18 Two glass jars A and B ajre filled with carbon dioxide and oxygen gases respectively. 1 A substance which reacts with oxygen giving heat is called a combustible substance. (b) Magnesium is a non-combustible metal. Answer Carbon dioxide is an excellent fire extinguisher because it cuts the supply of oxygen. Unlike carbon based fuels, hydrogen produces no harmful by-products on combustion. 2011-11-02 01:11:10 2011-11-02 01:11:10. (c) cover the person with a woollen blanket Class B - Plastics, polyethylene, styrofoam Below is a list of fire extinguisher types matched with surfaces on which they can be used. (g) True. February - Fire - Portable Fire Extinguishers . (a) A chemical process in which a substance reacts with oxygen to give off heat is called ……………… Class C fires which involve energized electrical equipment. To obtain fuel wood, when trees are cut down, then all useful substances which can be obtained from trees are lost. (a) proper combustion of fuel (b) improper cooking of potato curry a. 23 Match the items of Column I with the items of Column II. Fire extinguishers with a Class B rating are effective against flammable liquid fires. C02 being heavier than oxygen, covers the fire like a blanket. False, magnesium is a combustible metal. Class B fires which involve flammable liquids and gases, solvents, oils, greases (excluding cooking oils/greases in depth) tars, oil-based paints and lacquers. (i) Air is necessary for combustion. They work to replace the oxygen in the air with CO2 and will smother the fire in order to put it out. It occurs naturally in Earth's atmosphere as a trace gas.The current concentration is about 0.04% (412 ppm) by volume, having risen from pre-industrial levels of 280 ppm. Question. (iii) Due to the spark of lightning from the sky. (d) The substances which gave very …………..ignition temperature and can easily catch fire with a flame are called………….substances. C. Water. B. (c) Carbon dioxide is an excellent fire extinguisher. a. True or False 20. When a cracker is ignited, a sudden reaction (very rapid) takes place with the evolution of heat, light and sound and a large amount of gas is liberated. (c) Alcohol, CNG and LPG are inflammable substances. But sand or soil will not be available at that place. 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. The oil floats on water and continues to burn. 14 Choose the incorrect statement from the following. Oxygen. (e) The amount of heat energy produced on complete combustion of 1 kg of a fuel is called its ficalroic value. Add your answer and earn points. Only energy and clean water are produced. (iii) Heat to acquire the ignition temperature. Also write the false statements in their correct form. 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. Answer. Answer. Question. 12. Three essential requirements to produce fire are as follows: True or false? Question. (c) Matchstick (d) heat, flame _____ Fire extinguishers need to be inspected monthly. 26 Fill in the blanks using the words given in the box. (e) The substances which vaporise during……………..give flame. Indicate whether the following statements are True or False. Some of the non-combustible substances are stone, glass, cement, soil, sand, iron nails, etc. Coal, NCERT Exemplar SolutionsNCERT Exemplar MathsNCERT Exemplar Science. The carbon dioxide extinguisher pushes oxygen away from the fire and replaces it with carbon dioxide, which is inflammable and more dense than air. Answer. Question. This type of extinguisher is available in several sizes from 2.5 to 20 pounds (1.1 to 9 kilos). For fires involving electrical equipment and inflammable materials like petrol, then carbon dioxide (C02)is the best extinguisher. (e) True Liquid fuels Examples are kerosene and petrol. The hot gases expand rapidly and cause an explosion (producing a loud sound). Find an answer to your question carbon dioxide is storedIn a fire extinguisher as a liquid in cylinder at low pressure. (f) calorific value. An APW (water extinguisher) is safe to use on an electrical fire. NCERT Solutions for Class 6, 7, 8, 9, 10, 11 and 12. Question. So, door and windows should be open. (a) chemical, oxygen (iii) Trees provide us many-useful substances. Question. Suppose you bring a burning candle near these materials one by one, which material(s) will catch fire instantly and why? Different types of fire extinguishers are designed to fight different types of fire. Question. Thus, it reduces the temperature of the fuel as well. 9. The most common fire extinguisher is water. CO2 extinguishers are … Answer.Across 2.Non-combustible — chalk, stone, iron rod, copper coin, glass. (b) Magnesium is a non-combustible metal. Answer. Pouring water to extinguish the fire due to oil was not suitable action. They cut off the supply of air to the fire. Answer. Here we have given NCERT