Internal Combustion Engines
The two reference fuels used for cetane rating are

Cetane and iso-octane
Cetane and normal heptane
Cetane and alpha-methyl naphthalene
Cetane and tetra ethyl lead

ANSWER DOWNLOAD EXAMIANS APP

Internal Combustion Engines
In a four stroke cycle diesel engine, the compression

Starts at 40° before top dead center and ends at 40° after top dead center
Starts at 40° after bottom dead center and ends at 10° before top dead center
May start and end anywhere
Starts at top dead center and ends at 40° before bottom dead center

ANSWER DOWNLOAD EXAMIANS APP