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
Correct Answer :
B. High heat value of oil
Related Questions
The combustion in compression ignition engines is
Homogeneous
Heterogeneous
Both (A) and (B)
None of these
A diesel engine, during suction stroke, draws
Air only
Diesel only
A mixture of diesel and air
None of these
Gaseous fuel guarantees are based on
Calorific value of oil
Low heat value of oil
High heat value of oil
Mean heat value of oil
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 accumulation of carbon in a cylinder results in increase of
Clearance volume
Volumetric efficiency
Ignition time
Effective compression ratio
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
Volatility of diesel fuel oil is
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
As compared to air standard cycle, in actual working, the effect of variation in specific heats is to
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
A supercharged engine as compared to an ordinary engine
Requires smaller foundation
Is lighter
Consumes less lubricating oil
All of these
The function of a distributor in a coil ignition system of I.C. engines is
To distribute spark
To distribute power
To distribute current
To time the spark
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
The air-fuel ratio in petrol engines is controlled by
Controlling valve opening/closing
Governing
Injection
Carburetion
Thermal efficiency of a two stroke cycle engine is ________ a four stroke cycle engine.
Equal to
Less than
Greater than
None of these
A diesel engine as compared to petrol engine (both running and rated load) is
More efficient
Less efficient
Equally efficient
Other factors will decide it
By higher octane number of spark ignition fuel, it is meant that the fuel has
Higher heating value
Higher flash point
Lower volatility
Longer ignition delay
In the opposed piston diesel engine, the combustion chamber is located
Above the piston
Below the piston
Between the pistons
There is no such criterion
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
Diesel as compared to petrol is
Highly ignitable
More difficult to ignite
Less difficult to ignite
None of these
In diesel engine the diesel fuel injected into cylinder would burn instantly at about compressed air temperature of
250°C
500°C
1000°C
2000°C
The cetane number of diesel oil, generally available, is
20 to 25
25 to 30
30 to 40
40 to 55
If the intake air temperature of I.C. engine increases, its efficiency will
Increase
Decrease
Remain same
None of these
A higher compression ratio causes
Pre-ignition
Increase in detonation
Acceleration in the rate of combustion
Any one of these
Pick up the false statement
Thermal efficiency of diesel engine is about 34%
Theoretically correct mixture of air and petrol is approximately 15:1
High speed compression engines operate on dual combustion cycle
S.I. engines are quality governed engines
A diesel engine has
One valve
Two valves
Three valves
Four valves
The thermal efficiency of a diesel cycle having fixed compression ratio, with increase in cut-off ratio will
Increase
Decrease
Be independent
May increase or decrease depending on other factors
Which of the following fuel has little tendency towards detonation?
Benzene
Iso-octane
Normal heptane
Alcohol
The knocking in diesel engines may be prevented by
Reducing the delay period
Raising the compression ratio
Increasing the inlet pressure of air
All of these
The reflectivity depends upon
Geometry of the reflector
Energy of neutrons
Properties of the reflector
All 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
In diesel engine, the compression ratio in comparison to expansion ratio is
Same
Less
More
Variable