Fire Behavior and Combustion Quiz #4

Chapters 11-13

How much thermal radiation typically comes from the soot contained in a flame?

A) 80 percent

B) 75 percent

C) 60 percent

D) 55 percent

A) 80 percent

Smoke exiting a burning building appears very light in color. Which of the following aerosols are responsible for this appearance?

A) Carbonaceous solid particles

B) Hydrogen particles

C) Liquid droplets

D) Carbon dioxide droplets

C) Liquid droplets

Why is understanding the formation of soot and sooting tendency of fuels of particular importance to the aviation industry?

A) Higher-sooting fuels may lead to poor fuel economy and can foul aircraft engines.

B) Higher-sooting fuels may contribute to environmental pollution.

C) Lower-sooting fuels may lead to less available engine power.

D) Lower-sooting fuels may not have enough vapor pressure to provide needed lift for an aircraft

A) Higher-sooting fuels may lead to poor fuel economy and can foul aircraft engines.

Why does methanol burn with practically no particulate production?

A) Because it is a flaming fuel that contains oxygen

B) Because it is a nonflaming fuel that contains oxygen

C) Because it is a flaming fuel that does not contain oxygen

D) Because it is a nonflaming fuel that does not contain oxygen

A) Because it is a flaming fuel that contains oxygen

How does ventilation impact smoke yield?

A) Smoke yields decrease significantly as the fire proceeds from well-ventilated to underventilated.

B) Smoke yields from underventilated fires are approximately double those from well-ventilated flaming of the same materials.

C) Smoke yields from well-ventilated fires are approximately double those from underventilated fires of the same materials.

D) Smoke yields increase significantly as higher amounts of ventilation are introduced into the fire plume

B) Smoke yields from underventilated fires are approximately double those from well-ventilated flaming of the same materials.

How do infrared-sensitive video cameras increase the ability of firefighters to “see” through smoke?

A) The infrared radiation wavelengths emitted from heated objects have longer wavelengths than visible light, which prevents particle scattering.

B) The infrared radiation wavelengths emitted from heated objects have shorter wavelengths than visible light, which prevents particle scattering.

C) The infrared radiation wavelengths emitted from heated objects have longer wavelengths than visible light, which causes smoke particles to scatter.

D) The infrared radiation wavelengths emitted from heated objects have shorter wavelengths than visible light, which causes smoke particles to scatter

A) The infrared radiation wavelengths emitted from heated objects have longer wavelengths than visible light, which prevents particle scattering.

In smoldering fires, why is the oxidation zone very thin and cool relative to flaming fires?

A) Because heat-generated buoyancy lifts heat away from the point of pyrolysis

B) Because effluent temperatures have lifted away from the smoldering material

C) Because ventilation in the room has dispersed oxygen toward warmer areas

D) Because no flames are present

D) Because no flames are present

Which type of smoke alarm employs voltage across a sensing chamber in order to detect smoke particles?

A) Non-ionizing smoke alarm

B) Ionization smoke alarm

C) Photoelectric smoke alarm

D) Calorimetric smoke alarm

B) Ionization smoke alarm

Which CO detection device is advantageous for residential use because its output is proportional to CO concentration and it is operated at room temperature?

A) Electrochemical CO sensor

B) Semiconductor Electrical Resistance Detector

C) Photoionization alarm

D) Ionizing CO detector

A) Electrochemical CO sensor

A light emitting diode (LED) would be found in which type of smoke alarm?

A) Polarizing smoke alarm

B) Photoelectric smoke alarm

C) Ionization smoke alarm

D) Electrochemical smoke alarm

B) Photoelectric smoke alarm

Why should homeowners be advised to place smoke alarms high on the wall or on the ceiling of each bedroom?

A) Because the natural flow of warm fire effluent travels upward and will reach high levels of walls and ceilings prior to lower areas of the room

B) Because alarms placed in other areas of the home may not be audible to bedroom occupants due to dense smoke

C) Because an open bedroom door could increase fire growth that destroys an alarm installed at a lower level

D) Because alarms installed at lower levels are difficult for occupants to see

A) Because the natural flow of warm fire effluent travels upward and will reach high levels of walls and ceilings prior to lower areas of the room

When HF, HBr, or HCl is present in smoke, what atoms are likely to be present?

