Questions With 100% Answers
What are the conditions needed for a fire to occur? - Answer-fuel (material that acts as
a fuel)
sources of ignition (chemical, biological, or physical)
oxygen
/.What are the components of the fire tetrahedron? - Answer-heat, fuel, oxygen, chain
reaction
/.How do you stop a fire? - Answer-Remove any of the components of the fire
tetrahedron (i.e. remove fuel, oxygen, heat, or interrupt the chemical reaction)
/.Oxygen - Answer--21% ambient air
-robust flaming combustion down to 15-16%
-surface combustion (smoldering) down to about 11%
-loss of consciousness in atmospheres with 12% or less oxygen
/.Heat - Answer-anything that produces the required temperature for ignition
-sun
-open flame
-chemical reaction
-sparks
-friction
/.Fuel - Answer--only vapors burn
-liquids and solids must first be vaporized
-tendency of a substance to vaporize is an indication of its ability to burn
-liquids vaporize more readily than solids
/.Chain reaction - Answer--you can have oxygen, heat, and fuel in the same place and
still not have a fire
-fuel and oxygen relationship must be balanced (i.e. in the flammable range)
-heat must be sufficient to bring fuel to its ignition
/.What is a flash point (of a liquid)? - Answer--the lower temp that a liquid can give off
sufficient gas to form a flammable gas mixture near the surface of a liquid
-lowest temp at which we can have fire
-fire flashes across surface given sufficient oxygen and an external source of ignition
/.What is a Fire point? - Answer--just above the flash point, liquid gives off flammable
vapors rapidly enough to support continuous combustion
, /.What is ignition temperature? - Answer--substance starts to burn
-heat from external heat source
-auto-ignitio, no external source of ignition needed
/.What is auto ignition? - Answer-vapor generated ignites without any outside ignition
source
/.What is vaporization? - Answer-rate increases with temperature
/.What is spontaneous combustion? - Answer-heat is generated by a chemical action
within a substance and this continues until you have ignition (usually begins with
oxidation and combines oxygen and gives off energy in the form of heat)
/.What is lower flammable limit? - Answer-the least concentration of flammable vapors
in air that will burn
/.What is upper flammable limit - Answer-the greatest concentration of flammable
vapors in the air that will burn
/.What are the results of combustion? - Answer-smoke, flame, heat, and gases
/._____________ is the result of incomplete combustion - Answer-smoke
/.White or light grey indicates ____________ burning - Answer-free
/.Black or dark grey indicates a ______ fire or a _________ of oxygen - Answer-hot,
lack
/.How is flame produced? - Answer-result of conversation of the fuel to a state of blazing
combustion
/.How is heat generated? - Answer-rapid oxidation of the material
/.How are gases produced? - Answer-result of combustion, may or may not be toxic
/.What are the characteristics of the incipient stage of a fire? - Answer--cool
-good combustion
-little smoke
-good visability
-easy to breath
-radiative feedback
/.What are the characteristics of the freeborn stage? - Answer--hot
-poor combustion
-dense smoke