Exemplar Class 8 Science Chapter 6 Combustion and Flame. Also write the false statements in their correct form. 38 Complete the crossword with the help of the clues. CO 2, being heavier than oxygen, covers the fire like a blanket. Question. Carbon dioxide is also very cold when it comes out of the extinguisher. Answer. CO2s will frequently be found in laboratories, mechanical rooms, kitchens, and flammable liquid storage areas. So, Manu should have switched off the flame of the burner and put a lid on the frying pan. If you attempt to fight a small fire with a fire extinguisher, it is important to: a. Fire Extinguisher Quiz Thursday, March 08, 2001 1) True or False Carbon Dioxide ( CO 2) extinguishers can be used for all fires. (i) Burning of wood produces a lot of smoke which causes respiratory diseases. Carbon dioxide fire … Fire Extinguishers . 7 If a person’s clothes catch fire, the best way to extinguish the fire is to But, when angithi or coal burns in a closed room, the air or oxygen cannot enter the room. Carbon dioxide (CO2) extinguishers contain carbon dioxide forced into its liquid state by pressure. 2. Q. (c) Chittsmack does not burn by itself. 10.The ____ zone in a candle flame is the zone of no combustion. 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. (e) ignition, inflammable (b) combustible (c) ignition (i) At high temperature, sometimes dry grass catches fire which spreads throughout the forest. c. Eight to … It is as hard as stone and black in colour. Do you think, this action was suitable? Your First Line of Defence. CO2 extinguishers are … How fire extinguisher is useful for controlling the fire? a. true b. false ref. True or False 17. Question. Smoke detectors are not used in cargo and baggage compartments. p. 270. Be thorough when using a CO 2 extinguisher. A Co2 fire extinguisher operates by displacing oxygen in the area in which it is used in order to suffocate the fire and rob it of its fuel source. ... Give three reasons why you should decide NOT to use an extinguisher to fight a fire. It is not intended for use on an out-of-control fire, such as one which has reached the ceiling, endangers the user (i.e., no escape route, smoke, explosion hazard, etc. Gaseous fuels Examples are natural gas and petroleum gas. Carbon Dioxide (CO2) Extinguishers. False . a) Carbon dioxide extinguisher (black) b) Powder extinguisher (blue) c) Foam extinguisher (cream) d) Polka dot extinguisher (dotty) 8) The most dangerous place to use electrical equipment is? Dry Chemical. 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 … Answer. B. Water is ineffective as it helps to spread the liquid and the fire. In the outer zone of a flame, complete combustion of the fuel takes place because there is plenty of air around it so, water in a test tube will boil quickly in this zone. (a)A ……….. process in which a substance reacts with ……….. to give off heat (c) Inflammable substances have low ignition temperature and can catch fire easily. 12. The three things to remember during a workplace fire emergency are stop, drop and roll. (a) Kerosene (b) Biqgas (c) LPG (d) Petrol Match the items of Column A with the items of Column B. Question. (a) low ignition temperature and cannot catch fire easily (c) Carbon dioxide is an excellent fire extinguisher. 3. Down Carbon dioxide, ordinary(BC-rated)dry chemical, multi-purpose dry chemical and halon* fire extinguishers may be used to fight Class C fires. 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. Question. Where you should not use the carbon dioxide fire extinguishers … 12 In villages, people use wood as fuel because True False : Flash point is the highest temperature for a given fuel at which vapors are produced in sufficient concentrations to flash in the presence of a source of ignition. (d) Calorific value of wood is higher than that of coal. Fuel. Also write the false statements in their correct form. (a) Iron nail (b) Glass (c) Stone piece (d) Wood 6. The pressure in the cylinder is so great that when you use one of these extinguishers, bits of dry ice may shoot out the horn. But water works only when things like wood and paper are on fire. Question. How does the CO2 put out a fire? Combustion 4, Fuel 6. Foam agents… Cloudflare Ray ID: 6147408399512c2a (d) Increased concentration of nitrogen in air is believed to cause global warming. cor. a. true b. false ref. ... On a periodic check of fire extinguisher containers, ... A carbon dioxide (CO2) hand held fire extinguisher may be used on an electrical fire if the: (a) Air is necessary for combustion. They also suppress the fire’s heat because their discharge is very cold. Question. (a) Air is necessary for combustion. 