Fire Safety Fire Behavior and Combustion Science 5

Question 1

What is the name of the phenomenon where fire spreads rapidly along the ceiling in a layer of unburned gases ahead of the flame front?

Accepted Answer

Rollover

Answer

Rollover (also called flameover) occurs when unburned gases at the ceiling ignite and flames roll across the top of the compartment ahead of the main fire.

Question 2

Which factor does NOT directly affect the rate of heat release (RHR) of a burning fuel?

Accepted Answer

Color of the fuel

Answer

Color has no significant effect on rate of heat release; surface area, moisture content, and density all directly influence how quickly a fuel burns.

Question 3

Pyrolysis is best described as:

Accepted Answer

The chemical decomposition of a solid fuel by heat into combustible vapors

Answer

Pyrolysis is a thermochemical decomposition process where solid fuels break down under heat, releasing combustible vapors that can then ignite.

Question 4

In fire behavior, what is the 'upper flammable limit' (UFL)?

Accepted Answer

The concentration of fuel vapor above which the mixture is too rich to ignite

Answer

The UFL (upper flammable limit) is the highest fuel-vapor concentration in air above which there is insufficient oxygen to sustain combustion.

Question 5

A fire investigator notes a low burn pattern and 'V' pattern on a wall. What does a narrow, sharply defined 'V' pattern typically indicate?

Accepted Answer

A fast, intense fire with a well-defined point of origin

Answer

A narrow, sharp 'V' pattern indicates a fast, intense fire with a localized point of origin, while a wide 'V' suggests slower fire development.

Fire Safety Practice Test

Fire Safety Practice Test

Fire Safety Fire Behavior and Combustion Science 5