441. Use of preheated air for combustion of fuel in the furnace, increases the
Scale losses of the furnace stock
Calorific value of the fuel
Flame temperature
None of these
✅ The correct answer is option C.
Fuel and Combustion MCQs
442. Low temperature oxidation of coal is accelerated by the
Storage in large heaps
Storage in compressed piles
Absence of porous or friable particles
All of the above
✅ The correct answer is option A.
443. Calorific value of coal middling generated in coal washeries during washing of coal may be around __________ Kcal/kg.
1000
4000
6000
8000
✅ The correct answer is option B.
444. Micum Index of a coke is a measure of its
Reactivity
Porosity
Bulk density
Hardness & strength
✅ The correct answer is option D.
445. Ash content in the coke produced from a coking coal having 20% ash may be around __________ percent.
6
12
18
24
✅ The correct answer is option D.
446. 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.
447. 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.
448. 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.
449. Calorific value of bituminous coal may be around __________ Kcal/kg.
500
1500
6500
20000
✅ The correct answer is option C.
450. 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.