Question

Anu wants to boil water quickly in a test tube. On observing thedifferent zones of the flame, she is not able to decide which zoneof the flame will be best for boiling water quickly. Help her inthis activity.NCERT Class VIIIScience - Exemplar ProblemsChapter 6. Combustion and Flame

Answer 1

It is unaware to many that there are different zones in a flame.

The outermost part of the flame is the non-luminous part of the flame and is generally blue in color which is mainly due to the complete combustion.

This will be the best part for Anu to quickly heat the test tube.

Answer 2

$\textbf{Outer Most Zone}$

Actually the most hottest zone of a flame is its outer most zone.

This zone is faintly visible and surrounds the yellow luminous part of the flame.