CWH FIREFIGHTER SELECTION EXAM | LATEST EXAM QUESTIONS
AND SOLUTIONS - VERIFIED ANSWERS 2026/2027
Firefighter CWH
1. Which three elements make up the fire triangle?
A. Fuel, water, and oxygen
B. Oxygen, nitrogen, and heat
C. Heat, smoke, and fuel
D. Heat, fuel, and oxygen
D. Heat, fuel, and oxygen. Fire needs heat, fuel, and oxygen together;
removing any one of them extinguishes the fire.
2. The fire tetrahedron adds which fourth component to the fire
triangle?
A. Convection
B. Carbon dioxide
C. Uninhibited chemical chain reaction
D. Ignition temperature
C. Uninhibited chemical chain reaction. The tetrahedron includes the
self-sustaining chemical chain reaction that keeps flaming combustion
going.
1
,3. What is the approximate percentage of oxygen in normal air?
A. 21 percent
B. 25 percent
C. 19 percent
D. 16 percent
A. 21 percent. Ordinary air contains about 21 percent oxygen and 78
percent nitrogen.
4. Which method of heat transfer occurs through direct contact
between materials?
A. Convection
B. Conduction
C. Diffusion
D. Radiation
B. Conduction. Conduction moves heat through solids by direct
molecular contact.
5. Heat transfer by the movement of heated liquids or gases is called:
A. Convection
B. Radiation
C. Ignition
D. Conduction
A. Convection. Convection carries heat with the movement of hot gases
or liquids, which is why hot smoke rises.
6. Which method of heat transfer travels as electromagnetic waves
without a medium?
A. Direct flame contact
B. Convection
C. Conduction
D. Radiation
D. Radiation. Radiant heat moves in waves through space, much like
heat from the sun.
2
,7. Class A fires involve which type of material?
A. Flammable liquids
B. Combustible metals
C. Ordinary combustibles such as wood and paper
D. Energized electrical equipment
C. Ordinary combustibles such as wood and paper. Class A covers
ordinary solid combustibles like wood, cloth, paper, and plastics.
8. Class B fires involve:
A. Combustible metals
B. Flammable and combustible liquids
C. Ordinary combustibles
D. Cooking oils only
B. Flammable and combustible liquids. Class B fires involve liquids and
gases such as gasoline, oil, and propane.
9. Class C fires involve:
A. Wood and paper
B. Magnesium and titanium
C. Energized electrical equipment
D. Cooking media
C. Energized electrical equipment. Class C is energized electrical
equipment; the agent must be non-conductive.
10. Class D fires involve:
A. Flammable gases
B. Cooking oils
C. Paper products
D. Combustible metals
D. Combustible metals. Class D covers combustible metals such as
magnesium, sodium, and titanium.
3
, 11. Class K fires involve:
A. Flammable gases
B. Commercial cooking oils and fats
C. Live electrical wiring
D. Ordinary trash
B. Commercial cooking oils and fats. Class K is for vegetable oils, animal
fats, and cooking media in commercial kitchens.
12. Which extinguisher agent is safest on a Class C fire?
A. Carbon dioxide
B. Wet chemical
C. Water
D. Foam
A. Carbon dioxide. Carbon dioxide is non-conductive and leaves no
residue, making it suitable for electrical fires.
13. A water-type extinguisher must never be used on which fire?
A. Class A
B. Class B liquid or Class C electrical
C. Wood
D. Paper
B. Class B liquid or Class C electrical. Water can spread flammable
liquids and conducts electricity, creating serious hazards.
14. What does the acronym PASS stand for in extinguisher use?
A. Pull, Aim, Squeeze, Sweep
B. Point, Aim, Squeeze, Sweep
C. Pull, Attack, Spray, Stand
D. Push, Aim, Spray, Stop
A. Pull, Aim, Squeeze, Sweep. PASS reminds the operator to pull the pin,
aim at the base, squeeze the handle, and sweep side to side.
