True or False 19. If you are on a personal connection, like at home, you can run an anti-virus scan on your device to make sure it is not infected with malware. Question. 45000 kJ/kg 35000 to 40000 kJ/kg 45000 kJ/kg. In jar B, the candle remains lighted for a longer time because oxygen is a supporter of combustion. Question. 9. Question. Explain. (e) The substances which have very low……………… temperature and can easily catch fire with a flame are called…………….. substances. They can also be used on small class B (liquid) fires, but cooling effects on the liquid are limited and the fire may re-ignite after it has been extinguished. If you attempt to fight a small fire with a fire extinguisher, it is important to: a. Some of the non-combustible substances are stone, glass, cement, soil, sand, iron nails, etc. 16 Fill in the blanks. Your First Line of Defence. p. 270 11.40. Kerosene is used in stoves to cook food and in lamps and petrol is used as a fuel in automobiles. In such situations, soda-acid fire extinguisher does not work as it contains water or uses water to take off fire by cooling down the place. Class A, B and C . Carbon Dioxide extinguishers are filled with non-flammable carbon dioxide gas under extreme pressure. (10) 12 In villages, people use wood as fuel because Kerosene, petrol and alcohol have low ignition temperature. When an extinguishing agent covers and cools the fire source, the fire loses its: a. Asked by Wiki User. Answer. industries, CNG is used to run automobiles. The cooking oil all of a sudden caught fire, he poured water to extinguish the fire. CO2s may be ineffective at extinguishing Class A fires because they may not be able to displace enough oxygen to successfully put the fire out. Question. Since, the contact between the fuel and oxygen is cut off, so the fire can be controlled. This 5-pound extinguisher has an aluminum bottle, making it lightweight and easy to carry. Will it produce a flame? (c) Carbon dioxide is an excellent fire extinguisher. Classes of Fire Definitions: Green = Suitable; Red = Not Suitable; Orange = Limited Why? But sand or soil will not be available at that place. (c) Due to incomplete combustion of fuel, copper vessel was getting blackened from outside. • (c) cover the person with a woollen blanket 13 Which one among the following is considered as the cleanest fuel? One to two minutes. (c) LPG has the highest calorific value, i.e. Since, the contact between the fuel and oxygen is cut off, so the fire can be controlled. (5) Only energy and clean water are produced. Carbon Dioxide. Across (b) Wood, paper, CNG are ……………substances. A. CO2 extinguishers are … Question. Answer. Fire happens when three things are in the same place at the same time: ... A foam extinguisher, on the other hand, works a bit more like a carbon dioxide extinguisher when the nozzle is open: the water and foaming solution swirl together in the nozzle, producing a much bigger volume of foam than the volume of the can itself. So, we can say that oxygen (air) is necessary for combustion to take place. Class A fire extinguishers can be used on electrical fires False ( Class C) While using a fire extinguisher hold the extinguisher firmly and direct it to the middle or main part of the fire 19 Anu wants to boil water quickly in a test tube. 4. What is most likely to kill you in a fire? C02 being heavier than oxygen, covers the fire like a blanket. (ii) Camp fire may also be a reason. It will not produce a flame. Carbon dioxide fire extinguishers should be sited 10m from a recognised hazard if being used for Class B fires, and close to the electrical equipment they are expected to protect if used for electrical hazards. Class B … Answer. The oil floats on water and continues to burn. (c) Carbon dioxide is an excellent fire extinguisher. 2. Your IP: 148.251.76.241 When used for Class B and C fires, the CO 2 covers the fuel by blanketing it, and stops the reaction at the surface by displacing oxygen. (b) Slaas is a non-combustible material. Answer. CO 2, being heavier than oxygen, covers the fire like a blanket. Q. (d) cover the person with a polythene sheet A comprehensive database of more than 15 fire extinguisher quizzes online, test your knowledge with fire extinguisher quiz questions. The new standard is BS EN3 part 5, and an extinguisher is Signal Red with a band of colour above the instructions to signify the use of the extinguisher. Answer. CO2s will frequently be found in laboratories, mechanical rooms, kitchens, and flammable liquid storage areas. We will prefer CNG (Compressed Natural Gas) because the calorific value of CNG is higher than that of petrol. (i) Air is necessary for combustion. 18 Two glass jars A and B ajre filled with carbon dioxide and oxygen gases respectively. Note Find an answer to your question carbon dioxide is storedIn a fire extinguisher as a liquid in cylinder at low pressure. These are used to cook food in homes. So, in the incomplete supply of oxygen, coal burns to produce carbon monoxide which is highly poisonous gas. Answer. Class A materials may also smolder and re-ignite. Smoke detectors are not used in cargo and baggage compartments. Monoammonium phosphate effectively smothers the fire, while sodium bicarbonate induces a chemical reaction which extinguishes the fire. Since CO2 extinguishers are perfect for electrical fires, they are commonly found in offices or places where there is a lot of electrical devices. According to the NFPA, some of the types of hazards and equipment that carbon dioxide systems protect are "flammable liquid materials; electrical hazards, such as transformers, switches, circuit breakers, rotating equipment, and electronic equipment; engines utilizing gasoline and … a. true b. false ref. (b) Magnesium is a non-combustible metal. (a) Air is necessary for combustion. (a) throw water on the clothes is called combustion. 35 The calorific values of petrol and CNG are 45000 kJ/kg and 50000 kJ/kg respectively. (a) Air is necessary for combustion. Also write the false statements in their correct form. What Are the Types of Portable Fire Extinguisher? (a) Air is necessary for combustion. True or False 17. 2.Non-combustible — chalk, stone, iron rod, copper coin, glass. Question. cor. 20 Why is the use of diesel and petrol as fuels in automobiles being replaced by Compressed Natural Gas (CNG) in big cities? (a)A ……….. process in which a substance reacts with ……….. to give off heat (b) When the clothes of a person catch …………the person is covered with a…………… to extinguish fire. Answer. Note The lowest temperature at which a substance catches fire and starts burning, is called its ignition temperature. CO2 is clean, non-corrosive and leaves no residue on expensive computers and electronic equipment. a. true b. false ref. Reasons of forest fires are : The carbon dioxide extinguisher pushes oxygen away from the fire and replaces it with carbon dioxide, which is inflammable and more dense than air. The fire dies when the oxygen and fuel can no longer interact due to the chemicals introduced by a dry chemical extinguisher. 55000 kJ/kg. (d) The substances which gave very …………..ignition temperature and can easily catch fire with a flame are called………….substances. Question. c. Use the. Question. Charcoal, chalk, stone, iron rod, copper coin, straw, cardboard, glass, paper, candle, wood. Answer.Across 11. 26 Fill in the blanks using the words given in the box. The other one is called a propellant and is a pressurized chemical that makes the fire-fighting substance come out when you press the extinguisher handle. Water (iv) The use of fires by villagers to ward off wild animals. Answer. The Kidde Pro 5 is a great choice if you’re looking for a reliable carbon dioxide fire extinguisher. Carbon dioxide continues to be used in numerous applications around the world for the extinguishment of flammable liquid fires, gas fires, electrically energized fires and, to a lesser degree, fires involving ordinary cellulosic materials such as paper and cloth. (d) low, inflammable Performance & security by Cloudflare, Please complete the security check to access. The best extinguisher for carbon dioxide is an excellent fire extinguisher true or false involving electrical equipment a blanket frying pan unit... 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