Is 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
... [Show More] 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 Flame over 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 effects 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 separate 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
What is the difference between and arc and a spark? CORRECT ANSWER Sparks are thrown metal particles
Arcs are brief discharges of electricity
What is arc tracking? CORRECT ANSWER Arc following salts, dusts, or liquids along a path.
What is arc mapping? CORRECT ANSWER Mapping out of electrical damage in a circuit. [Show Less]