TFM04 – Extinguisher Type A (Fixed Systems)
Practice Exam
120 Questions & Answers with Rationales — Piping & Fittings, Testing & Maintenance
Frequencies, Fixed Fire Protection Systems, Applicable NFPA Standards, and Fire
Classification
1. Which class of fire involves ordinary combustible materials such as wood,
paper, and cloth?
A. Class A
B. Class B
C. Class C
D. Class D
Answer: A
Rationale: Class A fires involve ordinary combustibles like wood, paper, cloth, rubber,
and many plastics, which leave ash after burning.
2. A fire involving gasoline or other flammable liquids is classified as:
A. Class A
B. Class B
C. Class C
D. Class K
Answer: B
Rationale: Class B fires involve flammable and combustible liquids and gases, such as
gasoline, oil, and solvents.
3. Fires involving energized electrical equipment are classified as:
A. Class A
B. Class B
C. Class C
D. Class D
Answer: C
Rationale: Class C designates fires involving energized electrical equipment; once the
equipment is de-energized, the fire may be reclassified based on the fuel involved.
,4. Which class of fire involves combustible metals such as magnesium, titanium,
and sodium?
A. Class A
B. Class B
C. Class C
D. Class D
Answer: D
Rationale: Class D fires involve combustible metals, which require specialized dry
powder extinguishing agents rather than water or standard dry chemical agents.
5. Fires involving cooking oils and fats in commercial kitchen appliances are
classified as:
A. Class A
B. Class B
C. Class C
D. Class K
Answer: D
Rationale: Class K fires involve combustible cooking media such as vegetable and
animal oils and fats, typically found in commercial cooking appliances.
6. Why can Class K fires re-ignite easily if not properly extinguished?
A. They burn at extremely low temperatures
B. Cooking oils retain heat well above their autoignition temperature
C. They are electrically energized
D. They contain combustible metal particles
Answer: B
Rationale: Cooking oils and fats can remain heated well above their autoignition
temperature, allowing them to reignite unless the agent used cools and forms a
vapor-sealing layer over the fuel.
,7. A fire that begins as a Class C (energized electrical) fire but continues to burn
after the power is shut off should be reclassified based on:
A. The extinguisher used
B. The fuel that continues to burn
C. The location of the fire
D. The time it takes to extinguish
Answer: B
Rationale: Once electrical equipment is de-energized, the hazard classification
depends on the remaining combustible fuel, such as insulation (Class A) or oil (Class
B).
8. Which agent characteristic makes an extinguishing method appropriate for
Class K hazards?
A. High electrical conductivity
B. Ability to saponify hot cooking oils and fats
C. Ability to smother metal fires
D. High flow rate for large open areas
Answer: B
Rationale: Wet chemical agents used on Class K fires react with the fatty acids in
cooking oil (saponification), forming a soap-like foam blanket that cools and seals the
surface.
9. Sand or specialized dry powder agents are typically used on which class of
fire?
A. Class A
B. Class B
C. Class C
D. Class D
Answer: D
Rationale: Class D combustible metal fires require special dry powder agents (not
standard dry chemical) that smother the metal and do not react with it.
, 10. A fire involving both ordinary combustibles and energized electrical wiring
within the same structure would most accurately be classified as:
A. Class A only
B. Class C only
C. A combination hazard, addressed based on each fuel present
D. Class K
Answer: C
Rationale: Structures often present multiple fire classes simultaneously; technicians
must recognize each hazard present so the extinguishing system or agent selected is
compatible with all classes involved.
11. Which NFPA standard governs the design and installation of carbon dioxide
fire extinguishing systems?
A. NFPA 10
B. NFPA 12
C. NFPA 17
D. NFPA 2001
Answer: B
Rationale: NFPA 12 is the Standard on Carbon Dioxide Extinguishing Systems.
12. Dry chemical extinguishing systems are governed by which standard?
A. NFPA 11
B. NFPA 12A
C. NFPA 17
D. NFPA 750
Answer: C
Rationale: NFPA 17 is the Standard for Dry Chemical Extinguishing Systems.
13. Wet chemical extinguishing systems, commonly used to protect commercial
cooking equipment, are governed by:
A. NFPA 17
B. NFPA 17A
C. NFPA 96
D. NFPA 10
Answer: B
Rationale: NFPA 17A is the Standard for Wet Chemical Extinguishing Systems.
