Auto-ignition temperature is____________________?

Auto-ignition temperature is____________________?

A. minimum temperature to which oil is heated in order to give off inflammable vapours in sufficient quantity to ignite momentarily when brought in contact with a flame
B. temperature at which it solidifies or congeals
C. that at which it catches fire without external aid
D. indicated by 90% distillation temperature, i.e., when 90% of sample oil has distilled off
E. indicated by 50% distillation temperature

Ethyl fluid is used_______________________?

Ethyl fluid is used_______________________?

A. to increase the octane rating of the fuel
B. to increase the cetane rating of the fuel
C. as a defrosting agent
D. as a superior type of fluid compared to others
E. to improve lubricating quality of fuel

Normal heptane_______________?

Normal heptane_______________?

A. accelerates auto-ignition
B. helps to resist auto-ignition
C. does not affect auto-ignition
D. has no relation with auto-ighition
E. retards auto-ignition

Ignition lag is__________________?

Ignition lag is__________________?

A. the time taken by fuel after injection (before top dead center) to reach upto auto-ignition temperature
B. time before actual fuel injection and the pump plunger starts to pump fuel
C. time corresponding to actual injection and top dead center
D. time corresopnding to actual ingition and top dead center
E. none of the above