Types of Conductors Review

Question 1

The resistance of a wire depends on four main factors:

Answer 1

-Natural resistance (Resistivity)
-Length of the wire
-Temperature
-Cross-sectional area of the wire

Question 2

Resistivity is often expressed in what unit?

Answer 2

ohms/mil-foot

Question 3

AWG is also called ______and has been used since the mid-1800s to indicate a wire’s current carrying ratings.

Answer 3

Brown & Sharpe Wire Gauge

Question 4

The term “_____” reference wires that are up to 1 AWG.

Answer 4

gauge

Question 5

The term “____” refers to wires that are 1/0 AWG or larger. Expressed as 0, 00, 000 & 0000

Answer 5

aught

Question 6

Four Types of Conductor Applications are……

Answer 6

1. Power
2. Fixture
3. Communication
4. Control

Question 7

POWER: used to distribute the electrical energy within a building. What are the two types “power” conductors we use (CEC)?

Answer 7

1. Service wiring
2. branch wiring

Question 8

Service wiring: usually large “_____” cables

Answer 8

Feeder

Question 9

Canadian Electrical Code state that the minimum conductor size permitted in house is #___AWG.

Answer 9

14

Question 9

If you are wiring in non-combustible building, which wire/cable should you use?

Answer 9

BX cable or conduit

Question 10

If you are wiring in combustible building, which wire/cable should you use?

Answer 10

Loomex wire

Question 10

Under Canadian Electrical code, how many volts is considered “extra low voltage.”

Answer 10

30 volts or less

Question 11

Some use “___” conductors to minimize the electromagnetic and capacitive interference.

Answer 11

Shielded

Question 12

What is a shield?

Answer 12

A metallic covering which is wrapped around the conductors - this acts as a Faraday cage.

Question 13

What is a NMSC?

Answer 13

Non-Metallic Sheathed Cable.

Question 14

Which location should you wire NMD 90?

Answer 14

Dry location

Question 15

What is the Mineral Insulated Cable trade name?

Answer 15

Pyrotenax

Question 16

4 main facts of Mineral Insulated Cable

Answer 16

1. also called MI cable
2. Has a magnesium oxide inside and a smooth copper sheath
3. Fire resistant
4. LWMI- light weight mineral insulated cable good up to 600Volts

Question 17

What is the purpose of sheath around the conductor?

Answer 17

To protect the conductor from penetration or damages

Question 18

Which cable should you use in residential buildings?

Answer 18

Loomex or Romex

Question 19

Which cable should you use in commercial buildings

Answer 19

BX cable or conduit

Question 20

What is another term used for FCC?

Answer 20

Under carpet cable

Question 21

what does FCC stand for?

Answer 21

Flat Copper Conductor

Question 22

Wire is insulated by dipping it in a varnish or enamel

Answer 22

Magnet wire

Question 23

The ability of a material to be rolled or hammered into thin sheets.

Answer 23

Malleability

Question 24

A mineral used for insulation and is capable of operation a very high temperature

Answer 24

Magnesium Oxide

Question 25

An insulation use where flexibility and abrasion resistance are of prime importance.

Answer 25

Rubber

Question 26

A type of insulation material that softens when heated, and conversely hardens when cooled.

Answer 26

Thermoplastic

Question 27

What is the opposite of resistance?

Answer 27

Conductance

Question 28

what is resistivity constant for copper?

Answer 28

10.4 ohm per mil-foot

Question 29

A type of insulation made by impregnating cloth with varnish.

Answer 29

Varnish Cambric

Question 30

A type of insulation that when held in a flame melts, drips and burns, but when the flame is removed, instantly self-extinguishes.

Answer 30

Flame Seal

Question 31

What is a trade name for Polyvinylchloride?

Answer 31

PVC

Question 32

The ability of a material to be drawn into a wire.

Answer 32

Ductility

Question 33

What is the resistivity of aluminum?

Answer 33

17ohm per mil-foot

Question 34

A phenomenon which may result in the connection points in a circuit losing their grip.

Answer 34

Cold Flow

Question 35

What is a main advantage of using MI cable?

Answer 35

High temperatures applications

Question 36

What is an enamel?

Question 37

A special type of wire used within electrical equipment such as lighting fixtures.

Answer 37

Fixture Wire

Question 38

Defined Ampacity

Answer 38

Ampacity is defined as the current in amperes a conductor can carry continuously under the condition without exceeding it temperature rating.

Question 39

The ampacity of_____-temperature conductor is greater than the ampacity of_____-temperature.

Answer 39

High, low For Example, #8 90C copper has an ampacity of 55A #8 60C copper has an ampacity of 40A