191. When the coal is heated in absence of air, it is called its
Deoxidation
Gasification
Coalification
Carbonisation
✅ The correct answer is option D.
Fuel and Combustion MCQs
192. The ratio of % total carbon obtained in the ultimate analysis of coke and % fixed carbon obtained in the proximate analysis is always
1
< 1
> 1
Unpredictable
✅ The correct answer is option C.
193. The temperature at which plastic layer formation takes place during carbonisation of coal varies from __________ °C.
100 to 150
350 to 450
550 to 650
700 to 850
✅ The correct answer is option B.
194. Use of pulverised coal in boiler furnace provides
High calorific value
Better combustion
Smokeless burning
Less erosion on furnace walls
✅ The correct answer is option B.
195. For the case of a fuel gas undergoing combustion with air, if the air/fuel ratio is increased, the adiabatic flame temperature will
Increase
Decrease
Increase or decrease depending on the fuel type
Not change
✅ The correct answer is option B.
196. Calorific value of pitch creosote mixture (PCM) i.e., C.T.F.-200 is about
8800 kcal/m³
8800 kcal/kg
Same as that of coal middling
25000 kcal/kg
✅ The correct answer is option B.
197. Caking index of the coal blend used for the manufacture of metallurgical coke should be around
5
21
40
48
✅ The correct answer is option B.
198. Coalification means the
Process of conversion of lignite into anthracite
Underground gasification of coal
Complete combustion of coal
Direct hydrogenation of coal
✅ The correct answer is option A.
199. The heat of combustion of a fuel
Is equal to the heat of formation
Is always negative
Can’t be known without calculating it
Is always positive
✅ The correct answer is option B.
200. Coke compared to the coal from which it has been made, contains
Less volatile matter
More carbon
Greater percentage of ash
All of the above
✅ The correct answer is option D.