For the same power developed in I.C. engines, the cheaper system is
Naturally aspirated
Supercharged
Centrifugal pump
Turbo charger
Correct Answer :
B. Supercharged
Related Questions
The minimum cranking speed in case of petrol engine is about
Half the operating speed
One fourth of operating speed
250 - 300 rpm
60 - 80 rpm
The operation of forcing additional air under pressure into the engine cylinder is known as
Supercharging
Carburetion
Turbulence
Delay period
A 75 cc engine has following parameter as 75 cc
Fuel tank capacity
Lube oil capacity
Swept volume
Cylinder volume
The voltage required to produce a spark across the gap, between the sparking points is
2000 to 4000 volts
4000 to 6000 volts
6000 to 10,000 volts
10,000 to 12,000 volts
The inlet valve of a four stroke cycle internal combustion engine remains open for
130°
180°
230°
270°
The mean effective pressure obtained from engine indicator indicates the
Maximum pressure developed
Minimum pressure
Instantaneous pressure at any instant
Average pressure
A higher compression ratio causes
Pre-ignition
Increase in detonation
Acceleration in the rate of combustion
Any one of these
The basic requirement of a good combustion chamber is
Minimum turbulence
Low compression ratio
High thermal efficiency and power output
Low volumetric efficiency
The thermal efficiency of petrol and gas engines is about
15 %
30 %
50 %
70 %
A supercharged engine as compared to an ordinary engine
Requires smaller foundation
Is lighter
Consumes less lubricating oil
All of these
The output of a diesel engine can be increased without increasing the engine revolution or size in following way
Feeding more fuel
Heating incoming air
Scavenging
Supercharging
Which of the following statement is correct regarding normal cetane?
It is a standard fuel used for knock rating of diesel engines
Its chemical name is normal hexadecane
It has long carbon chain structure
All of the above
In a four stroke cycle, the minimum temperature inside the engine cylinder occurs at the
Beginning of suction stroke
End of suction stroke
Beginning of exhaust stroke
End of exhaust stroke
Which of the following does not relate to a compression ignition engine?
Fuel pump
Fuel injector
Governor
Carburettor
As a result of detonation in an I.C. engine, following parameter attains very high value
Peak pressure
Rate of rise of pressure
Rate of rise of temperature
Peak temperature
The maximum temperature in the I.C. engine cylinder is of the order of
500-1000°C
1000-1500°C
1500-2000°C
2000-2500°C
The expansion of fuel in a four stroke cycle diesel engine
Starts at 15° before top dead centre and ends at 30° after top dead centre
Starts at top dead centre and ends at 30° after top dead centre
Starts at 15° after top dead centre and ends at 30° before bottom dead centre
May start and end anywhere
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
In order to mix air and petrol in the required proportion and to supply it to the engine during suction stroke, then _________ is employed.
Fuel pump
Injector
Carburettor
None of these
If the compression ratio of an engine working on Otto cycle is increased from 5 to 7, the percentage increase in efficiency will be
2 %
4 %
8 %
14 %
Supercharging is the process of supplying the intake air to the engine cylinder at a density _________ the density of the surrounding atmosphere.
Equal to
Less than
Greater than
None of these
A two stroke cycle engine gives ________ the number of power strokes as compared to the four stroke cycle engine, at the same engine speed.
Half
Same
Double
Four times
The fuel valve in a four stroke cycle diesel engine
Opens at 15° after top dead centre and closes at 20° before bottom dead centre
Opens at 15° before top dead centre and closes at 20° after top dead centre
Opens at top dead centre and closes at bottom dead centre
May open and close anywhere
The fuel air ratio in a petrol engine fitted with suction carburettor, operating with dirty air filter as compared to clean filter will be
Higher
Lower
Remain unaffected
None of the above
Diesel fuel, compared to petrol is
Less difficult to ignite
Just about the same difficult to ignite
More difficult to ignite
Highly ignitable
The power actually developed by the engine cylinder of an I.C. engine is known as
Theoretical power
Actual power
Indicated power
None of these
Crankcase explosion in I.C. engines usually occurs as
First a mild explosion followed by a bi explosion
First a big explosion followed by a mil explosion
Both mild and big explosions occurs simultaneously
Never occurs
Pour point of fuel oil is the
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
Thermal efficiency of a two stroke cycle engine is ________ a four stroke cycle engine.
Equal to
Less than
Greater than
None of these
The specific fuel consumption per B.P. hour for a diesel engine is about
0.2 kg
0.25 kg
0.3 kg
0.35 kg