3B Fire Protection General 3C Fire
Protection Practice Exam Questions and
answers latest update
1. The four components of the fire tetrahedron are:
o A. Fuel, Heat, Nitrogen, Chemical Chain Reaction
o B. Fuel, Heat, Oxygen, and Chemical Chain Reaction
o C. Fuel, Spark, Oxygen, and Sustained Combustion
o D. Wood, Heat, Air, and Flame
correct answer: B. Fuel, Heat, Oxygen, and Chemical Chain Reaction
explanation: The fire tetrahedron model includes these four essential
elements required for fire to exist and sustain itself.
2. What is the process called when a solid changes directly to a gas without passing
through a liquid phase?
o A. Evaporation
o B. Condensation
o C. Sublimation
o D. Pyrolysis
correct answer: C. Sublimation
explanation: Sublimation is the phase transition where a substance goes
from a solid directly to a gas. An example is dry ice (solid CO₂) turning into
carbon dioxide gas.
3. What is the primary mechanism of heat transfer responsible for pre-heating fuels
above a fire?
o A. Conduction
o B. Convection
o C. Radiation
o D. Direct Flame Contact
correct answer: B. Convection
explanation: Convection is the transfer of heat by the movement of a fluid
(like hot gases and smoke). This is the main process that carries heat
upward and spreads fire to fuels above the initial burn.
,4. At what temperature (Fahrenheit) does ordinary combustible material typically
ignite?
o A. 212°F
o B. 350°F
o C. 500°F
o D. 1,000°F
correct answer: C. 500°F
explanation: Ordinary combustibles like wood and paper generally reach
their ignition temperature and begin to pyrolyze at approximately 500°F
(260°C).
5. What is the minimum oxygen concentration typically required to support flaming
combustion?
o A. 5%
o B. 10%
o C. 16%
o D. 21%
correct answer: C. 16%
explanation: While normal air contains about 21% oxygen, most flaming
combustion can no longer be sustained when the oxygen concentration
drops below approximately 16%.
6. What term describes the temperature at which a liquid gives off enough vapor to
form an ignitable mixture with air?
o A. Fire point
o B. Auto-ignition temperature
o C. Flash point
o D. Boiling point
correct answer: C. Flash point
explanation: The flash point is the minimum temperature at which a liquid
produces enough vapor to flash in the presence of an ignition source. It is
a key indicator of a liquid's flammability hazard.
7. What is the primary chemical compound produced during incomplete
combustion that poses a significant health risk?
o A. Carbon dioxide (CO₂)
o B. Water vapor (H₂O)
o C. Carbon monoxide (CO)
o D. Hydrogen cyanide (HCN)
correct answer: C. Carbon monoxide (CO)
explanation: Carbon monoxide is a toxic, odorless gas produced when
, combustion is inefficient due to insufficient oxygen. It is a leading cause of
fire-related fatalities.
8. What is the difference between a deflagration and a detonation?
o A. Deflagration is supersonic; detonation is subsonic.
o B. Deflagration propagates through shock compression; detonation
through heat transfer.
o C. A deflagration is subsonic combustion propagating through heat
transfer, while a detonation is supersonic combustion propagating
through shock compression.
o D. They are synonymous terms.
correct answer: C. A deflagration is subsonic combustion propagating
through heat transfer, while a detonation is supersonic combustion
propagating through shock compression.
explanation: The key distinction is the speed of the combustion wave
relative to the speed of sound (subsonic vs. supersonic) and the
mechanism of propagation.
9. What is the primary extinguishing mechanism when using water on a Class A fire?
o A. Smothering (oxygen exclusion)
o B. Chemical flame inhibition
o C. Fuel removal
o D. Cooling
correct answer: D. Cooling
explanation: Water's main effect on Class A fires (ordinary combustibles)
is cooling. It absorbs heat from the fuel, lowering the temperature below
its ignition point.
10. What are pyrolysis products?
o A. The solid residue left after a fire.
o B. Inert gases used in fire suppression.
o C. Combustible gases released when a solid fuel is heated.
o D. The ash from complete combustion.
correct answer: C. Combustible gases released when a solid fuel is
heated.
explanation: Pyrolysis is the chemical decomposition of a solid fuel by
heat. This process releases volatile, combustible gases that mix with air
and are what actually ignite and burn in a flame.