Practice Exam
120 Questions & Answers with Rationales — Piping & Fittings, Testing & Maintenance
Frequencies, Fixed Fire Protection Systems, Applicable NFPA Standards, and Fire
Classification
1. Which class of fire involves ordinary combustible materials such as wood,
paper, and cloth?
A. Class A
B. Class B
C. Class C
D. Class D
Answer: A
Rationale: Class A fires involve ordinary combustibles like wood, paper, cloth, rubber,
and many plastics, which leave ash after burning.
2. A fire involving gasoline or other flammable liquids is classified as:
A. Class A
B. Class B
C. Class C
D. Class K
Answer: B
Rationale: Class B fires involve flammable and combustible liquids and gases, such as
gasoline, oil, and solvents.
3. Fires involving energized electrical equipment are classified as:
A. Class A
B. Class B
C. Class C
D. Class D
Answer: C
Rationale: Class C designates fires involving energized electrical equipment; once the
equipment is de-energized, the fire may be reclassified based on the fuel involved.
,4. Which class of fire involves combustible metals such as magnesium, titanium,
and sodium?
A. Class A
B. Class B
C. Class C
D. Class D
Answer: D
Rationale: Class D fires involve combustible metals, which require specialized dry
powder extinguishing agents rather than water or standard dry chemical agents.
5. Fires involving cooking oils and fats in commercial kitchen appliances are
classified as:
A. Class A
B. Class B
C. Class C
D. Class K
Answer: D
Rationale: Class K fires involve combustible cooking media such as vegetable and
animal oils and fats, typically found in commercial cooking appliances.
6. Why can Class K fires re-ignite easily if not properly extinguished?
A. They burn at extremely low temperatures
B. Cooking oils retain heat well above their autoignition temperature
C. They are electrically energized
D. They contain combustible metal particles
Answer: B
Rationale: Cooking oils and fats can remain heated well above their autoignition
temperature, allowing them to reignite unless the agent used cools and forms a
vapor-sealing layer over the fuel.
,7. A fire that begins as a Class C (energized electrical) fire but continues to burn
after the power is shut off should be reclassified based on:
A. The extinguisher used
B. The fuel that continues to burn
C. The location of the fire
D. The time it takes to extinguish
Answer: B
Rationale: Once electrical equipment is de-energized, the hazard classification
depends on the remaining combustible fuel, such as insulation (Class A) or oil (Class
B).
8. Which agent characteristic makes an extinguishing method appropriate for
Class K hazards?
A. High electrical conductivity
B. Ability to saponify hot cooking oils and fats
C. Ability to smother metal fires
D. High flow rate for large open areas
Answer: B
Rationale: Wet chemical agents used on Class K fires react with the fatty acids in
cooking oil (saponification), forming a soap-like foam blanket that cools and seals the
surface.
9. Sand or specialized dry powder agents are typically used on which class of
fire?
A. Class A
B. Class B
C. Class C
D. Class D
Answer: D
Rationale: Class D combustible metal fires require special dry powder agents (not
standard dry chemical) that smother the metal and do not react with it.
, 10. A fire involving both ordinary combustibles and energized electrical wiring
within the same structure would most accurately be classified as:
A. Class A only
B. Class C only
C. A combination hazard, addressed based on each fuel present
D. Class K
Answer: C
Rationale: Structures often present multiple fire classes simultaneously; technicians
must recognize each hazard present so the extinguishing system or agent selected is
compatible with all classes involved.
11. Which NFPA standard governs the design and installation of carbon dioxide
fire extinguishing systems?
A. NFPA 10
B. NFPA 12
C. NFPA 17
D. NFPA 2001
Answer: B
Rationale: NFPA 12 is the Standard on Carbon Dioxide Extinguishing Systems.
12. Dry chemical extinguishing systems are governed by which standard?
A. NFPA 11
B. NFPA 12A
C. NFPA 17
D. NFPA 750
Answer: C
Rationale: NFPA 17 is the Standard for Dry Chemical Extinguishing Systems.
13. Wet chemical extinguishing systems, commonly used to protect commercial
cooking equipment, are governed by:
A. NFPA 17
B. NFPA 17A
C. NFPA 96
D. NFPA 10
Answer: B
Rationale: NFPA 17A is the Standard for Wet Chemical Extinguishing Systems.
