CAT Material Selection & Properties 2

Question 1

Which insulation material is most commonly used on wiring inside alarm control panels due to its flame-retardant properties?

Accepted Answer

PVC (polyvinyl chloride)

Answer

PVC insulation is standard in alarm control panels because it is inherently flame-retardant and resists moisture.

Question 2

When selecting wire for a buried outdoor loop detector circuit, which material property is most critical?

Accepted Answer

Direct burial-rated jacket with moisture resistance

Answer

Buried wiring must have a direct burial-rated jacket that resists moisture, soil chemicals, and physical abrasion.

Question 3

A technician needs conduit for an installation passing through a corrosive chemical storage area. Which material is the best choice?

Accepted Answer

PVC Schedule 40 conduit

Answer

PVC conduit is chemically inert and will not corrode in environments with harsh chemicals.

Question 4

What is the primary reason THWN wire is preferred over THW wire for wet-location conduit runs?

Accepted Answer

THWN has a nylon outer jacket that resists moisture and pulling abrasion

Answer

The 'N' in THWN stands for nylon, which adds a tough outer jacket suitable for wet locations and easier conduit pulling.

Question 5

Which conductor material has the highest electrical conductivity per unit cross-section?

Accepted Answer

Copper

Answer

Copper has higher electrical conductivity than aluminum, steel, or coated variants, making it the preferred conductor in alarm wiring.

(CAT) Certified Alarm Technician Level I Practice Test