Chapter 6
COMBUSTION AND FLAME
1. List conditions under which combustion can take place
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2. Fill in the blanks.
(a) Burning of wood and coal causes ______ of air.
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(b) A liquid fuel, used in homes is ________.
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(C) Fuel must be heated to its ______ ________ before it starts burning.
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(d) Fire produced by oil cannot be controlled by _______.
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3. Explain how the use of CNG in automobiles has reduced pollution in our cities.
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4. Compare LPG and wood as fuels.
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5. Give reasons.
(a) Water is not used to control fires involving electrical equipment.
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(b) LPG is a better domestic fuel than wood.
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(c) Paper by itself catches fire easily whereas a price of paper wrapped around an aluminium pipe does not.
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6. Make a labelled diagram of a candle flame.
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8. Explain how CO2 is able to control fires.
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9. It is difficult to burn a heap of green leaves catch fire easily.
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10. Which zone of a flame does a goldsmith use for melting gold and silver and why?
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11. In an experiment 4.5 kg of a fuel was completely burnt. The heat produced was measured to be 180.000 kJ. Calculate the calorific value of the fuel.
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12. Can the process of rusting be called combustion? Discuss.
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13. Abida and Ramesh were doing an experiment in which water was to be heated in a beaker near the wick in the yellow part of the candle flame. Ramesh kept the beaker in the outermost part of the flame. Whose water will get heated in a shorter time?
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Type- Ankur Moni Nath
Post ID : DABP004823
