更多"Dry chemical fire extinguishers are"的相关试题:
[单项选择]A portable dry chemical fire extinguisher discharges by().
A. gravity when the extinguisher is turned upside down
B. pressure from a small CO2 cartridge on the extinguisher
C. air pressure from the hand pump attached to the extinguisher
D. pressure from the reaction when water is mixed with the chemical
[单项选择]An ABC dry chemical fire extinguisher would be LEAST effective against a fire in().
A. a mattress
B. spilled liquids such as oil or paint
C. high voltage electrical gear
D. a trash can
[单项选择]An ABC dry chemical fire extinguisher would be least effective against a fire in().
A. a mattress
B. spilled liquids such as oil or paint
C. high voltage electrical gear
D. a trash can
[单项选择]An “ABC” dry chemical fire extinguisher would be LEAST effective against a fire in().
A. a mattress
B. spilled liquids such as oil or paint
C. high voltage electrical gear
D. a trash can
[单项选择]When must a dry chemical fire extinguisher be recharged?()
A. After each use
B. When the air temperature exceeds 90°F
C. Every 6 months
D. Every 12 months
[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]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]When fighting a fire with a portable dry chemical fire extinguisher,the stream should be directed().
A. over the top of the flames
B. off a bulkhead into the fire
C. in front of the fire
D. at the base of the fire
[单项选择]When dry chemical extinguishers are used to put out class B fires,there is a danger of reflash because dry chemical().
A. is not an effective agent on Class B fires
B. does little or no cooling
C. dissipates quickly
D. is rapidly absorbed by the liquid
[单项选择]One disadvantage of using regular dry chemical (sodium bicarbonate) in firefighting is that().
A. it can break down under high heat and emit noxious fumes
B. it will decompose under prolonged storage and lose its effectiveness
C. fire has been known to flash back over the surface of an oil fire
D. it is ineffective in fighting fires in high-voltage electrical equipment
[单项选择]An advantage of a dry chemical over a carbon dioxide fire extinguish is its().
A. greater range
B. effective on all types of fires
C. cleanliness
D. All of the above
[单项选择]An advantage of an ABC dry chemical over a carbon dioxide extinguisher is().
A. lack of toxicity
B. the multipurpose extinguishing ability
C. burn-back protection
D. cooling ability
[单项选择]As compared to carbon dioxide,dry chemical has which advantage?()
A. Cleaner
B. Effective on metal fires
C. Greater range
D. More cooling effect