Gasohol is a mixture of
Advantage of hydrogen as an IC engine fuel
Advantages of hydrogen as an IC engine fuel:
1. Low emissions
2. Fuel availability
3. Fuel leakage is not a pollutant
4. High energy content per unit volume
Consider the following advantages/ disadvantages of using hydrogen as a fuel:
1. It has high Nox emissions due to high flame temperature.
2. Fuel leakage to environment is not a pollutant.
3. It has high energy content per volume when stored as a liquid.
4. It requires heavy, bulky fuel storage both in vehicle and at the service stations.
5. It has very good engine volumetric efficiency.
Q. Which of the above are correct ?
It has poor engine volumetric efficiency. Anytime gaseous fuel is used in an engine, the fuel will displace some of the inlet air and poorer volumetric efficiency will result.
Which of the following can’t be used to produce biodiesel ?
A variety of oils can be used to produce biodiesel and these include:
Major disadvantage of LPG as a fuel in automobile are:
1. Reduction in the life of the engine.
2. Less power compared to gasoline.
3. Knocking tendency.
Q. Which of the above is/are correct ?
Consider the following advantages/disadvantages of LPG as a fuel and pick the correct options:
1. Emission is much reduced by the use of LPG.
2. LPG has very poor antiknock characteristics.
3. Due to absence of carbon deposits on the electrodes of the spark plug, the life of spark plug increases.
4. LPG is. having strong odour.
5. The vehicle weight increases due to LPG cylinders.
Advantages of LPG:
If petrol is used in a diesel engine, then
If diesel is fed by mistake in the oil tank of a petrol engine, then engine will
The bi-fuel engine uses
Performance numbers are
Each octane number at the higher range of the octane scale will produce greater anti-knock effect compared to the same unit at the lower end of the scale. Because of this non-linear variation, a new scale was derived which expresses the approximate relative engine performance.
Knock resistance property of diesel oil can be improved by adding small quantities of compounds except
The antifreeze solution commonly used in automobiles is
Octane number of natural gas is
Vapour lock is
The possible cause of smoky exhaust in a diesel engine could be
1. un-even distribution of fuels to cylinders.
2. exhaust valve receives too much lube oil.
3. fuel injection is late
4. water in the fuel
5. fuel injector is not adjusted right
Q. Which of these statements are correct ?
Stoichiometric air-fuel ratio of petrol is roughly
For petrol, stoichiometric air-fuel ratio is around 15 : 1.
The tendency of petrol to detonate in terms of octane number is determined by comparison of fuel with which of the following?
In the octane number test the performance of unknown gasoline is compared with that of series of reference fuels consisting of mixtures of iso-octane and normal heptane.
Octane number of Iso-octane is
Since Iso-octane has a very little tendency to knock and hence it has assigned an octane number of 100.
Ignition quality of diesel fuel is indicated by its
In case of diesel fuel, its ability to auto-ignite quickly is measured by cetane number.
The Cetane number of automotive diesel fuel used in India is in which one of the following ranges?
Cetane number: The cetane rating of a diesel fuel is a measure of its ability to autoignite quickly when it is injected into the compressed and heated air in the engine, ignition delay is affected by several engine design parameter such as compression ratio, injection time, inlet air temperature etc. It is also dependent on hydrocarbon compression of fuel and to some extent on its volatility characteristics. The cetane number is a numerical measure of the influence. The diesel fuel has in determining the ignition delay. Higher the cetane rating of fuel lesser is the property for diesel knock. In India, cetane number lies between 40 to 60.