Question

Incandescent region in candle flame is. .
A. Non luminous
B. Luminous
C. Dark zone
D. None of these

Answer 1

Answer: The correct option is B.

Explanation: Incandescent means that emits light as a result of heating.

Candle flame consists of 3 zones:

• Outer zone: This zone is blue in color because here complete combustion takes place. This is the hottest zone of the candle. It is non-luminous zone of the candle.

• Middle zone: This zone is bright yellow in color because here, partial combustion takes place. This is the bright part of the flame because the fuel particles burn and produces carbon particles which becomes white when hot. This is the luminous zone of the candle.

• Innermost zone: This zone is black in color due to the unburnt wax vapors.

Luminous zone only contributes to the incandescent region of the candle.

Answer 2

In a candle flame, several zones can be seen with the eye.

At the bottom, there is a region giving off blue light.

Reason: Molecular emission from gaseous carbon.

This is known as the "incandescent region" where particles glow and give off light like the filament of a light bulb.

Luminescence: The emission of light by a substance in fluorescence and phosphorescence is called Luminescence.

Hence, Incandescent region in candle flame is luminous.

The answer is (B) Luminous.