NFPA 921 FIRE AND EXPLOSION INVESTIGATIONS EXAM
LATEST 2025 WITH CORRECT QUESTIONS AND DETAILED
ANSWERS/ALREADY GRADED A+
Absolute Temperature - CORRECT ANSWER-A temperature measured in Kelvins
(K) or Rankines (R).
Accelerant - CORRECT ANSWER-A fuel or oxidizer, often an ignitible liquid,
intentionally used to initiate a fire or increase the rate of growth or spread of fire.
Accident - CORRECT ANSWER-An unplanned event that interrupts an activity
and sometimes causes injury or damage or a chance occurrence arising from
unknown causes; an unexpected happening due to carelessness, ignorance, and
the like.
Active Fire Protection System - CORRECT ANSWER-A system that uses moving
mechanical or electrical parts to achieve a fire protection goal.
Ambient - CORRECT ANSWER-Someone's or something's surroundings,
especially as they pertain to the local environment; for example, ambient air and
ambient temperature.
,Ampacity - CORRECT ANSWER-The maximum current, in amperes, that a
conductor can carry continuously under the conditions of use without exceeding
its temperature rating.
Ampere - CORRECT ANSWER-The unit of electric current that is equivalent to a
flow of one coulomb per second; one coulomb is defined as 6.24 × 1018
electrons.
Arc - CORRECT ANSWER-A high-temperature luminous electric discharge across
a gap or through a medium such as charred insulation.
Arc Mapping - CORRECT ANSWER-The systematic evaluation of the electrical
circuit configuration, spatial relationship of the circuit components, and
identification of electrical arc sites to assist in the identification of the area of
origin and analysis of the fire's spread.
Arc Site - CORRECT ANSWER-The location on a conductor with localized damage
that resulted from an electrical arc.
Arcing Through Char - CORRECT ANSWER-Arcing associated with a matrix of
charred material (e.g., charred conductor insulation) that acts as a
semiconductive medium.
,Area of Origin - CORRECT ANSWER-A structure, part of a structure, or general
geographic location within a fire scene, in which the "point of origin" of a fire or
explosion is reasonably believed to be located.
Arrow Pattern - CORRECT ANSWER-A fire pattern displayed on the cross-
section of a burned wooden structural member.
Arson - CORRECT ANSWER-The crime of maliciously and intentionally, or
recklessly, starting a fire or causing an explosion.
Autoignition - CORRECT ANSWER-Initiation of combustion by heat but without a
spark or flame.
Autoignition Temperature - CORRECT ANSWER-The lowest temperature at
which a combustible material ignites in air without a spark or flame.
Approved - CORRECT ANSWER-Acceptable to the authority having jurisdiction.
Guide - CORRECT ANSWER-A document that is advisory or informative in nature
and that contains only nonmandatory provisions. A _____ may contain mandatory
statements such as when a _____ can be used, but the document as a whole is
not suitable for adoption into law.
Recommended Practice - CORRECT ANSWER-A document that is similar in
content and structure to a code or standard but that contains only nonmandatory
, provisions using the word "should" to indicate recommendations in the body of
the text.
Standard - CORRECT ANSWER-An NFPA Standard, the main text of which
contains only mandatory provisions using the word "shall" to indicate
requirements and that is in a form generally suitable for mandatory reference by
another standard or code or for adoption into law. When used in a generic sense,
such as in the phrase "standards development process" or "standards
development activities," the term "standards" includes all NFPA Standards,
including Codes, Standards, Recommended Practices, and Guides.
Code - CORRECT ANSWER-A standard that is an extensive compilation of
provisions covering broad subject matter or that is suitable for adoption into law
independently of other codes and standards.
Backdraft - CORRECT ANSWER-A deflagration resulting from the sudden
introduction of air into a confined space containing oxygen- deficient products of
incomplete combustion.
Bead - CORRECT ANSWER-A rounded globule of re-solidified metal at the end of
the remains of an electrical conductor that was caused by arcing and is
characterized by a sharp line of demarcation between the melted and unmelted
conductor surfaces.
