Question

Which zone in a candle flame gives out the maximum light?
(a) dark zone
(b) non-luminous zone
(c) blue zone
(d) luminous zone

Answer 1

(d) luminous zone

The luminous zone of a candle flame is the zone of incomplete combustion. The wax vapours do not burn completely, since the supply of oxygen is inadequate in this zone. When an object is placed over this zone, it releases black soot and other residues. The carbon particles in it, glow, emitting a yellow light.