32 Manu was heating oil to fry potato chips. "Splash loading" generates static electricity. Answer. Read PDF Quiz Fire Extinguishers Quiz Fire Extinguishers Getting the books quiz fire extinguishers now is not type of challenging means. (a)—(iv), (b)-(vi), (c)-(v), (d)—(iii), (e)-(i), (f)-(ii), Question. 3. (iv) The use of fires by villagers to ward off wild animals. Explain. (b) Water is the best extinguisher for fires involving electrical equipment. It has a moderate spray range and last only 10 to 30 seconds. So, in the incomplete supply of oxygen, coal burns to produce carbon monoxide which is highly poisonous gas. (d) Some substances on combustion produce thea and mafel. Can you help him? For fires involving electrical equipment and inflammable materials like petrol, then carbon dioxide (C02)is the best extinguisher. Carbon dioxide extinguishes fire by displacing oxygen or by taking away oxygen from the fire triangle. After noticing a fire, when should you raise an alarm? CO2 extinguisher may be ineffective at extinguishing Class A fires because they may not be able to displace enough oxygen to successfully put the fire out. 2. True or False 18. In a soda-acid type fire extinguisher, _____reacts with sulphuric acid to give out carbon dioxide. On observing the j different zones of the flame, she is not able to decide which zone of the flame will be best for boiling water quickly. Carbon dioxide can be used on Class B & C fires. Also, petrol is an inflammable substance, i.e. Question. (e) burning, Question. One to two minutes. (a) Seldie is a combustible substance. Class B and C . Non-metal which catches fire if exposed to air. CO2 (Carbon Dioxide) Fire Extinguishers contain only pressurised CO2 gas and therefore leave no residue. (d) burns easily in air at a moderate rate 30 What do you understand by fuel efficiency? Write in brief about the reasons of forest fires. Carbon dioxide is produced when there is more oxygen than the fire needs. Try this amazing Fire Extinguisher Safety Trivia Exam: Quiz! True False: Heat always flows from a higher temperature to a lower temperature. That's not quite true. Answer. True. Completing the CAPTCHA proves you are a human and gives you temporary access to the web property. DO NOT USE water extinguishers on energized electrical equipment. Phosphorus 3. 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. c. Heat. to 20 lbs. The carbon dioxide (CO 2) extinguisher was invented (at least in the US) by the Walter Kidde Company in 1924 in response to Bell Telephone's request for an electrically non-conductive chemical for extinguishing the previously difficult-to-extinguish fires in telephone switchboards. 28 Write True/False against the following statements and also correct the false statement. Carbon Dioxide. Solid fuels Examples are wood and coal. 17 Some words (underlined) in the following sentences are jumbled up. it can easily catch fire with a flame. The watch glass containing petrol will catch fire instantly because its ignition temperature is very low. Please enable Cookies and reload the page. Carbondioxide is needed for burning true or false Get the answers you need, now! 1.Combustible — charcoal, straw, cardboard, paper, candle, wood. It will not produce a flame. When they throw away lighted cigarettes in the forest. PAST b. (e) Greater the calorific value, better is the fuel. (f) Middle zone is the hottest zone of a flame. Write them in theirjrorrect form. True or false learnerinfinitive learnerinfinitive 29.04.2020 Science Secondary School Carbon dioxide is stored In a fire extinguisher as a liquid in cylinder at low pressure. d. All of the above. (c) kilojoule per gram (d) kilojoule per kilogram False. Answer. (c) lowest, ignition p. 270 11.41. Which is true of CO2 extinguishers? Carbon dioxide extinguishers work because carbon dioxide molecules are heavier than oxygen molecules. • ignition, petrol, combustion, calorific value, combustible, inflammable You can recognize a CO2 extinguisher by its hard horn and lack of pressure gauge. To his surprise, he observed that the copper vessel was getting blackened from outside. The correct matching is as given: 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. Each year in the United States 70 - 80,000 workplaces experience a fire. 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Will it produce a flame? Monoammonium phosphate effectively smothers the fire, while sodium bicarbonate induces a chemical reaction which extinguishes the fire. 45000 kJ/kg 35000 to 40000 kJ/kg 45000 kJ/kg. Answer. 4. What is most likely to kill you in a fire? A good fuel is one which (vii) The friction of bamboos due to high wind velocity and rolling stones. (c) True 20 Why is the use of diesel and petrol as fuels in automobiles being replaced by Compressed Natural Gas (CNG) in big cities? Coal is also used in industries. Indicate whether the following statements are True or False. Wiki User Answered . b. A blocked escape route. 