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
Correct Answer :
D. 2000-2500°C
Related Questions
The firing order in an I.C. engine depends upon
Arrangement of the cylinders
Design of crankshaft
Number of cylinders
All of these
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%
Theoretically, a four stroke cycle engine should develop _________ power as that of a two stroke cycle engine.
Half
Same
Double
Four times
The pressure inside the cylinder is _________ the atmospheric pressure during the exhaust stroke.
Equal to
Below
Above
None of these
Fuel oil consumption guarantees for I .C. engine are usually based on
Low heat value of oil
High heat value of oil
Net calorific value of oil
Calorific value of fuel
In a diesel engine, the duration between the time of injection and ignition, is known as
Pre-ignition period
Delay period
Period of ignition
Burning period
An engine indicator is used to determine the following
Speed
Temperature
Volume of cylinder
m.e.p. and I.H.P.
If V₁ is the jet velocity and V₀ is the vehicle velocity, then the propulsive efficiency of a rocket is given by
[2(V₀/V₁)]/ [1 + (V₀/V₁)²]
(V₀/V₁)/ [1 + (V₀/V₁)²]
V₀/(V₀ + V₁)
V₁/(V₀ + V₁)
Which of the following does not relate to a compression ignition engine?
Fuel pump
Fuel injector
Governor
Carburettor
In petrol engines, the delay period is of the order of
0.001 second
0.002 second
0.003 second
0.004 second
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 thermal efficiency of diesel engines is about
15 %
30 %
50 %
70 %
The inlet value of a four stroke cycle I.C engine remains open for nearly
180°
125°
235°
200°
The air requirement of a petrol engine during starting compared to theoretical air required for complete combustion is
More
Less
Same
May be more or less depending on engine capacity
A supercharged engine as compared to an ordinary engine
Is lighter
Requires smaller foundations
Consumes less lubricating oil
All of these
In a four stroke cycle petrol engine, the inlet valve
Opens at top dead centre and closes at bottom dead centre
Opens at 20° before top dead centre and closes at 40° after bottom dead centre
Opens at 20° after top dead centre and closes at 20° before bottom dead centre
May open or close anywhere
The effective inhibitor of pre-ignition is
Alcohol
Water
Lead
None of these
Compression loss in I.C engines occurs due to
Leaking piston rings
Use of thick head gasket
Clogged air inlet slots
All of the above
Which of the following fuel has little tendency towards detonation?
Benzene
Iso-octane
Normal heptane
Alcohol
The knocking tendency in compression ignition engines for a given fuel will be
Enhanced by decreasing compression ratio
Enhanced by increasing compression ratio
Dependent on other factors
None of the above
The cetane number of diesel oil, generally available, is
20 to 25
25 to 30
30 to 40
40 to 55
The injection pressure in a diesel engine is about
10 bar
100 bar
150 bar
500 bar
A heat engine utilises the
Calorific value of oil
Low heat value of
High heat value of oil
Mean heat value of oil
The thermal efficiency of diesel engines on weak mixtures is
Unaffected
Lower
Higher
Dependent on other factors
The advancing of spark timing in spark ignition engines will _________ knocking tendency.
Increase
Reduce
Not effect
None of these
In loop scavenging, the top of the piston is
Flat
Contoured
Slanted
Depressed
In a typical medium speed 4-stroke cycle diesel engines
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
The air standard efficiency of an I.C. engine depends on
Fuel used
Speed of engine
Compression ratio
None of these
In order to prevent knocking in spark ignition engines, the charge away from the spark plug should have
Low density
Low temperature
Long ignition delay
All of these
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