NFPA 921 Definitions Exam Latest Updated

Absolute Temperature. - ANSWER-A temperature measured in Kelvins (K) or Rankines (R). Accelerant. - 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. - 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. Ambient. - ANSWER-Someone's or something's surroundings, especially as they pertain to the local environment; for example, ambient air and ambient temperature. Ampacity. - ANSWER-The maximum current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its temperature rating. [70, Article 100] Ampere. - 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. - ANSWER-A high-temperature luminous electric discharge across a gap or through a medium such as charred insulation. Arc Mapping. - 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. - ANSWER-The location on a conductor with localized damage that resulted from an electrical arc. Arcing Through Char. - ANSWER-Arcing associated with a matrix of charred material (e.g., charred conductor insulation) that acts as a semiconductive medium. Area of Origin. - ANSWER-A structure, part of a structure, or general geographic location within a fire scene, in which the