A) Oxygen, fluorine, or chlorine

B) Hydrogen, oxygen, or nitrogen

C) Fluorine, bromine, or chlorine

D) Phosgene, chlorine, or carbon

C) Fluorine, bromine, or chlorine

What is the available safe escape time?

A) The calculated time interval between flashover and total room involvement, preventing occupant escape

B) The calculated time interval between the time of ignition and the time that fire conditions would incapacitate an occupant

C) The calculated time interval between an occupant’s recognition of fire and their attempt to extinguish it

D) The calculated time interval between an occupant’s exposure to fire products and their ability to escape

B) The calculated time interval between the time of ignition and the time that fire conditions would incapacitate an occupant

Impaired mobility and reduced clarity of thinking are examples of which type of smoke exposure effects?

A) Chronic effects

B) Toxic effects

C) Postfire effects

D) Acute effects

D) Acute effects

What molecule is formed when a CO molecule bonds to the hemoglobin in red blood cells?

A) Hydroxyhemoglobin

B) Carboxyhemoglobin

C) Hydrogen oxide

D) Carbon dioxide

B) Carboxyhemoglobin

What was the major significant finding of the Maryland forensic study on fire victims?

A) That 80 percent of victims died from second- and third-degree burns

B) That 80 percent of victims could have died as a result of carbon dioxide inhalation

C) That 80 percent of victims could have died as a result of carbon monoxide inhalation

D) That 60 percent of victims suffered from hydrogen cyanide poisoning

C) That 80 percent of victims could have died as a result of carbon monoxide inhalation

Based on laboratory studies with test animals, how is fire-generated CO toxic?

A) It is an irritant upon contact.

B) It is an asphyxiant.

C) It is a corrosive gas.

D) It is a hallucinogen

B) It is an asphyxiant.

What symptoms might a person experience when the percentage of carboxyhemoglobin increases to 20 percent in the blood stream?

A) Death within an hour

B) Severe headache, vomiting

C) Coma, collapse

D) Slight headache, dizziness

D) Slight headache, dizziness

What percentage of hemoglobin converted to carboxyhemoglobin can result in death with an hour?

A) 10 to 20 percent

B) 30 to 40 percent

C) 40 to 50 percent

D) 80 to 90 percent

D) 80 to 90 percent

Which gas has a lethal toxic potency that is approximately 20 times that of CO?

A) Carbon dioxide

B) Hydrogen cyanide

C) Phosgene

D) Aromatic hydrocarbon

B) Hydrogen cyanide

What type of materials can produce smoke containing hydrogen cyanide?

A) Highly oxygen-rich materials

B) Materials containing nitrogen

C) Carbon neutral materials

D) Hydrocarbon materials

B) Materials containing nitrogen

How does hydrogen cyanide harm the body?

A) It displaces oxygen in the blood stream, preventing circulation.

B) It prevents blood from reaching the brain, impairing motor skills and cognition.

C) It combines with body and brain cell enzymes and inactivates them so the cells can no longer accept oxygen.

D) It forms carboxyhemoglobin in the blood stream

C) It combines with body and brain cell enzymes and inactivates them so the cells can no longer accept oxygen.

How can faster and more accurate fire alarms reduce firefighter and public exposure to smoke?

A) Alerting firefighters more quickly so that they can avoid making entry during the most toxic phases of fire

B) Alerting occupants when fires are smaller and generating less smoke so that early notification to firefighters can be made

C) Alerting and automatically activating sprinkler systems so that firefighters do not have to engage

D) Alerting occupants by notifying their cellular devices of a possible fire

B) Alerting occupants when fires are smaller and generating less smoke so that early notification to firefighters can be made

Why have authorities begun banning or restricting the use of certain fire retardant chemicals?

A) Because they have been shown some indication of significant health risk

B) Because they have been shown to accelerate fire growth in certain synthetic materials

C) Because they have been proven to be ineffective

D) Because they have been proven to produce second-degree burns even at low temperatures

A) Because they have been shown some indication of significant health risk

What interior building components are most susceptible to nonthermal smoke damage?

