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
What does the term 'fuel load' refer to in fire science?
Answer: The weight of combustible materials per unit area in a given space
Fuel load refers to the total quantity of combustible materials per unit area in a given space, typically expressed in BTUs or pounds per square foot.
Which mechanism of fire spread involves the movement of hot gases and smoke carrying heat to unburned areas?
Answer: Convection
Convection spreads fire through the movement of hot gases and smoke, which rise and carry heat energy to adjacent unburned areas above and around the fire.
Backdraft occurs when a fire in an oxygen-limited environment suddenly:
Answer: Receives a sudden influx of oxygen
Backdraft occurs when a smoldering, oxygen-starved fire receives a sudden fresh supply of oxygen — such as when a door is opened — causing rapid, explosive combustion.
The rate of heat release (HRR) from a burning material is most commonly expressed in:
Answer: BTUs per hour or kilowatts (kW)
Heat release rate (HRR) measures the power output of a fire and is expressed in BTUs per hour or kilowatts (kW), indicating how quickly energy is being released.
Smoldering combustion is best characterized by which of the following?
Answer: Burning at the fuel surface without producing a visible flame
Smoldering (glowing) combustion occurs when a material burns without producing a visible flame, typically at the fuel surface, and can persist for extended periods.
What is pyrolysis in the context of fire behavior?
Answer: The thermal decomposition of materials producing combustible gases
Pyrolysis is the thermal decomposition of solid or liquid materials when exposed to heat, producing combustible gases that can then mix with air and ignite.
The upper explosive limit (UEL) of a flammable gas or vapor refers to:
Answer: The maximum concentration above which the mixture is too fuel-rich to ignite
The upper explosive limit (UEL) is the maximum concentration of flammable vapor in air above which the mixture contains too much fuel and insufficient oxygen to sustain combustion.