question_answer

Which of the following are the assumptions involved in the auto-ignition theory put forth for the onset of knock in SI engines?

1. Flame velocity is normal before the onset of auto ignition.

2. A number of end-gas elements auto ignite simultaneously.

3. Preflame reactions are responsible for preparing the end-gas to ignite.

Select the correct answer using the codes given below:

A) 1 and 2            

B) 1 and 3

C) 2 and 3            

D) 1, 2 and 3