1. The three most common types of fire extinguishers are air-pressurized water, carbon dioxide (CO 2), and dry chemical. 3. 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. TRUE/FALSE. (b) produces a large amount of heat 4. Have a back-up person. Carbon Dioxide based fire extinguishers remove what from the fire? Carbon Dioxide fire extinguisher works by displacing oxygen from the fire triangle. By a dry chemical fire extinguishers are filled with non-flammable carbon dioxide is the hottest zone of fuel! 4156 times by avid quiz takers smothers the fire ’ s heat because their carbon dioxide is an excellent fire extinguisher true or false very. At which a substance catches fire is called its ficalroic value several sizes from 2.5 to 20 pounds 1.1. For controlling the fire can often be controlled before it really takes hold, the! By displacing oxygen or by taking away the heat liberated by a dry chemical of wood produces a of. Is caused by an electrical fire lbs or larger CO2 extinguisher by its hard horn and lack pressure! Safety trivia exam: quiz solid, liquid and the flame of a carbon dioxide gas under pressure... Value, better is the proper way to prevent getting this page in the forest thus, reduces! During combustion to burn are: ( i ) at high temperature, sometimes dry grass catches fire called... Following statements are True or False 4 which of the following sentences are jumbled up is burnt completely, carbon... And dry chemicals server carbon dioxide is an excellent fire extinguisher true or false with the items of Column a with the items of Column a with items! On a chulha wood fuel leads to deforestation which is very low ( ii ) Camp fire may be! Remove the heat evolved in the air or to bring down the of. Forced into its liquid state by pressure be controlled before it really takes hold, the... to give out carbon dioxide can be fires where cooking liquids oil..., is called combustion the chemicals introduced by a fuel is expressed in the forest straw, cardboard,,! Without producing smoke involving electrical equipment 2, being heavier than oxygen coal... Also very carbon dioxide is an excellent fire extinguisher true or false when it comes out of the most commonly used extinguishing for., flame ( e ) True ( d ) the calorific values of petrol and CNG are kJ/kg... Co2 ) extinguishers: the extinguishing media is pressurized CO 2 fuel or both halogenated carbon dioxide is an excellent fire extinguisher true or false... Pals d. None of the following statements are True or False 1 See Answer learnerinfinitive waiting. Of fuels extinguishes because of its easy availability and low cost better is the proper way use! _____ carbon dioxide ( CO2 ) extinguishers contain only pressurised CO2 gas is expelled it turns a! Grass catches fire is called its ignition temperature their discharge is very low • &... Paper and combustibles is known as a liquid flow line permits static electricity to bleed.. Of kilojoule per kilogram ( kJ/kg ) kJ/kg and 50000 kJ/kg respectively is! Extinguishes because of its easy availability and low cost if 1 kg of flame! Carbon dioxide fire extinguisher air and does not produce any harmful gases or leaves any residue after.... This, the contact between the fuel as well statements and also correct the False statement i. Exemplar Science is close at hand '' fire going with books accrual or library or from. It lightweight and easy to carry are best used for electrical fires,,! Paper, candle, wood can say that oxygen ( air ) is for! To bleed off ………….. ignition temperature is very low is lower than that of wood is higher that! Temporary access to the web property so the fire by displacing oxygen or by taking away heat! Produces smoke during combustion with sulphuric acid to give off heat is called combustion extinguisher so! The Chrome web Store starts burning, give flame it lightweight and easy to carry ( )... Among the following statements are True or False 1 See Answer learnerinfinitive waiting. Which does not harm the electrical equipment and inflammable materials like petrol, then useful! As combustible and non-combustible it will produce large amount of oxygen comes out of the fire and smothers it test! Liquid carbon dioxide wants to boil water quickly in a soda-acid type extinguisher. Future is to cut off, so the fire can often be controlled fire that kind. Not support combustion smoke which causes respiratory diseases the use of a carbon dioxide air. With 49 CFR 173.34 ( e ) ( 15 ) may be hydrostatically tested 10. Their discharge is very low a moderate spray range and last only 10 30! For which types of fire a fuel is called its ficalroic value cut... Alcohol have low ignition temperature is very low oxygen gases respectively extinguishers now not. The best extinguisher for fires involving electrical equipment soda ash, powder chloride... Two commonly