281. Yield of coke oven gas in low temperature carbonisation of coal is about __________ Nm³ /ton of dry coal.
60
160
500
750
✅ The correct answer is option B.
Fuel and Combustion MCQs
282. When incomplete combustion loss is high, the flue gas analysis shows large amount of
CO₂
CO
O₂
C
✅ The correct answer is option B.
283. Turndown ratio of a gas burner is equal to the
Maximum to minimum heat input ratio
Maximum to minimum permissible gas flow rate
Both A & B
Minimum to maximum heat input ratio
✅ The correct answer is option C.
284. Flue gas discharge velocity through chimney of a big thermal power plant may be around __________ m/sec.
0.5
10
50
500
✅ The correct answer is option B.
285. Pensky-Marten apparatus is used for those oils, whose flash points are __________ °F.
<120
>120
<90
90-110
✅ The correct answer is option B.
286. Gobar gas is produced by the __________ of cown dung.
Fermentation
Oxidation
Hydrogenation
None of these
✅ The correct answer is option A.
287. Combustion of pulverised coal compared to the lumpy coal
Provides better control of furnace temperature
Facilitates combustion with lower excess air
Provides higher thermal efficiency & flame temperature
All of the above
✅ The correct answer is option D.
288. With increases in carbonisation temperature
Coke even gas yield increases
Tar yield increases
Hydrogen percentage in the coke oven gas decreases
Methane percentage in the coke oven gas increases
✅ The correct answer is option A.
289. Oxygen content in a flue gas was found to be 4%. It implies that excess air used for combustion was around __________ percent.
4
96
20
40
✅ The correct answer is option C.
290. Washing of coal does not reduce its
S & P content
Heating value
Fusion point of ash
None of these
✅ The correct answer is option D.