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प्रश्न
Write True/False against the following statement and also correct the false statement.
The substances which vapourise during burning, give flame.
विकल्प
True
False
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उत्तर
This statement is True.
Correct Statement:
The substances that vaporise during burning produce flames. When a fuel is heated, it undergoes vaporization and the vapours mix with oxygen in the air to combust, producing a flame. This is why liquid fuels like petrol, kerosene and alcohol give off flames when they burn, as they vaporise before combustion.
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संबंधित प्रश्न
Make a labelled diagram of a candle flame.
Name the unit in which the calorific value of a fuel is expressed?
If 4.5kg of fuel is completely burnt and amount of heat produced stands measured at 1, 80,000 KJ what is the calorific value.
The substances which gave very ______ ignition temperature and can easily catch fire with a flame are called ______ substances.
Anu wants to boil water quickly in a test tube. On observing the different zones of the flame, she is not able to decide which zone of the flame will be best for boiling water quickly. Help her in this activity.
Match the following for the flame of a candle.
| Column A |
Column B |
Column C |
| (a) hottest part | (i) innermost zone of unburnt wax vapours | (x) blue |
| (b) moderately hot | (ii) middle zone of partial combustion | (y) black |
| (c) least hot | (iii) outer zone of complete combustion | (z) yellow |
Write True/False against the following statement and also correct the false statement.
Middle zone is the hottest zone of a flame.
Name a few substances which produce flames on burning.
Explain the structure of a candle flame.
Why is the candle flame straight?
