Multiple choice

Why do Goldsmiths use the outermost zone of a flame with metallic blow pipe for melting gold and silver?

  1. It has unburnt carbon particles.

  2. Oxygen supply is less in this zone.

  3. It is the hottest zone.

  4. It has vapours which help in melting gold and silver.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The outermost zone is the hottest zone of the flame as oxygen is available in sufficient supply and complete combustion takes place here.

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