Question

for a quick knockdown on class c fires, \\(\text{co}_2\\) should be applied:

at close range.
from at least 12 feet away.
facing the wind.
in conjunction with a class a extinguisher.

question 58

whether de-energized or not, fire involving electrical equipment can be fought effectively with extinguishers containing a halogenated agent, \\(\text{co}_2\\), dry chemical, or:

afff.
water.
water-mist.
ffp.

Explanation:

Analyze the first question on Class C fires and CO₂ application

The first question asks: "For a quick knockdown on Class C fires, \(CO_2\) should be applied:"

• Class C fires involve energized electrical equipment.
• Carbon Dioxide Extinguishers have a relatively short discharge range (typically 3 to 8 feet) because the gas disperses rapidly in the air.
• To achieve a quick knockdown, the agent must be applied at close range to displace oxygen and cool the fuel before the gas dissipates. Applying it from 12 feet away is ineffective due to range limitations, and facing the wind would blow the gas away from the fire.
• Therefore, the correct option is "at close range."

Analyze the second question on electrical equipment fires

The second question (labeled Question 58) asks: "Whether de-energized or not, fire involving electrical equipment can be fought effectively with extinguishers containing a halogenated agent, \(CO_2\), dry chemical, or:"

• Fires involving electrical equipment are classified as Class C fires.
• The extinguishing agent must be non-conductive to ensure operator safety, especially if the equipment is not de-energized.
• AFFF (Aqueous Film-Forming Foam) and standard water are highly conductive and present severe shock hazards. FFP is not a standard extinguishing agent.
• Water-mist extinguishers use deionized water and a specialized nozzle that creates a fine mist, making the discharge non-conductive and safe for use on energized electrical equipment (Class C hazards).
• Therefore, the correct option is "water-mist."

Answer:

Question 1

• (A) at close range. (Correct answer)
• (B) from at least 12 feet away.
• (C) facing the wind.
• (D) in conjunction with a Class A extinguisher.

Question 2

• (A) AFFF.
• (B) water.
• (C) water-mist. (Correct answer)
• (D) FFP.