Combustion and Flame - Chapter Wise CBSE Solved Question and Answer Based On NCERT
Very Short Q&A:
Q1: Give example of some of the fuel used in our day to day life.
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Cow dung, coal, wood, petrol, charcoal, compressed natural gas (CNG)
Q2: Define combustion
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The chemical process in which a substance reacts with oxygen to give off heat is called combustion.
Q3: Define combustible
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The substance which undergoes combustion is called combustible or fuel.
Q4: The fuel may be solid , liquid or _______________
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Gas
Q5: Which of the following is not a combustible substance
Wood
Petrol
Nail
All of them
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Nail
Q6: Sometimes light is also given out during ______________
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Combustion
Q7: Air is required for combustion or not?
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Yes
Q8: Which fuels are used for running automobiles?
Wood
Coal
Diesel
Charcoal
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Diesel
Q9: Combustion is a reaction in which a Substance reacts with
Hydrogen
Nitrogen
Oxygen
Chlorine
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Oxygen
Q10: What is ignition temperature?
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The lowest temperature at which a substance catches fire is called its ignition temperature.
Q11: Different substances catch fire at different ________________________
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Temperature
Q12: Can a matchstick catch fire on its own on room temperature?
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No
Q13: Name the substances by which head of the matchsticks are made of?
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Antimony trisulphide and potassium chlorate
Q14: Name the substances by which the rubbing surface of matchsticks are made of?
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Powdered glass and a little red phosphorous
Q15: A combustible substance cannot catch fire or burn as long as its temperature is lower than its ______________________.
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Ignition temperature
Q16: What do you mean by inflammable substances?
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Certain substances have very low ignition temperature and can easily catch fire with a flame are called inflammable substances like petrol, LPG etc.
Q17: Give examples of inflammable substances.
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Alcohol, petrol, LPG etc.
Q18: List the three essential requirements for producing fire.
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Fuel, air and heat
Q19: The job of fire extinguisher is to cut of the supply of______________________.
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Air
Q20: Which of the following are inflammable Substances?
Petrol
Wood
Paper
Straw
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Petrol
Q21: Give example of rapid combustion.
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Bring a burning matchstick or gas lighter near a gas stove and turn on the knob of gas stove, we will find the gas burns rapidly and produces heat and light, this is an example of rapid combustion.
Q22: Cracker is example of__________________________ combustion.
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Explosion
Q23: Which is the hottest part of a flame?
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Outer zone of complete combustion
Q24: Good fuel is which is
Cheap
readily available
produces large amount of heat
All of these
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All of these
Q25: Give examples of some gaseous fuel.
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Liquefied petroleum gas (LPG)
Q26: Which of these fuels will produce large amount of heat LPG, coal or wood?
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LPG
Q27: The unit of calorific value is ____________________.
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Kilojoule per Kg
Q28: Incomplete combustion of these fuels releases __________________________ gas.
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Carbon mono oxide
Q29: What is acid rain?
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Sulphur and nitrogen oxides present in atmosphere dissolves in rain water and forms acids, such rain is called acid rain.
Q30: What is calorific value?
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Calorific value of the fuel is the amount of heat energy produced on complete combustion of 1 kg of fuel; it is expressed in kilojoule per kg
Q31: Fire produced by oil cannot be controlled by________________________.
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Water
Q32: When a cracker is ignited a sudden reaction takes place with the evolution of heat, light and sound, this is an example of what type of combustion?
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Explosion
Q33: Fuel must be heated to its_________________ before it starts burning.
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Ignition temperature
Q34: Name a liquid fuel used in our home.
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Kerosene oil
Q35: Name the gases involved in acid rain.
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Gases involved in acid rain are sulphurdioxide and nitrogen dioxide
Q36: Name the modern fuel replacing diesel and petrol in automobiles
