6
12
18
24
✅ The correct answer is option D.
Fuel and Combustion MCQs
Too much of excess air in combustion results in high
Fuel consumption for the same heat load
Stack gas temperature
Percentage of oxygen in flue gases
All of the above
✅ The correct answer is option D.
Which of the following would require maximum amount of % excess air for complete combustion?
Coke oven gas
Furnace oil
Pulverised coal
Lump coal (fixed on chain grate)
✅ The correct answer is option D.
The cuprous chloride used in orsat apparatus can absorb
Only CO
Both CO and CO₂
Both CO and O₂
All of the above
✅ The correct answer is option D.
Calorific value of bituminous coal may be around __________ Kcal/kg.
500
1500
6500
20000
✅ The correct answer is option C.
Calorific value of gobar gas (containing CH₄ = 60% , H₂ = 10% ; CO₂ = 30%) may be about __________ Kcal/Nm³.
1800
3200
5400
10200
✅ The correct answer is option C.
C.V. (kcal/Nm³) of gaseous fuels __________ with increase in molecular weight.
Decreases
Increases
Remains constant
May increase or decrease, depends on combustibles
✅ The correct answer is option D.
If oxygen content in the flue gas rises too high, fuel is being wasted by
Incomplete combustion
Dry gas/stack gas loss
Moisture loss
None of these
✅ The correct answer is option B.
Quantity of coke produced from metallurgical coal may be around __________ percent.
30
50
75
95
✅ The correct answer is option C.
Abrasion index of blast furnace coke should be around __________ percent.
20
35
55
80
✅ The correct answer is option D.