Automobile Engineering in ME
The auto ignition in a spark ignition engine means

Ignition induced by the passage of a spark
Ignition induced to supplement the process of normal combustion
Automatic ignition of the charge at the end of compression
Ignition of the charge before the passage of flame front

ANSWER DOWNLOAD EXAMIANS APP

Automobile Engineering in ME
The compression ratio in petrol engine is kept less than in Diesel engine because

Higher or equivalent compression ratio in petrol engines is not possible due to pre-ignition
It is just customary to have less compression ratio in petrol engines
Less compression ratio gives better performance
It makes petrol engines lighter

ANSWER DOWNLOAD EXAMIANS APP