A) Electronics

B) Wood components

C) Drywall

D) Concrete

A) Electronics

Why is understanding of limiting hazards important?

A) So firefighters can pre-plan response activities

B) So occupants and firefighters are aware of their own performance limitations

C) So mitigation activities can be focused on the most effective improvements in the safety for occupants and fire personnel

D) So structural engineers can design fireproof buildings

C) So mitigation activities can be focused on the most effective improvements in the safety for occupants and fire personnel

Which term describes the fire stage where no flames are visible and the combustible item no longer generates heat or combustion products?

A) Fire extinguishment

B) Fire control

C) Fire containment

D) Fire inerting

A) Fire extinguishment

Which items would be found in a Class A fire?

A) Cooking oil and grease

B) Electrical equipment

C) Gasoline

D) Cloth and paper

D) Cloth and paper

Which items would be found in a Class B fire?

A) Cloth and paper

B) Electrical equipment

C) Methanol

D) Magnesium

C) Methanol

Which items would be found in a Class C fire?

A) Electrical equipment

B) Wood and paper

C) Magnesium

D) Cooking oil

A) Electrical equipment

Which items would be found in a Class D fire?

A) Wood and paper

B) Magnesium

C) Cooking grease

D) Polypropylene

B) Magnesium

At what temperature range are residential sprinklers typically designed to actuate?

A) 100 °F to 175 °F

B) 135 °F to 170 °F

C) 200 °F to 250 °F

D) 300 °F to 350 °F

B) 135 °F to 170 °F

Which extinguishing agent is most desirable for use on solid combustibles because of its high heat of vaporization?

A) Carbon dioxide

B) Dry chemical

C) Water

D) Protein foam

C) Water

By what action does aqueous foam work to suppress flames from burning hydrocarbons?

A) It sinks beneath the fuel’s surface to cool heated fuels and prevent further creation of flammable gases.

B) It forms a continuous layer on top of burning fuel, cooling the surface and separating fuel vapors from air.

C) It forms small pockets of chemical layers on top of burning fuel, reducing the amount of oxygen that reacts with flammable vapors.

D) It immediately cools the entire body of fuel, reducing flammable vapor creation

B) It forms a continuous layer on top of burning fuel, cooling the surface and separating fuel vapors from air.

Which of the following liquids are nonflammable and could be considered as fire suppressants?

A) Bromine

B) Helium

C) Chlorine

D) Hydrogen

A) Bromine

Which gas is considered to be a noble gas?

A) Argon

B) Hydrogen

C) Chlorine

D) Nitrogen

A) Argon

Why is it important to evacuate any personnel not wearing SCBA from an environment where noble gas mixtures are to be applied for fire suppression?

A) Noble gases are an irritant and will cause respiratory distress.

B) Noble gases are toxic and will cause respiratory infection.

C) Noble gases dilute ambient air to the point where a person isn’t inhaling enough oxygen.

D) Noble gases are poisonous and will cause organ failure upon absorption into the respiratory tract

C) Noble gases dilute ambient air to the point where a person isn’t inhaling enough oxygen.

Why have halon 1301, 1211, and 2402 been phased out of use in many parts of the world?

A) Because of their high corrosively when exposed to fire

B) Because of their asphyxiant nature

C) Because they are among the highest ozone-depletion-potential chemicals

D) Because they are expensive to produce and use

C) Because they are among the highest ozone-depletion-potential chemicals

13. Applied with a stream or widely dispersed, which agent is mainly used to extinguish Class B and Class C fires?

A) Halon 1301

B) Carbon dioxide

C) Protein foam

D) Dry chemical powders

D) Dry chemical powders

What popular name is used for the dry chemical agent KCl?

A) Super K

B) Purple K

C) Baking soda

D) ABC

B) Purple K

What is the best tactic for extinguishment of flowing gas flames?

A) Introduce large volumes of water to keep the gas from producing flammable vapors.

B) Apply AFFF to the gas container and surroundings to prevent ignition.

C) Increase fresh air supply to the area so that oxygen concentrations are too saturated for flaming to occur.

D) Shut off the flow of gas

D) Shut off the flow of gas