FCTC Fire Behavior and Service Terminology 5 — Questions and Answers
Question 1: Which term refers to the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit?
- Calorie
- Joule
- BTU (Correct answer)
- Watt
Correct answer: BTU
A British Thermal Unit (BTU) is defined as the heat needed to raise one pound of water by 1°F and is a standard unit in fire engineering.
Question 2: In the fire tetrahedron model, which element replaced the base of the older fire triangle?
- Oxygen
- Fuel
- Heat
- Chemical chain reaction (Correct answer)
Correct answer: Chemical chain reaction
The fire tetrahedron added the chemical chain reaction as the fourth element to the original fire triangle of heat, fuel, and oxygen.
Question 3: What term describes the transfer of heat through direct contact between molecules of matter?
- Convection
- Radiation
- Conduction (Correct answer)
- Combustion
Correct answer: Conduction
Conduction is heat transfer through direct molecular contact, such as heat traveling through a metal door or structural beam.
Question 4: What is the specific gravity of a flammable liquid that is LESS than 1, indicating it will do what in water?
- Sink and mix
- Sink but not mix
- Float on top (Correct answer)
- Evaporate instantly
Correct answer: Float on top
Flammable liquids with a specific gravity less than 1 are lighter than water and will float on the surface, allowing fire to spread over water.
Question 5: Which term describes the concentration range in which a flammable gas will ignite when mixed with air?
- Vapor density range
- Flammable (explosive) range (Correct answer)
- Flash point range
- Combustion threshold
Correct answer: Flammable (explosive) range
The flammable or explosive range is bounded by the Lower Explosive Limit (LEL) and Upper Explosive Limit (UEL), defining concentrations that support ignition.
Question 6: What fire service term refers to the process of removing combustible material to stop fire spread?
- Suppression
- Ventilation
- Exposure protection
- Fuel removal (Correct answer)
Correct answer: Fuel removal
Fuel removal (also called fuel separation) is a fire control method that eliminates the fire tetrahedron's fuel side by removing combustibles from the fire's path.
Question 7: When a fire is described as 'ventilation-controlled,' what does this mean?
- The fire has adequate oxygen and is limited only by fuel availability
- The fire's growth is restricted by insufficient oxygen supply (Correct answer)
- Firefighters have opened ventilation holes to control the fire
- The fire is burning in a fully open environment
Correct answer: The fire's growth is restricted by insufficient oxygen supply
A ventilation-controlled fire is one where growth is limited by the available air supply rather than fuel, producing large amounts of unburned gases.
FCTC Fire Behavior and Service Terminology 5
Which term refers to the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit?