Problem 2) (chapter41 Read about the combustion processes in the engine (Spark ignition & compression ignition) and explain the following: Spark ignition: 1) Sparked ignition Air-fuel mixture 2) Sparked ignition circuits (primary and secondary circuits) 3) Abnormal combustion (knock) in the spark-ignition engines Compression ignition: 1) Compression ignition air-fuel mixture 2) Ignition delay Please support your answer with proper graphs or diagrams (don't forget to state the reference)