11. What is the primary purpose of a fire alarm system?
Protection Practice Exam Questions and
answers latest update
1. The four components of the fire tetrahedron are:
o A. Fuel, Heat, Nitrogen, Chemical Chain Reaction
o B. Fuel, Heat, Oxygen, and Chemical Chain Reaction
o C. Fuel, Spark, Oxygen, and Sustained Combustion
o D. Wood, Heat, Air, and Flame
correct answer: B. Fuel, Heat, Oxygen, and Chemical Chain Reaction
explanation: The fire tetrahedron model includes these four essential
elements required for fire to exist and sustain itself.
2. What is the process called when a solid changes directly to a gas without passing
through a liquid phase?
o A. Evaporation
o B. Condensation
o C. Sublimation
o D. Pyrolysis
correct answer: C. Sublimation
explanation: Sublimation is the phase transition where a substance goes
from a solid directly to a gas. An example is dry ice (solid CO₂) turning into
carbon dioxide gas.
3. What is the primary mechanism of heat transfer responsible for pre-heating fuels
above a fire?
o A. Conduction
o B. Convection
o C. Radiation
o D. Direct Flame Contact
correct answer: B. Convection
explanation: Convection is the transfer of heat by the movement of a fluid
(like hot gases and smoke). This is the main process that carries heat
upward and spreads fire to fuels above the initial burn.
,4. At what temperature (Fahrenheit) does ordinary combustible material typically
ignite?
o A. 212°F
o B. 350°F
o C. 500°F
o D. 1,000°F
correct answer: C. 500°F
explanation: Ordinary combustibles like wood and paper generally reach
their ignition temperature and begin to pyrolyze at approximately 500°F
(260°C).
5. What is the minimum oxygen concentration typically required to support flaming
combustion?
o A. 5%
o B. 10%
o C. 16%
o D. 21%
correct answer: C. 16%
explanation: While normal air contains about 21% oxygen, most flaming
combustion can no longer be sustained when the oxygen concentration
drops below approximately 16%.
6. What term describes the temperature at which a liquid gives off enough vapor to
form an ignitable mixture with air?
o A. Fire point
o B. Auto-ignition temperature
o C. Flash point
o D. Boiling point
correct answer: C. Flash point
explanation: The flash point is the minimum temperature at which a liquid
produces enough vapor to flash in the presence of an ignition source. It is
a key indicator of a liquid's flammability hazard.
7. What is the primary chemical compound produced during incomplete
combustion that poses a significant health risk?
o A. Carbon dioxide (CO₂)
o B. Water vapor (H₂O)
o C. Carbon monoxide (CO)
o D. Hydrogen cyanide (HCN)
correct answer: C. Carbon monoxide (CO)
explanation: Carbon monoxide is a toxic, odorless gas produced when
, combustion is inefficient due to insufficient oxygen. It is a leading cause of
fire-related fatalities.
8. What is the difference between a deflagration and a detonation?
o A. Deflagration is supersonic; detonation is subsonic.
o B. Deflagration propagates through shock compression; detonation
through heat transfer.
o C. A deflagration is subsonic combustion propagating through heat
transfer, while a detonation is supersonic combustion propagating
through shock compression.
o D. They are synonymous terms.
correct answer: C. A deflagration is subsonic combustion propagating
through heat transfer, while a detonation is supersonic combustion
propagating through shock compression.
explanation: The key distinction is the speed of the combustion wave
relative to the speed of sound (subsonic vs. supersonic) and the
mechanism of propagation.
9. What is the primary extinguishing mechanism when using water on a Class A fire?
o A. Smothering (oxygen exclusion)
o B. Chemical flame inhibition
o C. Fuel removal
o D. Cooling
correct answer: D. Cooling
explanation: Water's main effect on Class A fires (ordinary combustibles)
is cooling. It absorbs heat from the fuel, lowering the temperature below
its ignition point.
10. What are pyrolysis products?
o A. The solid residue left after a fire.
o B. Inert gases used in fire suppression.
o C. Combustible gases released when a solid fuel is heated.
o D. The ash from complete combustion.
correct answer: C. Combustible gases released when a solid fuel is
heated.
explanation: Pyrolysis is the chemical decomposition of a solid fuel by
heat. This process releases volatile, combustible gases that mix with air
and are what actually ignite and burn in a flame.
11. What is the primary purpose of a fire alarm system?
