CFEI Study Guide Questions With Correct Answers

The scientific method - Answer Recognize the need, define the problem, collect data, analyze the data, develop hypothesis, test hypothesis, select final hypothesis Fire effects are the result of? - Answer Exposure to fire Fire effects are part of what portion of the scientific method - Answer Data collection What are the general categories of fire effects? - Answer Discoloration, deformation, deposition, mass loss Fire Effect - Answer The observable or measurable changes in or on a material as a result of a fire Fire Analysis - Answer The process of determining the origin, cause, development, responsibility, and when required, failure analysis of a fire or explosion Fire Dynamics - Answer The detailed study of how chemistry, Fire science, and the engineering disciplines of fluid mechanics and heat transfer interact to influence fire behavior Fire Investigation - Answer The process of determining the origin, cause, and development of a fire or explosion Job Performance Requirements - Answer A statement that describes a specific job task, list the items necessary to to complete the task, and defines measurable or observable outcomes and evaluation areas for the specific task What aspects are involved in finding a cause? - Answer Circumstances, conditions, or agencies that brought the ignition source, fuel, and oxidant together Empirical Data - Answer Observation or experience and is capable of being verified or known to be true Deductive reasoning - Answer The process by which conclusions are drawn by logical inference from given premises. Comparing hypothesis to collected data Inductive Reasoning - Answer Starts from a particular experience and proceeds to generalizations. Develops hypothesis based on facts, training, expertise, experience, and knowledge Expectation Bias - Answer The use of only the data that supports this previously formed conclusion and often results in the misinterpretation and/or the discarding of data that does not support the original opinion Confirmation bias - Answer Confirming data that supports your hypothesis What are the two levels of certainty for an expert - Answer Probable and possible What level of certainty does not qualify for an expert opinion - Answer Suspected Probable - Answer Greater than 50% certainty Possible - Answer Feasible but not, less than 50% sure. If two hypothesis are likely then certainty has to be possible Fire - Answer A rapid oxidation process, which is an exothermic reaction, resulting in the release of heat and light energy in varying intensities. Energy - Answer A property of matter that manifests as an ability to perform work, either by moving over a distance against a force or by transferring heat. Calorie - Answer The amount of energy required to raise the temperature of 1 g of water by 1 degree Celsius BTU - Answer The quantity of heat required to raise the temp. Of 1 lb of water by 1 degree F at a pressure of 1 atmosphere and temp of 60 degrees F Energy is measured in.... - Answer Calories, BTUs, Joules Power - Answer Energy released per unit of time Power is measured in... - Answer Joules per second (J/s) or watts (W) Heat flux - Answer The amount of power per unit area Heat flux is measured in.... - Answer kW/m^2 or W/cm^2 Fire tetrahedron - Answer Fuel, the oxidizing agent, the heat, uninhibited chemical chain reaction Fuel - Answer Any substance that can undergo combustion Two common inorganic metals - Answer Magnesium and sodium Inorganic - Answer Does not contain carbon Organic - Answer Contains carbon Chemical oxidizers - Answer Ammonium nitrate fertilizer (NH4NO3), potassium nitrate (KNO3), hydrogen peroxide (H2O2) Gases that can form flammable mixtures in atmospheres other than oxygen or air - Answer Hydrogen and chlorine gas Stoichiometric Ratio - Answer Air is equal to fuel Phase changes - Answer No chemical reaction Thermal decomposition - Answer Irreversible changes in the chemical structure of a material due to the effects of heat (pyrolysis) Examples of premixed fuel and air - Answer Natural gas release and gasoline Premixed flame spread can present as... - Answer Deflagration or detonation Combustion explosion - Answer Premixed flame propagation in a confined volume Insufficient fuel mixture to reach the LEL is said to be... - Answer Too lean Insufficient oxygen molecule mixture to stay within UEL is said to be.... - Answer Too rich What relation between the LEL and UEL makes a fuel have a higher fire hazard - Answer The lower the LEL and the higher the UEL the wider the flammability/explosive range LOI - Answer Limiting oxygen index For most fuel vapors the LOI is in the range of... - Answer 10-14% by volume at ordinary temps Carbon dioxide and water is produced when... - Answer Complete combustion of hydrocarbon fuels containing only hydrogen and carbon Nitrogen oxide or hydrogen cyanide is produced when... - Answer Materials containing nitrogen such as silk, wool, and polyurethane foam Woot and tarry products accumulate on... - Answer Surfaces that remain the coolest longest Temperature - Answer A measure that expresses the degree of molecular activity of a material compared to a reference point Heat - Answer The energy needed to change the temperature of an object k Heat transfer is accomplished by what three mechanisms - Answer Condition, convection, and radiation Thermal conductivity - Answer A measure of the amount of heat per unit of time that will flow across a unit area with a temp gradient of 1 degree per unit of length Steady State Thermal Condition - Answer When temps are all interior points have stopped increasing During steady state heat transfer what is the dominant heat transfer property - Answer Thermal conductivity Products used to determine thermal inertia - Answer Thermal conductivity, density, and heat capacity Thermal inertia - Answer A measure of how easily the surface temp of the material will increase when heat flows into the material High density, high conductivity, and high thermal inertia means what type of surface temp change? - Answer Slow surface temp increase Thermal inertia is most important during which stages of a fire - Answer Initiation and early stages of a fire Thermal inertia determines what - Answer How fast the surface temp will rise