I. C. Engines

Paraffin, aromatic, napthene ✘ Paraffin, napthene, aromatic ✘ Napthene, aromatics, paraffin ✘ Napthene, paraffin, aromatic ✔

Retarding the spark ✘ Increasing the engine speed ✘ Both and ✘ None of these ✔

Speed ✘ Temperature ✘ Volume of cylinder ✘ m.e.p. and I.H.P. ✔

Opens at 30 ✘ Opens at 30 ✘ Opens at bottom dead centre and closes at top dead centre ✘ May open and close anywhere ✔

6 kg/cm ✘ 12 kg/cm ✘ 20 kg/cm ✘ 35 kg/cm ✔

High self ignition temperature ✘ Low volatility ✘ Higher viscosity ✘ All of these ✔

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 ✘ Temperature at which it solidifies or congeals ✘ It catches fire without external aid ✘ Indicated by 90% distillation temperature i.e., when 90% of sample oil has distilled off ✔

Starts at 40 ✘ Starts at 40 ✘ Starts at bottom dead centre and ends at top dead centre ✘ May start and end anywhere ✔

500-1000 ✘ 1000-1500 ✘ 1500-2000 ✘ 2000-2500 ✔

Haphazard motion of the gases in the chamber ✘ Rotary motion of the gases in the chamber ✘ Radial motion of the gases in the chamber ✘ None of the above ✔