111. As time passes, the calorific value of stored coal
Decreases
Increases
Remains unaltered
May increase or decrease (depends on the method of storage)
✅ The correct answer is option A.
Fuel and Combustion MCQs
112. Low temperature oxidation of coal during storage does not decrease its
Oxygen content
Caking power
Calorific value
None of these
✅ The correct answer is option D.
113. A gaseous fuel in order to develop luminousity on burning, must contain
Carbon monoxide
Hydrocarbons
Hydrogen
Oxygen
✅ The correct answer is option B.
114. The weathering index of a coal
Gives an idea of the fusion temperature of ash
Is related to its calorific value
Is a measure of its size stability, when stored & exposed to weather
Is a measure of its caking tendency
✅ The correct answer is option C.
115. Percentage of carbon monoxide in blast furnace gas may be around
8
14
22
52
✅ The correct answer is option C.
116. Optimum preheating temperature for pitch creosote mixture (PCM) which is also termed as C.T.F-200, before atomisation through burners is
200 °F
200 °C
200 °K
200 °R
✅ The correct answer is option A.
117. Calorific value of tar is about __________ Kcal/kg.
8800
12000
5000
16000
✅ The correct answer is option A.
118. The ratio of maximum adiabatic flame temperature in air to that in pure oxygen is always
1
<1
> 1
Unpredicatable
✅ The correct answer is option B.
119. Coke ovens in steel plant are heated by
Electricity
Coke oven gas
Mixed gas
Both B & C
✅ The correct answer is option D.
120. Caking index of coal blend used for blast furnace coke making is about
8
12
22
36
✅ The correct answer is option C.