Engineering Chemistry Multiple Choice Questions on “Liquid Fuels”.
1. How can we obtain liquid coal synthetically?
a) Carbonisation of coal
b) Hydrogenation of coal
c) By heating of coal
d) By cooling of coal
Answer: b
Clarification: Highly volatile bituminous coal is used for the hydrogenation process. The hydrogenation of bituminous coal produces liquid hydrocarbons which have a number of uses in many processes. It is obtained by the Bergius process.
2. In which processes does the low boiling fractions of petroleum are used?
a) Petrol engines
b) Diesel engines
c) Oil fired furnaces
d) Kerosene engines
Answer: a
Clarification: At low boiling fractions of petroleum least amount of impurities are left and since the efficiency petrol engine decreases with the increase in the amount of impurities, these fractions are used in petrol engines. At high boiling fractions, diesel engines and oil fired furnaces are used.
3. Which of the following fuel requires less storage space?
a) Methane gas
b) Coal
c) Cow dunk
d) Kerosene
Answer: d
Clarification: Liquid fuels require less storage space as compared to solid and gaseous fuel. Kerosene weigh 30% less and occupy 50% less space than coal of equal heating value. Gaseous fuel are weigh very less, but their storage requires a big space.
4. Liquid fuels leave ash content after burning.
a) True
b) False
Answer: b
Clarification: Both liquid and gaseous fuel does not produce ash content after burning as solid fuel. The problem of clinker formation is totally absent in case of liquid fuel.
5. Which type of combustion is seen in liquid fuel?
a) Uniform and complete combustion
b) Non-uniform and complete combustion
c) Uniform and incomplete combustion
d) Non-uniform and incomplete combustion
Answer: a
Clarification: The rate of combustion in the case of liquid fuels can be controlled easily. Also since there is no ash generation in liquid fuel, it undergoes complete combustion.
6. Which of the following fuel does not requires excess air for its combustion?
a) Coal
b) Cow-dunk cake
c) Diesel
d) Charcoal
Answer: c
Clarification: Liquid fuel such as diesel does not require excess air for their combustion, they normally start combustion on catching fire where as in solid fuels excess air is required for the process of combustion. Pulverised coal does not require excess air for combustion.
7. Liquid fuel produces _____________ odours on incomplete combustion.
a) Pleasant
b) Unpleasant
c) No odours
d) Fruity
Answer: b
Clarification: Sometimes due to the presence of impurities, incomplete combustion of liquid fuel occurs which produces very unpleasant odours which can also be hazardous for health. For this process purification method is used.
8. What happens when liquid fuels evaporate?
a) It increases its calorific value
b) It reduces the impurities present in it
c) It increase the ash content present in it
d) It makes losses and leakages in the container
Answer: d
Clarification: The containers in which the liquid fuels are stored are made of special material due the possibility of losses due to evaporation and leakage in the containers. The liquid fuels cannot be stored in containers for long time.
9. Which kind of liquid fuels are risky to store?
a) Flammable and volatile
b) Inflammable and volatile
c) Flammable and non-volatile
d) Inflammable and non-volatile
Answer: b
Clarification: I the temperature of the surrounding increases to a high value, then the inflammable liquid fuels will burn quickly. And the presence of volatile matter will cause the liquid fuels to burn with long flames.
10. Which kind of burners are used for efficient combustion of liquid fuels?
a) Wesman burner
b) Dual-fuel burner
c) Oil burners
d) Pressure jet burner
Answer: a
Clarification: Wesman burner is used of high efficiency combustion of both liquid and gaseous fuel. Special types of sprayers are also used efficient combustion of liquid fuels.