IFSTA 10th Edition Test 4 Exam With Best Solutions

IFSTA 10th Edition Test 4 Exam With Best Solutions What occurs when a mixture of fuel and oxygen encounter an external heat source with sufficient heat or thermal energy to start the combustion reaction? (120) [4.3.11] A. Autoignition B. Piloted ignition C. Kinetic ignition D. Sustained ignition - Answer B. Piloted ignition The minimum temperature at which a fuel in the air must be heated in order to start selfsustained combustion is known as the: (122) [4.3.11] A. autoignition temperature (AIT). B. piloted ignition temperature (PIT). C. lower explosive (flammable) limit (LEL). D. upper explosive (flammable) limit (UEL). - Answer A. autoignition temperature (AIT). What causes flaming combustion to occur? (123) [4.3.11] A. A solid fuel encounters an open flame and entrain enough air to ignite. B. A gaseous fuel encounters an external heat source and experience piloted ignition. C. A gaseous fuel mixes with an adequate amount of oxygen and heats to ignition temperature. D. A solid fuel mixes with an adequate amount of liquid fuel to be able to sustain an open burning flame. - Answer C. A gaseous fuel mixes with an adequate amount of oxygen and heats to ignition temperature. What is the cause of most fire deaths? (124) [4.3.10, 4.3.11] A. Injuries caused by falling materials or structural collapse B. Exposure to toxic gases found in smoke and/or lack of oxygen C. Exposure to extreme heat and/or contact with flames and hot surfaces D. Accidental injuries sustained during escape and/or evacuation procedures - Answer B. Exposure to toxic gases found in smoke and/or lack of oxygen Fires involve a heat-producing chemical reaction between fuel and: (117) [4.3.11] A. a catalyst. B. an oxidizer. C. free radicals. D. a reducing agent. - Answer B. an oxidizer When a substance changes from one type of matter into another, such as two or more substances combining to form compounds, the substance undergoes a: (118) [4.3.11] A. dissolution. B. metamorphosis. C. chemical reaction. D. physiological change. - Answer C. chemical reaction Which statement about energy and combustion is accurate? (120) [4.3.11] A. A fuel's chemical energy is the result of rapid vibrations in the molecules. B. Chemical and physical changes almost never involve an exchange of energy. C. A fuel's potential energy releases during combustion and converts to kinetic energy. D. Chemical changes involve an exchange of energy; physical changes involve no energy exchange. - Answer C. A fuel's potential energy releases during combustion and converts to kinetic energy. Which element of the fire tetrahedron is included to explain flaming (gas-phase) combustion? (120) [4.3.11] A. Fuel B. Heat C. Oxygen D. Chemical chain reaction - Answer D. Chemical chain reaction Which statement about the dangers of products of combustion is accurate? (124) [4.3.11] A. Visible smoke presents the greatest inhalation danger. B. Low oxygen concentrations alone can result in hypoxia