/ QUESTIONS AND ANSWERS 2025 GRADED A+.
Is NFPA 921 a guide or a standard? - (answers)It is the Guide for Fire and
Explosion Investigations
What are the six steps of the scientific method? - (answers)Recognize the need
Define the problem
Collect the data
Analyze the data
Develop a hypothesis
Test the hypothesis
What step of the scientific method is inductive reasoning? - (answers)Analyze the
data
What step of the scientific method is deductive reasoning? - (answers)Test the
hypothesis
What are the four parts of the fire tetrahedron? - (answers)Fuel (reducing agent)
Heat
Oxidizing agent
Uninhibited chemical chain reaction
,What kind of reaction absorbs energy, an endothermic or an exothermic
reaction? - (answers)Endothermic
What is heat transfer by direct contact called? - (answers)Conduction
What is heat transfer by gas flow / air movement called? - (answers)Convection
What is heat transfer by microwave energy called? - (answers)Radiation
What is a fuel controlled fire? - (answers)A fire that is limited by the amount of
combustibles.
What is a ventilation controlled fire? - (answers)A fire that is limited by the
amount of oxygen.
What are the stages of fire growth? - (answers)Ignition
Growth
Flashover
Fully Developed
Decay
What is a flashover? - (answers)The transition phase from growth to fully
developed, where all surfaces reach ignition temperature almost simultaneously.
,What is ignition of the underside of the hot gas layer called? -
(answers)Flameover or rollover
What factors influence flashover conditions? - (answers)Size of the compartment
Height of ceiling
Ventilation
Amount of fuel
Layout of fuel
Location of fire in the compartment
What are fire patterns? - (answers)The physical manifestation of the affects of fire
on materials.
What are the different types of fire patterns on the walls and ceiling? -
(answers)Plume Generated patterns (often V shaped)
Ventilation generated patterns
Hot gas layer patterns (Line of demarcation)
What is spalling? - (answers)The separation of chunks of concrete with explosive
force caused by the expansion of water (moisture) trapped in the concrete as it
turns to steam
, What is char? - (answers)Pyrolized carbonaceous material
What is oxidation? - (answers)Physical change in appearance of a material
resulting from the combination of oxygen.
What is alloying? - (answers)Mixing two metals heated then cooled to change
their properties. Often melts at a lower temperature.
What is a clean burn? - (answers)When there was enough heat to burn away all
carbon deposits (soot) on a surface leaving a "clean" surface. Occurs on non-
combustible surfaces.
What is soot? - (answers)Elemental carbon produced during incomplete
combustion.
What is calcination? - (answers)When chemically bound water is driven out of
gypsum walls by the heat of the fire.
Does a 25 Watt light bulb expand towards the fire or pull inward away from it? -
(answers)Bulbs 25 watts or less pull away. Bulbs greater than 25 watts will expand
towards the fire.
What causes heat shadowing? - (answers)An object blocking the travel of radiated
heat.