular mills.

Question 24

AWG stands for ______________________________ which is the standard for determining wire size.

Question 25

If a conductor is to be installed in an area where the ambient temperature is not 86 degrees F, the _________________________ chart located at the bottom of NEC T310.16 is used to help determine the proper size conductor.

Question 26

When determing wire size, first remove the wire's ____________________.

Question 27

A(n) _________________________ is an English measure for determining the cross-sectional area of round wire.

Question 28

A wire's ability to carry current is known as its ____________________.

Question 29

For almost all applications, an electrician will use the ______________________________ to determine the correct conductor size.

Question 30

The gauge ____________________ is important for determining the current carrying capacity of a conductor.

Question 31

____________________ is the nonconductive covering around a wire that helps determine the amperage and voltage rating of the wire.

Question 32

____________________ are used when it is necessary to bury a group of electrical ducts or cables in the ground and maintain a separation between ducts or cables of at least 7.5 inches.

Question 33

A ____________________ is a piece of wire one foot long and one mil in diameter.

Question 34

Gauge sizes are determined by the number of ____________________ necessary to produce a given diameter or wire.

Question 35

To test wire insulation, a special type of ohmmeter called a ____________________ is used.

Question 36

The largest solid conductor listed in the wire tables is #____ AWG.

A) 12
B) 10
C) 8
D) 6

Question 37

The temperature of the surrounding air is called the ____________________ air temperature.

Question 38

A ____________________ circuit exists when there is a current path between conductors.

Question 39

If more than three conductors are to be used in a raceway, the ampacity of the conductors must be ____________________ because of heat buildup in the raceway.

Question 40

In practical applications, it is sometimes desirable to use ____________________ conductors instead of extremely large conductors.

Question 41

The NEC® defines a(n) ____________________ load as one where the maximum current is expected to continue for three hours or more.