1. Presence of ______________ in dry gaseous fuel does not contribute its calorific value.
a) hydrogen
b) sulphur
c) oxygen
d) carbon
Answer
Answer: c [Reason:] Oxygen does not contribute to the calorific value of dry gaseous fuels.
2. Improper storage condition results weathering of coal and spontaneous combustion, which increases its
a) caking index
b) yield of carbonised products
c) calorific value
d) friability and oxygen content
Answer
Answer: d [Reason:] Improper storage of coal causes loss of oxygen content, resulting in loss of heat value.
3.Laboratory gas is obtained by cracking of
a) fuel oil
b) gasoline
c) kerosene
d) diesel
Answer
Answer: c [Reason:] Kerosene on cracking gives laboratory gas.
4.Higher percentage of ash in coal meant for the production of metallurgical grade coke
a) causes brittleness in coke
b) increases abrasion resistance of coke
c) decreases hardness of coke
d) causes high toughness
Answer
Answer: b [Reason:] A high percentage of ash in coal meant for production of metallurgical grade coke causes an increase in abrasion resistance in coke.
5. Carbon content by weight in air dried wood may be about _____________ %.
a) 25
b) 50
c) 10
d) 80
Answer
Answer: b [Reason:] Air dried wood has carbon content of about 50%.
6. Softening temperature of coal is a measure of which tendency of coal?
a) clinkering tendency
b) coking tendency
c) caking tendency
d) size tendency
Answer
Answer: a [Reason:] Clinkering tendency is responsible for the softening of coal.
7. Combustion of pulverised coal as compared to lump coal
a) can be done with less excess air
b) develops a low temperature flame
c) develops a non-luminous flames
d) provides a lower rate of heat release
Answer
Answer: a [Reason:] Pulverisation leads to less use of air.
8. Dry air required to burn 1kg of carbon completely may be around ________________ kg.
a) 11
b) 38
c) 2
d) 20
Answer
Answer: a [Reason:] 11kg of dry air is required to burn 1kg of carbon.
9. ‘Fat coal’ means a coal having
a) high volatile matter
b) low ash content
c) low calorific value
d) non-smoking tendency
Answer
Answer: a [Reason:] Coal having high volatile matter is called ‘fat coal’.
10. A good quality coal should have
a) high ash content
b) high sulphur
c) low fusion point of ash
d) none of the mentioned
Answer
Answer: d [Reason:] A good quality coal should have high carbon content.
11. Grindability of coal is 100. It implies that
a) it can’t be pulverised
b) it is easily pulverised
c) can be pulverised with difficulty
d) power consumption is high in pulverisation
Answer
Answer: b [Reason:] High grindability of coal implies easy pulverisation.
12. The difference in total carbon and fixed carbon of coal will be minimum in case of
a) lignite
b) bituminous coal
c) high temperature coke
d) anthracite
Answer
Answer: c [Reason:] Out of these options, high temperature coke has minimum difference.
13. Fuel gases containing hydrocarbons are not preheated before burning, because
a) they crack, thereby choking and fouling heat transfer surface
b) it reduces calorific value tremendously
c) it reduces flame temperature tremendously
d) there are chances of explosion during preheating
Answer
Answer: a [Reason:] Hydrocarbons crack easily, hence they are not preheated.
