更多"Halon extinguishers used on a class"的相关试题:
[单项选择]Portable CO2 fire extinguishers should NOT be used to inert a space containing flammable liquids due to the danger of（）.
A. the CO2 being inhaled by personnel
B. reflash of burning liquids
C. vapor condensation on the extinguisher
D. the discharge causing a static spark
[单项选择]Halon from extinguishers used on a class B fire，should be directed（）.
A. at the top of the flames
B. at the base of the fire near the edge
C. in short quick bursts
D. toward the upwind side of the fire
[单项选择]Portable carbon dioxide fire extinguishers should be sent ashore to be recharged （）.
A. when the remaining charge volume is less than 90 percent of the required VOLUME
B. at each inspection for certification
C. at each annual inspection
D. when the weight loss exceeds 10% of weight of charge
[单项选择]Which is a disadvantage of Halon as a fire extinguishing medium?（）
A. Conducts electricity
B. Difficult to store
C. Large volume necessary to be effective
D. Ineffective in powdered metal fires
[单项选择]Halon extinguishes a fire by（）.
A. breaking the chain reaction
B. smothering the fire
C. cooling the fire
D. coating the fule with a nonflammable surface
[单项选择]Halon extinguishes fire primarily by（）.
A. cooling
B. smothering
C. shielding of radiant heat
D. breaking the chain reaction
[单项选择]Any extinguishing agent used on a Class C fire must have which important property?（）
A. Cooling ability
B. Leaves no residue
C. Penetrating power
D. Nonconductivity
[单项选择]Halon fire extinguishers are NOT effective when used on which types of fires?（）
A. Fires in electrical equipment
B. Flammable oils and greases
C. Class A fires in ordinary combustibles
D. Materials containing their own oxygen
[单项选择]On a class B fire，which portable fire extinguisher would be the LEAST desirable?（）
A. Carbon dioxide
B. Water (stored pressure)
C. Dry chemical
D. Foam
[单项选择]Dry chemical extinguishers extinguish class B fires to the greatest extent by（）.
A. cooling
B. smothering
C. oxygen dilution
D. breaking the chain reaction
[单项选择]A class C fire would be burning（）.
A. fuel oil
B. wood
C. celluloid
D. electrical insulation
[单项选择]The best method of extinguishing a class A fire is to （）.
A. remove oxygen from the area
B. smother fire with foam
C. smother fire with CO2
D. cool fuel below ignition temperature
[单项选择]The class of fire on which a blanketing effect is essential to extinguish the fire is （）.
A. class A
B. class B
C. class C
D. class D
[单项选择]A class B fire is most successfully fought by（）.
A. preventing oxygen from reaching the burning material
B. cooling the burning material below its ignition temperature
C. using the extinguishing agent to make the burning material fire-resistant
D. using the extinguishing agent to absorb the heat
[单项选择]If ignited，which material would be a class B fire?（）
A. Magnesium
B. Paper
C. Wood
D. Diesel Oil
