Question

How is knocking produced in a petrol engine?

(a) Due to the size of the engine

(b) Due to spontaneous combustion in the engine

(c) Due to the presence of less impurities in the fuel

(d) Due to the parts of the engine

This question was addressed to me by my school teacher while I was bunking the class.

Asked question is from Anti Knocking Agents in portion Fuels and Combustion of Engineering Chemistry II

Answer 1

Right answer is (b) Due to spontaneous combustion in the engine

The explanation is: Knocking in petrol engine is due to the spontaneous ignition of the last positions of the compressed mixture of petrol and air. This process of ignition of the mixture relatively slows the induction period.