Injection 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 pluger starts to pump fuel
C. time corresponding to actual injection and top dead center
D. time corresponding to actual ignition and top dead center
E. none of the above

In open combustion chamber in diesel engines____________________?

A. the shape and layout of the piston crown, the inlet port, and the valve produce the turbulent effect on fuel mixture
B. fuel is injected into an auxiliary chamber that is separated from the cylinder by an orifice or throat
C. only a part of air charge is contained in an auxiliary chamber in which the fuel starts to burn with insufficient air which due to explosion tendency mixes thoroughly into main cylinder charge
D. fuel is injected at atmospheric pres¬sure
E. there are no valves.

In a typical medium speed 4-stroke cycle diesel engine________________?

A. compression starts at 35° after bottom dead center and ends at top dead center
B. compression starts at bottom dead center and ends at top dead center
C. compression starts at 10° before bottom dead center and, ends just before top dead center
D. may start and end anywhere
E. none of the above

In a typical medium speed 4 stroke cycle diesel engine_______________?

A. exhaust valve opens at 35° before bot-tom dead center and closes at 20° after top dead center
B. exhaust valve opens at bottom ‘dead center and closes at top dead center
C. exhaust valve opens just after bottom dead center and closes just before top dead center
D. may open and close anywhere
E. none of the above is true

In a typical medium speed, 4-stroke cycle diesel engine ___________________?

A. fuelinjection starts at 10° before to dead center and ends at 20° after tor dead center
B. fuel injection starts at top dead center and ends at 20° after top dead center
C. fuel injection starts at just before top dead center and ends just after top deac center
D. may start and end anywhere
E. none of the above

Cetane___________________?

A. has zero cetane number
B. has 100 cetane number
C. helps detonation
D. is a straight chain paraffin
E. determines the efficiency of an I.C. engine

Compression ratio of LC. engines is ___________________?

A. the ratio of volumes of air in cylinder before compression stroke and after compression stroke
B. volume displaced by piston per stroke and clearance volume in cylinder
C. ratio of pressure after compression and before compression
D. swept volume/cylinder volume
E. cylinder volume/swept volume

For the same compression ratio_____________________?

A. Otto cycle is more efficient than the Diesel
B. Diesel cycle is more efficient’than Otto
C. both Otto and Diesel cycles are, equally efficient
D. compression ratio has nothing to do with efficiency
E. which is more efficient would depend on engine capacity

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

Flash point of fuel oil is __________________?

A. minimum temperature to which1 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. temperature 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. none of the above

Supercharging is the process of_____________________?

A. supplying the intake of an engine with air at a density greater than the density of the surrounding atmosphere
B. providing forced cooling air
C. injecting excess fuel for raising more load
D. supplying compressed air to remove combustion products fully
E. raising exhaust pressure

Supercharging is the process of_____________________?

A. supplying the intake of an engine with air at a density greater than the density of the surrounding atmosphere
B. providing forced cooling air
C. injecting excess fuel for raising more load
D. supplying compressed air to remove combustion products fully
E. raising exhaust pressure

Iso-oct ,ne________________?

A. has octane number of 0
B. has octane number of 50
C. has octane number of 100
D. is an index of detonation quality
E. is an index of knocking quality

In turbulence chamber in diesel engine__________________?

A. the shape and layout of the piston crown, the inlet port, and the valve produce the turbulent effect of fuel mixture
B. fuel is injected into an auxiliary chamber that is separated from the cylinder by an orifice or throat
C. only a part of air charge is contained in an auxiliary chamber in which the fuel starts to burn with insufficient air which due to explosion tendency mixes thoroughly into main cylinder charge
D. there are no valves
E. fuel is partly burnt by spark