The self ignition temperature of petrol is ________ as compared to diesel oil.
Same
Lower
Higher
None of these
Correct Answer :
C. Higher
Related Questions
Which of the following medium is compressed in a Diesel engine cylinder?
Air alone
Air and fuel
Air and lub oil
Fuel alone
The scavenging efficiency of a four stroke cycle diesel engine is
Below 50%
Between 50 and 85%
Between 85 and 95%
Between 95 and 100%
The specific fuel consumption per BHP hour for diesel engine is approximately
0.15 kg
0.2 kg
0.25 kg
0.3 kg
In a cycle, the spark lasts roughly for
1 sec
0.1 sec
0.01 sec
0.001 sec
The working pressure and temperature inside the cylinder of an internal combustion engine is _________ as compared to a steam engine.
Low
Very low
High
Very high
The object of supercharging the engine is
To reduce mass of the engine per brake power
To reduce space occupied by the engine
To increase the power output of an engine when greater power is required
All of the above
In a four stroke cycle petrol engine, the compression
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
The thermodynamic cycle on which the petrol engine works, is
Otto cycle
Joule cycle
Rankine cycle
Stirling cycle
The compression ignition engines are governed by
Hit and miss governing
Qualitative governing
Quantitative governing
Combination of (B) and (C)
An hmh flame speed is obtained in diesel engine when air fuel ratio is
Uniform throughout the mixture
Chemically correct mixture
About 35% of rich mixture
About 10% of rich mixture
The size of inlet valve of an engine in comparison to exhaust valve is
More
Less
Same
More/less depending on capacity of engine
In petrol engine, using a fixed octane rating fuel and fixed compression ratio, supercharging will _________ the knocking tendency.
Not effected
Decrease
Increase
None of these
The calorific value of gaseous fuels is expressed in terms of
kcal
kcal/kg
kcal/m²
kcal/m3
In a typical medium speed 4-stroke cycle diesel engine
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
Polymerisation is a chemical process in which molecules of a compound become
Larger
Slowed down
Smaller
Liquid
A spark plug gap is kept from
0.3 to 0.7 mm
0.2 to 0.8 mm
0.4 to 0.9 mm
0.6 to 1.0 mm
The ratio of indicated thermal efficiency to the corresponding air standard cycle efficiency is called
Net efficiency
Efficiency ratio
Relative efficiency
Overall efficiency
The air standard efficiency of an Otto cycle compared to diesel cycle for the given compression ratio is
Same
Less
More
More or less depending on power rating
A diesel engine has compression ratio from
6 to 10
10 to 15
15 to 25
25 to 40
Which is more viscous lube oil?
SEA 30
SAE 50
SAE 70
SAE 80
The magneto in an automobile is basically
Transformer
D.C. generator
Capacitor
Magnetic circuit
Most high speed compression engines operate on
Otto cycle
Diesel cycle
Dual cycle
Carnot cycle
A diesel engine has
1 valve
2 valves
3 valves
4 valves
In a four stroke cycle petrol engine, the pressure inside the engine cylinder during the suction stroke is __________ the atmospheric pressure.
Equal to
Below
Above
None of these
The ignition of the charge by some hot surface within the engine before the passage of spark is called
Pre-ignition
Detonation
Ignition delay
Auto-ignition
Which one of the following event would reduce volumetric efficiency of a vertical compression ignition engine?
Inlet valve closing after bottom dead centre
Inlet valve closing before bottom dead centre
Inlet valve opening before top dead centre
Exhaust valve closing after top dead centre
In an internal combustion engine, the process of removing the burnt gases from the combustion chamber of the engine cylinder is known as
Scavenging
Detonation
Supercharging
Polymerisation
The air standard efficiency of an I.C. engine depends on
Fuel used
Speed of engine
Compression ratio
None of these
Which of the following is not an interns combustion engine?
2-stroke petrol engine
4-stroke petrol engine
Diesel engine
Steam turbine
Which of the following fuel detonates readily?
Benzene
Iso-octane
Normal heptane
Alcohol