CFM Fire Behavior & Combustion Principles 3

Question 1

The fire tetrahedron model adds which fourth element to the traditional fire triangle?

Accepted Answer

Uninhibited chemical chain reaction

Answer

Carbon dioxide production

Answer

Thermal radiation energy

Answer

Combustion byproducts

Question 2

'Rollover' or 'flameover' during a structure fire refers to:

Accepted Answer

Flames rolling across the ceiling as unburned gases ignite

Answer

The rapid simultaneous ignition of all materials in a room

Answer

An explosive ignition caused by a sudden introduction of oxygen

Answer

The progressive collapse of a weakened burning roof structure

Question 3

The spread of fire through airborne burning embers carried by wind or convection currents is called:

Accepted Answer

Spotting

Answer

Conductive spread

Answer

Convective lift

Answer

Flame impingement

Question 4

In thermal layering within a burning structure, where does the highest temperature zone typically exist?

Accepted Answer

At ceiling level where hot combustion gases accumulate

Answer

At floor level near the base of the fire

Answer

In the middle of the room at average breathing height

Answer

Near windows and exterior walls where air enters

Question 5

The auto-ignition temperature (AIT) of a material is defined as the temperature at which it:

Accepted Answer

Ignites spontaneously in air without any external ignition source

Answer

Begins to produce flammable vapors detectable by sensors

Answer

Reaches its melting point and transitions to a liquid fuel state

Answer

Produces its maximum rate of heat release during combustion

Question 6

Which factor most significantly affects the rate of fire spread within a structure?

Accepted Answer

Fuel load, arrangement, and combustibility of materials present

Answer

The color and reflectivity of interior wall finishes

Answer

The number of occupants and their evacuation routes

Answer

The height of the building's ceilings and floor-to-floor dimensions

Question 7

How does a material's surface area-to-mass ratio affect its ignitability?

Accepted Answer

A higher surface area-to-mass ratio makes a material more easily ignitable

Answer

Materials with lower surface area-to-mass ratios ignite more easily and quickly

Answer

Surface area has no measurable effect on the ignitability of combustible materials

Answer

Only the total mass of a material determines how quickly it will ignite