Blast Pressure Front - CORRECT ANSWER-The expanding leading edge of an
explosion reaction that separates a major difference in pressure between normal
LATEST 2025 WITH CORRECT QUESTIONS AND DETAILED
ANSWERS/ALREADY GRADED A+
Absolute Temperature - CORRECT ANSWER-A temperature measured in Kelvins
(K) or Rankines (R).
Accelerant - CORRECT ANSWER-A fuel or oxidizer, often an ignitible liquid,
intentionally used to initiate a fire or increase the rate of growth or spread of fire.
Accident - CORRECT ANSWER-An unplanned event that interrupts an activity
and sometimes causes injury or damage or a chance occurrence arising from
unknown causes; an unexpected happening due to carelessness, ignorance, and
the like.
Active Fire Protection System - CORRECT ANSWER-A system that uses moving
mechanical or electrical parts to achieve a fire protection goal.
Ambient - CORRECT ANSWER-Someone's or something's surroundings,
especially as they pertain to the local environment; for example, ambient air and
ambient temperature.
,Ampacity - CORRECT ANSWER-The maximum current, in amperes, that a
conductor can carry continuously under the conditions of use without exceeding
its temperature rating.
Ampere - CORRECT ANSWER-The unit of electric current that is equivalent to a
flow of one coulomb per second; one coulomb is defined as 6.24 × 1018
electrons.
Arc - CORRECT ANSWER-A high-temperature luminous electric discharge across
a gap or through a medium such as charred insulation.
Arc Mapping - CORRECT ANSWER-The systematic evaluation of the electrical
circuit configuration, spatial relationship of the circuit components, and
identification of electrical arc sites to assist in the identification of the area of
origin and analysis of the fire's spread.
Arc Site - CORRECT ANSWER-The location on a conductor with localized damage
that resulted from an electrical arc.
Arcing Through Char - CORRECT ANSWER-Arcing associated with a matrix of
charred material (e.g., charred conductor insulation) that acts as a
semiconductive medium.
,Area of Origin - CORRECT ANSWER-A structure, part of a structure, or general
geographic location within a fire scene, in which the "point of origin" of a fire or
explosion is reasonably believed to be located.
Arrow Pattern - CORRECT ANSWER-A fire pattern displayed on the cross-
section of a burned wooden structural member.
Arson - CORRECT ANSWER-The crime of maliciously and intentionally, or
recklessly, starting a fire or causing an explosion.
Autoignition - CORRECT ANSWER-Initiation of combustion by heat but without a
spark or flame.
Autoignition Temperature - CORRECT ANSWER-The lowest temperature at
which a combustible material ignites in air without a spark or flame.
Approved - CORRECT ANSWER-Acceptable to the authority having jurisdiction.
Guide - CORRECT ANSWER-A document that is advisory or informative in nature
and that contains only nonmandatory provisions. A _____ may contain mandatory
statements such as when a _____ can be used, but the document as a whole is
not suitable for adoption into law.
Recommended Practice - CORRECT ANSWER-A document that is similar in
content and structure to a code or standard but that contains only nonmandatory
, provisions using the word "should" to indicate recommendations in the body of
the text.
Standard - CORRECT ANSWER-An NFPA Standard, the main text of which
contains only mandatory provisions using the word "shall" to indicate
requirements and that is in a form generally suitable for mandatory reference by
another standard or code or for adoption into law. When used in a generic sense,
such as in the phrase "standards development process" or "standards
development activities," the term "standards" includes all NFPA Standards,
including Codes, Standards, Recommended Practices, and Guides.
Code - CORRECT ANSWER-A standard that is an extensive compilation of
provisions covering broad subject matter or that is suitable for adoption into law
independently of other codes and standards.
Backdraft - CORRECT ANSWER-A deflagration resulting from the sudden
introduction of air into a confined space containing oxygen- deficient products of
incomplete combustion.
Bead - CORRECT ANSWER-A rounded globule of re-solidified metal at the end of
the remains of an electrical conductor that was caused by arcing and is
characterized by a sharp line of demarcation between the melted and unmelted
conductor surfaces.
Blast Pressure Front - CORRECT ANSWER-The expanding leading edge of an
explosion reaction that separates a major difference in pressure between normal
