Firefighting Knowledge Flashcards
7 cards from real NFSI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Firefighting Knowledge flashcards as text
In a building fire, which floor presents the greatest collapse risk for firefighters conducting interior operations?
Answer: The floor immediately above the fire, due to heat weakening the structural assembly
The floor directly above the fire is most vulnerable because heat weakens structural members from below while the floor continues to bear live loads.
What is the function of a pressure relief valve on a fire pump?
Answer: To prevent excessive pressure from damaging hose lines when flow is suddenly reduced
The pressure relief valve opens to bypass water and reduce discharge pressure when a nozzle is shut down suddenly, preventing hose damage or injury.
What hazard is specifically associated with a trench or lean-to roof collapse?
Answer: Secondary collapse from unstable debris on top of the primary collapse
In a lean-to or trench collapse, debris on top of or leaning against the primary collapse is highly unstable and can cause a secondary collapse on rescuers.
Which chemical property determines whether a flammable vapor will rise or sink in air?
Answer: Vapor density
Vapor density compares a gas's weight to air (air = 1); vapors with a vapor density greater than 1 sink and accumulate in low areas, while those less than 1 rise.
What is the correct nozzle technique called when a firefighter sweeps water across the ceiling to cool hot gases before advancing?
Answer: Transitional attack (gas cooling)
Transitional attack, or gas cooling, uses short bursts of a fog or straight stream aimed at the ceiling to cool superheated gases and reduce flashover risk before advancing.
What does IDLH stand for, and what is the significance of the concept in firefighting?
Answer: Immediately Dangerous to Life or Health; defines conditions requiring SCBA use
IDLH (Immediately Dangerous to Life or Health) defines atmospheres where a 30-minute exposure could cause irreversible harm or prevent escape, requiring SCBA.
During a search and rescue operation, what is the primary advantage of a right-hand search pattern?
Answer: It provides a consistent, systematic method that prevents disorientation and ensures full coverage
Maintaining continuous contact with a wall and always turning in the same direction prevents disorientation in zero-visibility conditions and ensures no area is missed.