F80 Fire Behavior and Combustion Principles 1 — Questions and Answers
Question 1: What are the three elements of the fire triangle?
- Fuel, oxygen, and heat (Correct answer)
- Fuel, water, and heat
- Oxygen, nitrogen, and heat
- Fuel, carbon dioxide, and heat
Correct answer: Fuel, oxygen, and heat
The fire triangle consists of fuel, oxygen, and heat — removing any one element will extinguish the fire.
Question 2: What is flashover in fire behavior?
- When a fire is fully extinguished
- The rapid transition to full room involvement when all combustible surfaces ignite simultaneously (Correct answer)
- When sprinkler heads activate automatically
- The initial ignition of a fire at its point of origin
Correct answer: The rapid transition to full room involvement when all combustible surfaces ignite simultaneously
Flashover is the rapid transition where radiant heat causes all combustible surfaces in a compartment to ignite simultaneously.
Question 3: Which class of fire involves flammable and combustible liquids?
- Class A
- Class B (Correct answer)
- Class C
- Class D
Correct answer: Class B
Class B fires involve flammable and combustible liquids such as gasoline, oil, and grease.
Question 4: What is the primary product of complete combustion of hydrocarbons?
- Carbon monoxide
- Carbon dioxide and water vapor (Correct answer)
- Hydrogen cyanide
- Black soot particles
Correct answer: Carbon dioxide and water vapor
Complete combustion of hydrocarbons produces carbon dioxide (CO2) and water vapor as the fully oxidized end products.
Question 5: Which gas is most responsible for fire-related fatalities?
- Carbon dioxide
- Oxygen depletion alone
- Carbon monoxide (Correct answer)
- Nitrogen dioxide
Correct answer: Carbon monoxide
Carbon monoxide is the leading cause of fire deaths because it is colorless, odorless, and binds to hemoglobin far more readily than oxygen.
Question 6: What is backdraft?
- A fire that has been suppressed by CO2
- A rapid combustion explosion caused by sudden oxygen introduction to a smoldering, oxygen-depleted fire (Correct answer)
- The decay phase of a fire's development cycle
- Fire spreading in the direction opposite to wind flow
Correct answer: A rapid combustion explosion caused by sudden oxygen introduction to a smoldering, oxygen-depleted fire
Backdraft occurs when oxygen suddenly enters an oxygen-depleted, smoldering enclosure, causing explosive ignition of accumulated fuel gases.
F80 Fire Behavior and Combustion Principles 1
What are the three elements of the fire triangle?