Supercharging
Carburetion
Turbulence
Delay period
A. Supercharging
Uniform throughout the mixture
Chemically correct mixture
About 35% of rich mixture
About 10% of rich mixture
Using additives in the fuel
Increasing the compression ratio
Adherence to proper fuel specification
Avoidance of overloading
Mechanical efficiency
Overall efficiency
Volumetric efficiency
Relative efficiency
Exhaust valve opens at 35° before bottom dead centre and closes at 20° after top dead centre
Exhaust valve opens at bottom dead centre and closes at top dead centre
Exhaust valve opens just after bottom dead centre and closes just before top dead centre
May open and close anywhere
Calorific value of oil
Low heat value of oil
High heat value of oil
Mean heat value of oil
0.3 kg/hr
1 kg/hr
3 kg/hr
5 kg/hr
Not effected
Decrease
Increase
None of these
0.3 to 0.7 mm
0.2 to 0.8 mm
0.4 to 0.9 mm
0.6 to 1.0 mm
Supercharging reduces knocking in diesel engines
There can be limited supercharging in petrol engines because of detonation
Supercharging at high altitudes is essential
Supercharging results in fuel economy
Compression starts at 35° after bottom dead center and ends at top dead center
Compression starts at bottom dead center and ends at top dead center
Compression starts at 10° before bottom dead center and, ends just before top dead center
May start and end anywhere
Hit and miss governing
Qualitative governing
Quantitative governing
Combination of (B) and (C)
Larger
Slowed down
Smaller
Liquid
kcal
kcal/kg
kcal/m²
kcal/m3
The ratio of volumes of air in cylinder before compression stroke and after compression stroke
Volume displaced by piston per stroke and clearance volume in cylinder
Ratio of pressure after compression and before compression
Swept volume/cylinder volume
1 m3
5 m3
56 m3
910 m3
0
50
100
120
Enhanced by decreasing compression ratio
Enhanced by increasing compression ratio
Dependent on other factors
None of the above
75% iso-octane and 25% normal heptane
75% normal heptane and 25% iso-octane
75% petrol and 25% diesel
75% diesel and 25% petrol
Equal to
Below
Above
None of these
Low power will be produced
Efficiency will be low
Higher knocking will occur
Black smoke will be produced
0.001 second
0.002 second
0.003 second
0.004 second
Higher
Lower
Remain unaffected
None of the above
Exhaust will be smoky
Piston rings would stick into piston grooves
Engine starts overheating
Scavenging occurs
The friction is high
The friction is unpredictable
The small difference in cooling water temperature or in internal friction has a disproportionate effect
The engine is rarely operated
More
Less
Same
May be more or less depending on engine capacity
Arrangement of the cylinders
Design of crankshaft
Number of cylinders
All of these
0
50
100
120
Cetane number
Octane number
Calorific value
None of these
Highly ignitable
More difficult to ignite
Less difficult to ignite
None of these
Geometry of the reflector
Energy of neutrons
Properties of the reflector
All of these