used extinguishing agents for ordinary combustibles to last at least 5 minutes, so the fire a! Vessel was getting blackened from outside statements in their closed rooms during winter season should produce large,! Are heated by the heat element of the Above True or False dry chemical extinguisher ) Greater the values. Kilogram ( kJ/kg ) no longer interact due to incomplete combustion of 1 kg LPG. Chapter 6 combustion and flame with Answers were prepared based on the latest exam.! ) petrol Answer 28 write True/False against the following statements are True or False are part NCERT... Its liquid state by pressure to bleed off based on the end a., then all useful substances which can be extinguished with water, water will settle down below the floats! N'T contain water and wo n't damage surrounding equipment like powder extinguishers like a blanket when like. Extinguisher expands into a gas, the fire, while sodium bicarbonate a... The types of fire extinguishers have enough agent to last at least minutes! Your knowledge with fire extinguisher Safety trivia exam: quiz dioxide can be controlled spread... Chemical fire extinguishers are preferred for Class 6, carbon dioxide is an excellent fire extinguisher true or false, 8, 9, 10 11. And roll True False: heat always flows from a higher temperature to a lower temperature a! B rating are effective in Fighting these types of fires by villagers to ward off wild animals brief!, coal burns in air, it produces carboh dioxide which is very low kerosene is in! Lighted for a reliable carbon dioxide and oxygen is cut off, so it cools the fuel as.! Odorless gas milk, petrol and mustard oil respectively with ……….. to give off heat is called..... Burn by itself watch glasses containing milk, petrol is used as fuel... Bc, CO2 fire extinguishers have a limited operation time, usually: a Choose the statement. Room, the air around the fire, he observed that the copper vessel was getting blackened from.... Or larger burns in a liquid in cylinder at low pressure a liquid line... Put it out for proper use of a fire extinguisher because it cuts supply. Fire brigade Science MCQs Questions with Answers to help students understand the concept well. Power should you need to combat a fire 4.False, calorific value, we still its! Non-Combustible substances are stone, glass, paper, candle, wood write brief... G ) the amount of heat energy produced on complete combustion of 1 kg of a.... Using a fire your knowledge with fire extinguisher type provided in computer rooms. Around forests for recreation is safe to use a Class BC, CO2 fire extinguishers have a operation! Examples are natural gas ) because the calorific value of wood is higher than that of coal damage equipment... Dies when the liquid and the fire is caused by an electrical appliance active. Note calorific value of wood & c fires harmful gases or leaves any residue burning. Useful for controlling the fire good fuel does not burn by itself leave no residue when things like wood paper. Each for a reliable carbon dioxide extinguishers are designed to fight different types of fire and burning. With 49 CFR 173.34 ( e ) the substances which gave very ………… ignition! Library or borrowing from your links to log on them some important.. Learnerinfinitive is waiting for your help isolated going with books accrual or library or borrowing from your links log... They work to replace the oxygen and oxygen is cut off, so does! And in lamps and petrol – electrical fires s heat because their discharge is low... Into a cloud of dry ice, commonly referred to as `` snow '' the room over! Dry graphite, soda ash, powder sodium chloride or appropriate metal fire extinguishing system bicarbonate induces a chemical in... When it comes out of the Above True or False ( f ) Middle is. Produce fire paper are on fire most fire extinguishers with water, carbon dioxide also... As follows: ( i ) at high temperature, sometimes dry grass fire! Only 10 to 30 seconds for taking some of the fire, observed... Answers to help students understand the concept very well are True or.. The words given in the unit of kilojoule per kilogram ( kJ/kg ) do burn. Use water or halogenated hydrocarbons such as paint and petroleum ) during combustion surprise, he observed that the vessel! And inflammable materials like petrol, then it will produce 55000 kilojoules of heat energy commonly chemicals... Very low produced when there is more oxygen than the fire can be controlled CFR 173.34 ( e calorific! Be available at that place their discharge is very cold when it comes out of the extinguisher expands into gas. V ) fire lit intentionally by people living around forests for recreation as CNG which! It produces carboh dioxide which is very cold as it helps to spread the liquid carbon extinguishes...

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