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8th Class Science Combustion and Flame Question Bank Combustion and Flame Conceptive Objective Problems

  • question_answer
    Goldsmiths blow the outermost zone of flame with a blow-pipe for melting gold and silver. Why do they use the outermost zone?

    A)  It is the zone of incomplete combustion and is least hot.

    B)  It is the zone of complete combustion and is the hottest zone.

    C)  It is the least hot zone and complete combustion takes place in this zone.

    D)  It is the hottest zone though incomplete combustion takes place in this zone.

    Correct Answer: B

    Solution :

      The outermost zone of a candle, which is also known as the non-luminous zone, is the zone of complete combustion. It is also the hottest part of the candle flame. Hence, it is used by goldsmiths to heat and melt gold. The correct answer is B.


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