Chapter 1: Fire protective system
________ fires involve energized electrical equipment, so the choice of extinguishing agents must be appropriate to minimize potential danger to those involved in fighting the fire
Class C
Which class of fire involves combustible metals & dusts that are generally extinguished using a dry powder extinguishing agent?
Class D
Which type of fire involves cooking appliances using combustible vegetable or animal fat & oils ?
Class K
______ is a chemical reaction in which a combustible material & an oxidizing agent produce heat or energy, & other products that promote a self-sustaining process
Combistion
Of the different methods of heat transfer, which is the transfer of heat from one body of material to another by direct contact ?
Conduction
Which of the following forms of heat transfer occurs from one body to another through a medium such as a liquid or gas ?
Convection
This fire is most recognizable, can be seen by lighting a match, & requires the presence of a combustible gas
Diffusion flame
The effect of convection is directly influenced by the size & shape of the:
Fire compartment
In this transition stage, the temperature in a room or space reaches a point at which all of the surfaces of the room or space simultaneously ignite, immediately leading to full room involvement
Flash over
Which commonly used suppression agent can cover leaking fuel so that oxygen cannot reach the fuel?
Foam
At which stage will a fire survive by consuming the air and materials necessary to generate the flammable gas & sustain combustion?
Free burning stage
What type of material is generally the best for heat transfer through, conduction, because it absorbs & transmits heat rapidly & evenly ?
Heavy, dense material
Which stage of fire occurs when the heat source, fuel, & oxygen come together to generate more heat than is dissipated, thus promoting the inhibited chain reaction ?
Incipient stage
Which type of material produces twice the amount of heat per pound than common combustibles ?
Plastic
This type of fire requires an appropriate amount of gas fuel & air mix before ignition or combustion occurs
Premixed flame
______ is the form of heat transfer that occurs through electromagnetic energy. One ex. of this process is the sun heating the earth through millions of miles of space.
Radiation
Firefighters sometimes intentionally set controlled fires to remove fuel ahead of a hostile, uncontrolled fire. This is known as:
Removing or interrupting the fuel supply
What factor has a significant impact on fire growth, in addition to the shape of surrounding walls, ceilings, & roofs
Size of a structure
Which type of fire usually seen w charcoal briquettes, has no flame, but still generates significant heat
Smoldering
When a fire begins to subside to the point at which the available fuel is exhausted or the oxygen level drops below 16 percent, it has reached which stage of fire ?
Smoldering/decay stage
Class B fires involving flammable & combustible liquids are typically extinguished through which action ?
Smothering
This type of fire starts w/o a know external heat source being applied to the combustible material ?
Spontaneous combustion
Which of the following is a geometric depiction, developed through on going research, showing how fire is sustained by a chain reaction ?
The fire tetrahedron
What has served as a teaching tool to geometrically depict the relationship between fuel, air, & heat ?
The fire triangle
In the 1900's which of the following organizations developed a method of classifying or categorizing fires based on the extinguishing agent that was appropriate for the type of fire ?
Underwriters Labroratories
Which of the following g extinguishing agents is NOT used to break the chain reaction through displacing the available oxygen ?
Water
_______ is the most effective suppression agent for Class A fires because it has the ability to absorb the heat and reduce the temp. blow the material's ignition temp.
Water
The design of water based fire extinguishing systems is based on the premise that one gallon of water, when properly applied, can absorb how many British thermal units ?
8000