Question

fuel X which neither leaves any residue on burning nor does it emit any smoke on combustion .What fuel is X ? *​

Answer 1

Hence, the correct answer is Coal  .

Answer 2

Fuel 'X' is LPG.

Explanation:

• Substances such as charcoal, coal, petrol, diesel, LPG, Wood and CNG are used as fuel for various day to day activities.
• The condition given for the identification of fuel is it must be residue free and smoke free.
• The only fuel which falls exactly under this two criteria is liquified petroleum gas (LPG).
• In case of wood, charcoal and coal, on combustion they emit smoke as well as yields ashes as residue.
• LPG is made of propane and butane gases and it is widely used in cooking and fuel for vehicles too.