A1 LT13

Question 1

What happens if too much heat is present in a circuit application?

Answer 1

Insulation may melt or burn

Question 2

What is cambric known for?

Answer 2

Hygroscopic and absorbs moisture.

Question 3

Why should insulation be appropriate for its location?

Answer 3

Moisture and toxic elements can cause insulation deterioration

Question 4

What are the types of rubber commonly used as insulation?

Answer 4

Natural rubber and silicone-based rubber.

Question 5

What is a material used in a strong, moisture-proof sheath for carrying heavier current?

Answer 5

Copper

Question 6

What are rubber compounds used for?

Answer 6

Flexibility and abrasion resistance

Question 7

Why does most electrical wiring circuits look complicated?

Answer 7

Multiple wires at any one point

Question 8

What characteristics must be kept in mind when using cables?

Answer 8

Cold flow, warmer plastic flows faster

Question 9

How are conductors marked for identification?

Answer 9

Coloured insulation or labelled marker

Question 10

How does high temperatures affect insulation life expectancy?

Answer 10

Reduced by one-half for every 10C beyond normal rating

Question 11

How can polyvinylchloride (PVC) be identified?

Answer 11

Flame test - melts, drips, burns, self-extinguishes

Question 12

What does a green wire indicate?

Answer 12

Bonding conductor

Question 13

What is the operation voltage limit for PVC insulation according to the Code?

Answer 13

600 V AC

Question 14

What do red, black, or blue wires typically indicate?

Answer 14

Live or hot

Question 15

What is the maximum conductor temperature allowed for PVC insulation?

Answer 15

60C

Question 16

What is the surface marking for cross-linked polyethylene as required by the Code?

Answer 16

XLPE or X LINK

Question 17

What happens to thermosetting materials when they are heated?

Answer 17

They harden

Question 18

What properties are improved in thermosetting materials when they harden?

Answer 18

Electrical, thermal, mechanical

Question 19

What is mica used for?

Answer 19

High temperature applications like toasters and irons.

Question 20

Which colours are reserved for specific applications according to the Canadian Electrical Code?

Answer 20

White or natural grey

Question 21

What are some applications of enamel as an insulating material?

Answer 21

Meter coils, transformers, motor windings

Question 22

What are thermoplastic materials’ properties when heated?

Answer 22

Soften

Question 23

In what cases does a white wire not indicate a neutral conductor?

Answer 23

Switch loops

Question 24

What happens to thermoplastic materials when they cool?

Answer 24

Harden

Question 25

What are some trade names for PVC?

Answer 25

Flameseal, Flamenol

Question 26

Which PVC insulation type is suitable for direct burial in the ground?

Answer 26

TWU

Question 27

How is cross-linked polyethylene affected by cold once installed?

Answer 27

Not affected

Question 28

What does a white wire indicate in a circuit?

Answer 28

Neutral conductor

Question 29

What happens if you stretch cambric insulation too tightly?

Answer 29

Varnish film may be broken or weakened.