Questions With 100%Verified
AnswersA+GRADED
NFPA 921 a guide or a standard? - correct answer...✔✔It is the Guide for Fire and
Explosion Investigations
What are the six steps of the scientific method? - correct answer...✔✔Recognize the
need
Define the problem
Collect the data
Analyze the data
Develop a hypothesis
Test the hypothesis
What step of the scientific method is inductive reasoning? - correct answer...✔✔
Analyze the data
What step of the scientific method is deductive reasoning? - correct answer...✔✔Test
the hypothesis
What are the four parts of the fire tetrahedron? - correct answer...✔✔Fuel (reducing
agent)
Heat
Oxidizing agent
Uninhibited chemical chain reaction
What kind of reaction absorbs energy, an endothermic or an exothermic reaction? -
correct answer...✔✔Endothermic
What is heat transfer by direct contact called? - correct answer...✔✔Conduction
What is heat transfer by gas flow / air movement called? - correct answer...✔✔
Convection
What is heat transfer by microwave energy called? - correct answer...✔✔Radiation
What is a fuel controlled fire? - correct answer...✔✔A fire that is limited by the amount
of combustibles.
,What is a ventilation controlled fire? - correct answer...✔✔A fire that is limited by the
amount of oxygen.
What are the stages of fire growth? - correct answer...✔✔Ignition
Growth
Flashover
Fully Developed
Decay
What is a flashover? - correct answer...✔✔The transition phase from growth to fully
developed, where all surfaces reach ignition temperature almost simultaneously.
What is ignition of the underside of the hot gas layer called? - correct answer...✔✔
Flameover or rollover
What factors influence flashover conditions? - correct answer...✔✔Size of the
compartment
Height of ceiling
Ventilation
Amount of fuel
Layout of fuel
Location of fire in the compartment
What are fire patterns? - correct answer...✔✔The physical manifestation of the affects
of fire on materials.
What are the different types of fire patterns on the walls and ceiling? - correct answer...
✔✔Plume Generated patterns (often V shaped)
Ventilation generated patterns
Hot gas layer patterns (Line of demarcation)
What is spalling? - correct answer...✔✔The separation of chunks of concrete with
explosive force caused by the expansion of water (moisture) trapped in the concrete as
it turns to steam
What is char? - correct answer...✔✔Pyrolized carbonaceous material
What is oxidation? - correct answer...✔✔Physical change in appearance of a material
resulting from the combination of oxygen.
What is alloying? - correct answer...✔✔Mixing two metals heated then cooled to
change their properties. Often melts at a lower temperature.
,What is a clean burn? - correct answer...✔✔When there was enough heat to burn
away all carbon deposits (soot) on a surface leaving a "clean" surface. Occurs on non-
combustible surfaces.
What is soot? - correct answer...✔✔Elemental carbon produced during incomplete
combustion.
What is calcination? - correct answer...✔✔When chemically bound water is driven out
of gypsum walls by the heat of the fire.
Does a 25 Watt light bulb expand towards the fire or pull inward away from it? - correct
answer...✔✔Bulbs 25 watts or less pull away. Bulbs greater than 25 watts will expand
towards the fire.
What causes heat shadowing? - correct answer...✔✔An object blocking the travel of
radiated heat.
What is a dead load? - correct answer...✔✔The weight of things attached to the
building, like flooring, cloumns, and roof coverings.
What is a live load? - correct answer...✔✔A load that can move, like people, furniture,
wind, water, and snow.
What is compartmentation? - correct answer...✔✔Design features of a building that
limit fire growth to the room of origin.
What are the five building construction types? - correct answer...✔✔Type I - Fire
resistant
Type II - Non combustible
Type III - Ordinary
Type IV - Heavy timber
Type V - Wood frame
What is ordinary construction? - correct answer...✔✔Exterior walls are masonry and
frame is wood.
What is wood frame construction? - correct answer...✔✔Lightweight wood
construction, used in apartments, houses.
What is platform frame construction? - correct answer...✔✔Each floor is a seperate
platform.
What is balloon frame construction? - correct answer...✔✔The wall studs extend from
the foundation to the roof.
, What is Ohm's Law? - correct answer...✔✔V=IR
(E = I x R)
What is voltage? - correct answer...✔✔Pressure
What is current? - correct answer...✔✔Flow
What is resistance? - correct answer...✔✔Friction, opposition to the flow
What is an overload? - correct answer...✔✔Power needs exceed the circuit's capacity.
Alternating Current VS Direct Current - correct answer...✔✔Alternating current - the
electrons flow out from the source and then back to it, alternating directions.
Direct current - electrons flow one way.
Single Phase service - correct answer...✔✔Residential. Three conductors: Two
insulated conductors at 120 V each, and a bare ground wire.
Three phase system - correct answer...✔✔Commercial. Four conductors: Three
insulated conductors (480, 240, or 208 V), and a bare ground wire.
What is the difference between grounding and bonding? - correct answer...✔✔
Grounding connects the system to the earth (ground). Bonding connects to systems
together so the charge stays the same between them.
What is overcurrent protection? - correct answer...✔✔A device that protects the system
from excess current. Includes:
Circuit breakers
Plug fuses
Type S fuses
Time delay fuses
Cartridge fuses
What are the colors of residential wires? - correct answer...✔✔Hot - black or red
Neutral - gray or white
Ground - bare or green
What are some methods of electrical heat production? - correct answer...✔✔
Resistance heating
Short circuit
Ground fault
Parting Arc
Excessive current