Q.1
Coking coals are invariably
Q.2
Gobar gas is produced by the __________ of cown dung.
Q.3
Efficiency of the combustion of a fuel is judged by the __________ the flue gas.
Q.4
The catalyst used in shift converter is
Q.5
Which of the following has the highest gross calorific value?
Q.6
Highly reactive coke have lower
Q.7
Which of the following accounts for maximum energy loss in a boiler?
Q.8
Pulverised coal used in boiler firing need not have
Q.9
Mineral matter, 'M' and ash percentage 'A' in coal are roughly related as
Q.10
The advantage of firing pulverised coal in the furnace lies in the fact, that it
Q.11
Naphthalene is used for making
Q.12
Which of the following is not increased by using preheated combustion air in place of ordinary air at room temperature?
Q.13
Coal is heated in absence of air for 7 minutes at a temperature of about __________ °C, during its volatile matter determination for proximate analysis.
Q.14
Function of secondary air in pulverised coal firing is to
Q.15
'Mixed gas' used in steel plants is a mixture of
Q.16
High amount of sulphur and phosphorous in coke causes
Q.17
Which of the following constituents of coal is the most important in the production of coke?
Q.18
Low temperature oxidation of coal resulting from bad storage conditions does not decrease its
Q.19
The calorific value of a gas of composition CO₂ = 20%, H₂ = 50%, CH₄ = 30%, is y. If the composition of gas is changed to H₂ = 50%, CH₄ = 30%, CO₂ = 10%, N₂ = 10%, then the calorifice value will be
Q.20
Blast furnace coke is made from coal by
Q.21
Blast furnace gas constitutes mainly of
Q.22
Washing of coal does not reduce its
Q.23
Benzol is used
Q.24
Coking time in a commercial high temperature coal carbonisation plant is about __________ hours.
Q.25
Nitrogen in coal
Q.26
Oxygen required for theoretically complete combustion of 1 Nm³ methane is __________ Nm³.
Q.27
Pick out the wrong statement.
Q.28
Bomb calorimeter can be used to determine the __________ of the coal.
Q.29
A liquid/gaseous fuel containing hydrocarbons and high amount of sulphur is burnt with 40% excess air. The flue gas still contains large amount of carbon monoxide. This may be due to the
Q.30
Coking time in narrow by-product coke ovens is around __________ hours.
Q.31
Calorific values of both the solid as well as the liquid fuels can be determined by __________ calorimeter.
Q.32
Calorific value as determined by bomb calorimeter is the
Q.33
Which of the following is the most poisonous gas?
Q.34
Efficient burning of anthracite coal requires
Q.35
Caking index of a coal is a measure of its
Q.36
Micum Index of a coke is a measure of its
Q.37
Weathering of coal during storage causes
Q.38
Low temperature oxidation of coal is accelerated by the
Q.39
Dry air requirement for burning 1 Nm³ of CO to CO₂ may be around __________ Nm³.
Q.40
Low temperature oxidation and spontaneous combustion of freshly mined coal is accentuated, if
Q.41
If oxygen content in the flue gas rises too high, fuel is being wasted by
Q.42
Coking time in beehive coke oven is about
Q.43
The calorific value of producer gas is around __________ kcal/Nm³
Q.44
Yield of pitch from distillation of high temperature tar is around __________ percent.
Q.45
Rate of low temperature oxidation of coal due to bad storage conditions
Q.46
Washing of coal is done to reduce the
Q.47
Pitch creosote mixture (PCM) as compared to furnace oil is a better fuel, because its
Q.48
The calorific value of natural gas is about __________ kcal/Nm³.
Q.49
Pick out the wrong statement.
Q.50
With increase in moisture content of coal, its
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