121. Natural draft created by the chimney depends upon
Temperature of the flue gas
Its height
Both A & B
Neither A nor B
✅ The correct answer is option C.
Fuel and Combustion MCQs
122. In low temperature carbonisation of coal as compared to high temperature carbonisation __________ produced is less.
Difference in gross & net calorific value of the coke oven gas
Free carbon content in tar
Yield percentage of coke
Yield of ammonia present in coke oven gas
✅ The correct answer is option A.
123. High sulphur (4-6%) coal in India are found in
Assam
Andhra Pradesh
Bengal
Madhya Pradesh
✅ The correct answer is option A.
124. Sometimes water is sprayed during coal charging in the coke oven, which helps in
Prevention of clinker formation in the oven
Controlling the dust nuisance while charging the coal
Reducing the cracking of hydrocarbons in the gas and increasing the percentage of CO & H₂ in the gas (due to the endothermic reaction represented by C + H₂O = CO + H₂)
All of the above
✅ The correct answer is option D.
125. Gross & net calorific value is the same for
Blast furnace gas
Coke oven gas
L.D. converter gas
None of these
✅ The correct answer is option C.
126. Power alcohol as compared to straight run gasoline has lower
Calorific value
Octane number
Specific gravity
Viscosity
✅ The correct answer is option A.
127. High rate of heating of coke ovens
May damage its walls due to abrupt excessive swelling of coal
Produces larger size coke
Increases the time of carbonisation
None of these
✅ The correct answer is option A.
128. Heat penetration rate in narrow coke ovens in high temperature carbonisation of coal is around __________ cm/hr.
2.5
0.5
10
20
✅ The correct answer is option A.
129. Calorific value of both the solid & liquid fuels can be determined by using __________ calorimeter.
Junker’s
Bomb
Boy’s
None of these
✅ The correct answer is option B.
130. The gasification reaction represented by, C + H₂O = CO + H₂, is
Exothermic
Endothermic
Catalytic
Autocatalytic
✅ The correct answer is option B.