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AND SOLUTIONS - VERIFIED ANSWERS 2026/2027
Firefighter CWH
1. Which three elements make up the fire triangle?
A. Fuel, water, and oxygen
B. Oxygen, nitrogen, and heat
C. Heat, smoke, and fuel
D. Heat, fuel, and oxygen
D. Heat, fuel, and oxygen. Fire needs heat, fuel, and oxygen together;
removing any one of them extinguishes the fire.
2. The fire tetrahedron adds which fourth component to the fire
triangle?
A. Convection
B. Carbon dioxide
C. Uninhibited chemical chain reaction
D. Ignition temperature
C. Uninhibited chemical chain reaction. The tetrahedron includes the
self-sustaining chemical chain reaction that keeps flaming combustion
going.
1
,3. What is the approximate percentage of oxygen in normal air?
A. 21 percent
B. 25 percent
C. 19 percent
D. 16 percent
A. 21 percent. Ordinary air contains about 21 percent oxygen and 78
percent nitrogen.
4. Which method of heat transfer occurs through direct contact
between materials?
A. Convection
B. Conduction
C. Diffusion
D. Radiation
B. Conduction. Conduction moves heat through solids by direct
molecular contact.
5. Heat transfer by the movement of heated liquids or gases is called:
A. Convection
B. Radiation
C. Ignition
D. Conduction
A. Convection. Convection carries heat with the movement of hot gases
or liquids, which is why hot smoke rises.
6. Which method of heat transfer travels as electromagnetic waves
without a medium?
A. Direct flame contact
B. Convection
C. Conduction
D. Radiation
D. Radiation. Radiant heat moves in waves through space, much like
heat from the sun.
2
,7. Class A fires involve which type of material?
A. Flammable liquids
B. Combustible metals
C. Ordinary combustibles such as wood and paper
D. Energized electrical equipment
C. Ordinary combustibles such as wood and paper. Class A covers
ordinary solid combustibles like wood, cloth, paper, and plastics.
8. Class B fires involve:
A. Combustible metals
B. Flammable and combustible liquids
C. Ordinary combustibles
D. Cooking oils only
B. Flammable and combustible liquids. Class B fires involve liquids and
gases such as gasoline, oil, and propane.
9. Class C fires involve:
A. Wood and paper
B. Magnesium and titanium
C. Energized electrical equipment
D. Cooking media
C. Energized electrical equipment. Class C is energized electrical
equipment; the agent must be non-conductive.
10. Class D fires involve:
A. Flammable gases
B. Cooking oils
C. Paper products
D. Combustible metals
D. Combustible metals. Class D covers combustible metals such as
magnesium, sodium, and titanium.
3
, 11. Class K fires involve:
A. Flammable gases
B. Commercial cooking oils and fats
C. Live electrical wiring
D. Ordinary trash
B. Commercial cooking oils and fats. Class K is for vegetable oils, animal
fats, and cooking media in commercial kitchens.
12. Which extinguisher agent is safest on a Class C fire?
A. Carbon dioxide
B. Wet chemical
C. Water
D. Foam
A. Carbon dioxide. Carbon dioxide is non-conductive and leaves no
residue, making it suitable for electrical fires.
13. A water-type extinguisher must never be used on which fire?
A. Class A
B. Class B liquid or Class C electrical
C. Wood
D. Paper
B. Class B liquid or Class C electrical. Water can spread flammable
liquids and conducts electricity, creating serious hazards.
14. What does the acronym PASS stand for in extinguisher use?
A. Pull, Aim, Squeeze, Sweep
B. Point, Aim, Squeeze, Sweep
C. Pull, Attack, Spray, Stand
D. Push, Aim, Spray, Stop
A. Pull, Aim, Squeeze, Sweep. PASS reminds the operator to pull the pin,
aim at the base, squeeze the handle, and sweep side to side.
4
