Carbon is deposited in the exhaust pipes of cars because of

A.

presence of additives in petrol

B.

incomplete combustion of petrol

C.

presence of carbon in petrol

D.

contamination of petrol with diesel

Correct answer is B

Carbon is deposited in the exhaust pipes of cars primarily because of incomplete combustion of petrol. When the fuel (petrol) is burned in the engine's combustion chamber, ideally, it should be fully oxidized, resulting in the production of carbon dioxide (CO2) and water vapor. However, in real-world conditions, the combustion process may not be perfect, and some of the carbon in the petrol may not fully burn. As a result, carbon particles are formed and get carried through the exhaust system.