CFI CFI Fire Dynamics & Behavior

Question 1

What term describes the minimum temperature at which a liquid fuel produces enough vapor to ignite momentarily when an ignition source is applied?

Accepted Answer

Flash point

Answer

The flash point is the lowest temperature at which a liquid produces sufficient vapor to form an ignitable mixture near its surface.

Question 2

Which heat transfer mechanism involves the movement of hot combustion gases rising from a fire and spreading heat throughout a compartment?

Accepted Answer

Convection

Answer

Convection transfers heat through the physical movement of hot gas molecules, causing them to rise and circulate within a compartment.

Question 3

The transition from a localized fire to full room involvement where all combustible surfaces ignite simultaneously is called:

Accepted Answer

Flashover

Answer

Flashover occurs when radiant heat from the hot gas layer raises all exposed combustible surfaces to their ignition temperature simultaneously.

Question 4

What condition occurs when fresh air suddenly enters a vitiated (oxygen-depleted) compartment containing hot unburned gases, causing a rapid deflagration?

Accepted Answer

Backdraft

Answer

Backdraft is a smoke explosion caused by the sudden introduction of oxygen into a superheated, oxygen-depleted compartment full of unburned fuel gases.

Question 5

Which of the following best describes the 'heat release rate' (HRR) in fire dynamics?

Accepted Answer

The rate at which a fire produces thermal energy measured in kilowatts

Answer

Heat release rate (HRR), measured in kilowatts or megawatts, is the single most important variable in fire dynamics as it determines fire growth and severity.

(CFI) Certified Fire Investigator Practice Test

(CFI) Certified Fire Investigator Practice Test

CFI CFI Fire Dynamics & Behavior