NAVEDTRA 14176A, NEETS Mod. 4, Ch. 1 Flashcards Preview

Luftfart Elektronik Techniker > NAVEDTRA 14176A, NEETS Mod. 4, Ch. 1 > Flashcards

Flashcards in NAVEDTRA 14176A, NEETS Mod. 4, Ch. 1 Deck (43)
Loading flashcards...
1

Which unit of measurement is used to determine the cross-sectional area of a square or rectangular conductor?

Square mil

2

What is the standard unit of measurement of a round wire cross-sectional area?

Circular mil

3

What can be done to increase the flexibility of wire?

Stranding

4

What is a heavy copper strap or bar that is used to connect several circuits together?

Bus bar

5

What is the resistance in ohms offered by a unit volume (the circular-mil-foot or the centimeter cube) of a substance to the flow of electric current?

Specific resistance

6

What is the reciprocal of conductivity?

Resistivity

7

What is the most common method of measuring wire size in the Navy?

American Wire Gauge (AWG)

8

What is a single slender rod or filament of drawn metal called?

Wire

9

Which type of wire is suitable for carrying an electric current?

Conductor

10

Which type of conductor is composed of a group of wires or of any combination of groups of wires?

Stranded

11

Which wire property is used to determine what size is needed for a given load, or current drain?

Current rating

12

What prepares tables showing the safe current ratings for sizes and types of conductors covered with various types of insulation? 


National Board of Fire Underwriters

13

What is the best conductor?

Silver

14

What are the two most commonly used conductors?

Copper and Aluminum

15

Only about what percent of the conductivity of copper does aluminum have?

60

16

What is the discharge of electricity from the wire when it has a high potential called?

Corona

17

What are generally referred to as "insulators" or "insulating material."?

Nonconductors

18

Insulation resistance along with what else are the two fundamental properties of insulating materials? 


Dielectric strength

19

What is the resistance to current leakage through the insulation materials called?

Insulation resistance

20

What can insulation resistance be measured with that wont damage the insulation?

Megger

21

What is the ability of an insulator to withstand potential difference?

Dielectric strength

22

What is normally used for low- or medium-range voltage?

Rubber insulation

23

Which standard has the National Electrical Code (NEC) adopted as the minimum requirements for rubber insulation as specified by Underwriters' Laboratories? 


Code-graded rubber

24

Latex rubber is a high-grade compound consisting of what percent of unmilled grainless rubber?

90

25

Which rubber compound does not carry the "R" designator for many of its applications?

Silicone

26

What is one of the most common types of plastic insulating materials?

Thermoplastic

27

What is cotton cloth that has been coated with an insulating varnish known as?

Varnished cambric

28

Varnished cambric and paper insulation for cables are the two types of insulating materials most widely used at voltages above how many volts?

15,000

29

What is a high-temperature insulation used extensively in aircraft and equipment installations?

Extruded polytetrafluoroethylene

30

How many degrees Celsius is Fluorinated Ethylene Propylene (FEP) rated at?

200