click below
click below
Normal Size Small Size show me how
NAVEDTRA 14176A
ET2 BIBS MAR 2017
Question | Answer |
---|---|
Which unit of measurement is used to determine the cross-sectional area of a square or rectangular conductor? | square mil |
What is the standard unit of measurement of a round wire-cross-sectional area? | circular mil |
What can be done to increase the flexibility of wire? | stranding |
What is a heavy copper strap or bar that is used to connect several circuits together? | bus bar |
What is the resistance in ohms offered by a unit volume of a substance to the flow of electric current? | specific resistance |
What is the reciprocal of conductivity? | resistivity |
What is the most common method of measuring wire size in the Navy? | American Wire Gauge (AWG) |
What is a single slender rod or filament of drawn metal called? | wire |
Which type of wire is suitable for carrying an electric current? | conductor |
Which type of conductor is composed of a group of wires or of any combination of groups of wires? | stranded |
Which wire property is used to determine what size is needed for a given load, or current drain? | current rating |
What is the best conductor? | silver |
What are the two most commonly used conductors? | copper and aluminum |
Only about what percent of the conductivity of copper does aluminum have? | 60% |
What is the discharge of electricity from the wire when it has a high potential called? | corona |
What are generally referred to as "insulators" or "insulating material"? | nonconductors |
Insulation resistance along with what else are the two fundamental properties of insulating materials? | dielectric strength |
What is the resistance to current leakage through the insulation material called? | insulation resistance |
What can insulation resistance be measured with that won't damage the insulation? | megger |
What is the ability of an insulator to withstand potential difference? | dielectric strength |
What is normally used for low or medium- range voltage? | rubber insulation |
Which rubber compound does not carry the "R" designator for many of its applications? | silicone |
What is one of the most common types of plastic insulating materials? | thermoplastic |
What is cotton cloth that has been coated with an insulating varnish known as? | varnished cambric |
How many degrees Celsius is FEP rated at? | 200 degrees |
Which type of fibers have been found to cause severe lung damage and cancer of the gastrointestinal tract? | Asbestos |
How many different types of asbestos wire does the NEC have designators for? | eight |
What serves as a satisfactory insulation for extremely high-voltage cables when it is impregnated with a high grade of mineral oil? | paper |
What type of wire is used on the coils of meters, relays, small transformers, motor windings, and so forth? | magnet wire |
What is the thinnest insulating coating that can be applied to wires? | enamel |
Which type of cable was developed to meet the needs of a noncombustible, high heat-resistant, and water-resistant cable? | Mineral-insulated (MI) |
Up to how many electrical conductors does mineral-insulated (MI) cable have? | 7 |
What are the two categories of materials that make up the protection for a wire or cable? | nonmetallic and metallic |
What is by far the most common type of nonmetallic material used to protect wires and cables? | fibrous braid |
What are the two types of metallic wire protection? | sheath and armor |
Lead-sheathed cable is one of three types currently being used: alloy lead, pure lead, and what else? | reinforced lead |
What is defined as two concentric wires, cylindrical in shape, separated by a dielectric of some type? | coaxial cable |