Question

There are three different zones of candle flame A, B and C as shown in figure. Which one of the following is correct?

A.B is the hottest part of flame
B.C is moderately hot
C.A is the hottest part of flame
D.A is moderately hot whereas C is the coldest part

Answer 1

Hint:
There are three zones in the candle flame in which the non – luminous zone is the zone of complete combustion, the luminous zone has limited oxygen supply and is moderately hot and the third zone is the dark zone which does not burn due to the absence of air.

Complete step by step answer:
The area of combustion of combustible substances is called flame. It can be produced during burning. The substance which vaporizes produces the flame.
The candle flame has three zones which have different roles. All the zones of the candle flame have different colours and different temperatures. The three zones of a flame are:
Non – Luminous Zone: This zone is the zone of complete combustion. It has sufficient supply of air due to which complete combustion of fuel takes place. This is the outermost zone of the flame and is the hottest of all the zones. It poses the highest temperature among all the zones. It is quite thin as compared to the middle zone. The colour of this zone is blue.
Luminous zone: Luminous zone is bright and is the middle zone of candle flame. The temperature in this zone is moderate hot. It does not have a sufficient supply of oxygen. The colour of this zone is yellow.
Dark Zone: The temperature of this zone is least hot. It is black in colour. This zone does not support burning due to no supply of air.
According to the question, zone A is the non – luminous zone, B is the luminous zone and C is the dark zone of the flame because as shown in figure, A is at outermost, B is in the middle and C is the innermost zone.
Therefore, option C is the correct answer.

Note:
The innermost zone of candle flame is called the dark zone of the flame. The middle zone of the flame is the luminous zone of the candle flame and the non – luminous zone is the outermost and hottest of all zones in the candle flame.