Question

17. There are following zones of a
flame
Two
O Three
O
Four
O
None​

Answer 1

Answer:

There are three different zones of a flame - dark zone, luminous zone and non-luminous zone.

Answer 2

There are four zones of flame :
1) outermost non-luminous zone of complete combustion
2) central luminous zone of incomplete combustion
3) inner dark zone of no combustion
4) lowest blue zone

SEE IN THE PICTURE GIVEN BELOW :-