Four stroke C.I. engine, four stroke S.I. engine, two stroke S.I. engine
Four stroke S.I. engine, four stroke C.I. engine, two stroke S.I. engine
Four stroke C.I. engine, two stroke S.I. engine, four stroke S.I. engine
Two stroke S.I. engine, four stroke S.I. engine, four stroke C.I. engine
A. Four stroke C.I. engine, four stroke S.I. engine, two stroke S.I. engine
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
In compression ignition engines, detonation occurs near the beginning of combustion.
Since the fuel, in compression ignition engines, is injected at the end of compression stroke, therefore, there will be no pre-ignition.
To eliminate knock in compression ignition engines, we want to achieve auto-ignition not early and desire a long delay period.
In compression ignition engines, because of heterogeneous mixture, the rate of pressure rise is comparatively lower.
Mechanical efficiency
Overall efficiency
Indicated thermal efficiency
Volumetric efficiency
Flat
Contoured
Slanted
Depressed
Otto cycle
Diesel cycle
Dual combustion cycle
All of these
Half the operating speed
One fourth of operating speed
250 - 300 rpm
60 - 80 rpm
Compression ratio for petrol engines varies from 6 to 10
Higher compression ratio in diesel engines results in higher pressures
Petrol engines work on Otto cycle
All of the above
8 : 1
10 : 1
15 : 1
20 : 1 and less
Thermal efficiency
Speed
Power output
Fuel consumption
Diesel
Kerosene
Fuel oil
Gasoline
0.2 kg
0.25 kg
0.3 kg
0.35 kg
Otto cycle
Diesel cycle
Dual cycle
Carnot cycle
Alcohol
Water
Lead
None of these
Enhance flow rate
Control air flow
Induce primary swirl
Induce secondary turbulence
1 valve
2 valves
3 valves
4 valves
Increase maximum pressure and maximum temperature
Reduce maximum pressure and maximum temperature
Increase maximum pressure and decrease maximum temperature
Decrease maximum pressure and increase maximum temperature
High self ignition temperature
Low volatility
Higher viscosity
All of these
One valve
Two valves
Three valves
Four valves
ηm = B.P/I.P
ηm = I.P/B.P
ηm = (B.P × I.P)/100
None of these
Starts at 40° after bottom dead centre and ends at 30° before top dead centre
Starts at 40° before bottom dead centre and ends at 30° after bottom dead centre
Starts at bottom dead centre and ends at top dead centre
May start and end anywhere
Not effected
Decrease
Increase
None of these
Leaking piston rings
Use of thick head gasket
Clogged air inlet slots
All of the above
Larger
Slowed down
Smaller
Liquid
Half
Same
Double
Four times
25 %
50 %
70 %
100 %
Transformer
D.C. generator
Capacitor
Magnetic circuit
1000 km/h
2000 km/h
2400 km/h
3000 km/h
2 %
4 %
8 %
14 %
Net efficiency
Efficiency ratio
Relative efficiency
Overall efficiency
Prevent sparking across the gap between the points
Cause more rapid break of the primary current, giving a higher voltage in the secondary circuit
Both (A) and (B)
None of the above