Question

while cooking, if the bottom of the vessel is getting blackened on the outside, what does it means ?

1. the food is cooked completely
2. the fuel is not burning completely
3. the fuel is wet
4. the fuel is burning completely

please tell me I am very confuse.​

Answer 1

The option (2) is CORRECT

Reason : The black deposit it due to formation of 'sooty' flame* .

This occur due to 2 reasons

1) Inadequate oxygen supply

2)Presence of unsaturated hydrocarbon fuel

Both of these conditions lead to incomplete combustion which leads to formation of sooty flame*

(* This flame is yellow in color and gives black colored smoke which is called soot)

I hope it helps.

In Hindi (TRANSLATED BY GOOGLE)

vikalp (2) sahee hai

kaaran: kaalikh kee jvaala * banane ke kaaran kaalee ise jama karatee hai.

yah 2 kaaranon se hota hai

1) aparyaapt oxygen kee aapoorti

2) asantrpt hydrocarbon eendhan kee upasthiti

in donon sthitiyon ke kaaran adhoora dahan hota hai, jo kaalikh kee jvaala ka nirmaan karata hai *

(* yah lau peele rang kee hai aur kaale rang ka dhuaan detee hai jise kaalikh kahate hain)..

Please mark me as BrAiNLiEsT

Answer 2

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While cooking, if the bottom of the vessel is getting blackened on the outside, it means that the fuel is not burning completely. When the fuel burns completely giving a blue flame, the bottom of the vessel remains clean.

When the fuel does not burn completely then a sooty flame appears which makes the bottom of the utensil black. It is due to the air holes, which are getting blocked and the fuel does not burn completely.