CFM Fire Behavior & Combustion Principles 1 — Questions and Answers
Question 1: What are the three components of the fire triangle?
- Heat, fuel, and oxygen (Correct answer)
- Fuel, spark, and air
- Heat, combustion, and air
- Oxygen, carbon, and heat
Correct answer: Heat, fuel, and oxygen
The fire triangle consists of heat, fuel, and oxygen — all three must be present simultaneously for fire to occur and be sustained.
Question 2: The lowest temperature at which a liquid produces enough vapor to ignite momentarily when exposed to an open flame is called:
- Auto-ignition temperature
- Flash point (Correct answer)
- Boiling point
- Combustion threshold
Correct answer: Flash point
The flash point is the lowest temperature at which a liquid produces sufficient vapor to ignite momentarily when exposed to an external ignition source such as an open flame.
Question 3: Which type of heat transfer occurs when heat moves through direct physical contact between materials?
- Convection
- Radiation
- Conduction (Correct answer)
- Pyrolysis
Correct answer: Conduction
Conduction transfers heat through direct physical contact between materials, such as a hot metal beam heating adjacent structural members.
Question 4: The phenomenon where all combustible materials in a confined space simultaneously ignite due to accumulated radiant heat is called:
- Backdraft
- Flashover (Correct answer)
- Rollover
- Pyrolysis
Correct answer: Flashover
Flashover occurs when radiant heat causes all combustible materials in a compartment to simultaneously ignite, rapidly transitioning the fire to full room involvement.
Question 5: Which class of fire involves combustible metals such as magnesium, sodium, and titanium?
- Class A
- Class B
- Class C
- Class D (Correct answer)
Correct answer: Class D
Class D fires involve combustible metals such as magnesium, sodium, potassium, and titanium, which require specialized dry powder extinguishing agents.
Question 6: What term describes the transfer of heat through electromagnetic waves without requiring a physical medium or direct contact?
- Conduction
- Convection
- Radiation (Correct answer)
- Transmission
Correct answer: Radiation
Radiation transfers heat through electromagnetic waves and does not require direct contact or a medium, allowing heat energy to travel through open space.
Question 7: Which statement correctly describes the minimum concentration of flammable vapor in air required to sustain combustion?
- It is called the upper explosive limit (UEL)
- It is called the lower explosive limit (LEL) (Correct answer)
- It is called the flash point
- It is called the auto-ignition temperature
Correct answer: It is called the lower explosive limit (LEL)
The lower explosive limit (LEL) is the minimum concentration of flammable vapor in air below which the mixture is too lean to sustain combustion.
CFM Fire Behavior & Combustion Principles 1
What are the three components of the fire triangle?