Fire Behavior & Combustion Principles Flashcards
7 cards from real CFM practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Fire Behavior & Combustion Principles flashcards as text
The fire tetrahedron model adds which fourth element to the traditional fire triangle?
Answer: Uninhibited chemical chain reaction
The fire tetrahedron adds the uninhibited chemical chain reaction to the fire triangle's three elements (heat, fuel, oxygen), representing the self-sustaining nature of combustion.
'Rollover' or 'flameover' during a structure fire refers to:
Answer: Flames rolling across the ceiling as unburned gases ignite
Rollover (flameover) occurs when unburned combustible gases accumulate at ceiling level and ignite, causing flames to roll across the ceiling — a warning sign that flashover is imminent.
The spread of fire through airborne burning embers carried by wind or convection currents is called:
Answer: Spotting
Spotting occurs when burning embers (firebrands) are carried by wind and convection to ignite new fires at a distance from the primary fire, common in wildland and wildland-urban interface fires.
In thermal layering within a burning structure, where does the highest temperature zone typically exist?
Answer: At ceiling level where hot combustion gases accumulate
In thermal layering, the hottest combustion gases rise and accumulate at ceiling level, creating distinct temperature zones with the highest temperatures near the ceiling.
The auto-ignition temperature (AIT) of a material is defined as the temperature at which it:
Answer: Ignites spontaneously in air without any external ignition source
Auto-ignition temperature (AIT) is the minimum temperature at which a material will spontaneously ignite in air without any external spark, flame, or ignition source.
Which factor most significantly affects the rate of fire spread within a structure?
Answer: Fuel load, arrangement, and combustibility of materials present
The rate of fire spread is most significantly affected by the fuel load — including the quantity, arrangement, and combustibility of materials available to sustain and spread the fire.
How does a material's surface area-to-mass ratio affect its ignitability?
Answer: A higher surface area-to-mass ratio makes a material more easily ignitable
Materials with a higher surface area-to-mass ratio (such as fine wood shavings versus a solid log) expose more surface to heat and oxygen, making them significantly more easily ignitable.