Ch 1 - P 1 - Metallic Media And Electrical Conductors

Question 1

What is an electrical conductor?

Answer 1

Any material that can carry an electric charge from one point to another

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Question 2

Name the 4 most common electrical conductors for ICT wires and Cables.

Answer 2

1 - Copper
2 - Copper covered steel
3 - High-strength copper alloys
4 - Aluminum

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Question 3

Silver and Gold are good conductors, but they are not generally used for ICT wires and cables. Why?

Answer 3

Because of their high cost

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Question 4

Which conductor sets the standard for comparing the conductivity of other metals?

Answer 4

Copper

TDMM: Page 1-3, Table 1.1

Question 5

What type of copper is used to set the reference value?

Answer 5

Annealed copper

TDMM: Page 1-3, Table 1.1

Question 6

What type of conductor is typically used for aerial, self-supporting drop wire?

Answer 6

Copper Covered

TDMM: Page 1-3, Table 1.1

Question 7

How does the alloying of pure copper affect its conductivity?

Answer 7

The alloying of pure copper always has an adverse effect on its conductivity.

TDMM: Page 1-3, Table 1.1

Question 8

How does the conductivity of aluminum compare the conductivity of copper?

Answer 8

It has about 60 percent conductivity compared to copper.

TDMM: Page 1-3, Table 1.1

Question 9

Where are aluminum conductors commonly used?

Answer 9

In electrical utility distribution lines

TDMM: Page 1-3 Table 1.1

Question 10

Where are aluminum conductors commonly used?

Answer 10

In electrical utility distribution lines

TDMM: Page 1-3, Table 1.1

Question 11

Why is type of solid conductor has the poorest corrosion resistance?

Answer 11

High-strength alloy

TDMM: Page 1-4, Table 1.2

Question 12

What type of solid conductor has the poorest oxidation resistance?

Answer 12

Aluminum

TDMM: Page 1-4, Table 1.2

Question 13

Which type of solid conductor has the best tensile strength?

Answer 13

High-strength alloy

TDMM: Page 1-4, Table 1.2

Question 14

Which type of solid conductor has the best ductility?

Answer 14

High Strength alloy

TDMM: Page 1-4, Table 1.2

Question 15

What is the conductivity for a high-strength alloy conductor?

Answer 15

85% of typical

TDMM: Page 1-4, Table 1.2

Question 16

How are stranded conductors created?

Answer 16

By bundling together a number of small-gauge solid conductors to create a single, larger conductor

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Question 17

Name 4 advantages of of solid conductors:

Answer 17

1. Less Costly
2. Less complex termination systems
3. Better transmission performance at high frequencies
4. Less Resistance

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Question 18

Name 3 advantages of stranded conductors:

Answer 18

1. More Flexible
2. Longer flex life
3. Less susceptible to damage during crimp termination processes

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Question 19

Which is a composite conductor?

Answer 19

A conductor constructed from non traditional materials (e.g., metallic resins or graphite)

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Question 20

Name 5 advantages of composite conductors:

Answer 20

1. Highly flexible
2. Lightweight
3. Inexpensive and easy to produce
4. Easily embedded into other materials
5. Low coefficient of expansion

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Question 21

Name 4 disadvantages of composite conductors:

Answer 21

1. Poor analog transmission characteristics including high attenuation, especially above 4000 Hz
2. Poor digital transmission characteristics
3. Easily damaged unless encased in a rigid material
4. Inconsistent quality

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Question 22

Are Cables with composite conductors recommended for use with modern telecommunications networks?

Answer 22

No. Cables with composite conductors are not recommended for use with modern telecommunications networks. If equipment is shipped with this type of cable, discard and replace it with the proper structured cabling patch cord for the project.

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Question 23

Why is the AWG system important?

Answer 23

Because it provides a standard reference for comparing various conductor materials.

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Question 24

What is the purpose of insulation on a cable?

Answer 24

To isolate the flow of current by preventing direct contact between conductors and a conductor and its environment.

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Question 25

How do dielectrics reduce EM coupling between conductors?

Answer 25

By increasing conductor separation

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Question 26

What is a dielectric constant?

Answer 26

The ratio of the capacitance of the insulated conductor to the same capacitance of the same conductor uninsulated in the air.

TDMM: Page 1-8, Table 1.4

Question 27

What does dielectric strength measure?

Answer 27

The maximum voltage that an insulation can withstand without breakdown.

TDMM: Pate 1-8, Table 1.4

Question 28

What is dissipation factor?

Answer 28

The relative power loss in the insulation due to molecular excitement and subsequent kinetic and thermal energy losses

TDMM: Page 1-8, Table 1.4

Question 29

What is insulation resistance?

Answer 29

The insulation’s ability to resist the flow of current through it.

TDMM: Page 1-8, Table 1.4

Question 30

How is insulation resistance typically expressed?

Answer 30

In megaohmkm or megaohm1000 ft

Question 31

How does cable length affect cable resistance?

Answer 31

As the cable length increases, the insulation resistance becomes smaller.
TDMM: page 1-8, Table 1.4