211. Blast furnace gas burns with a bluish flame, because of the presence of
CO
CH₄
CO₂
S
✅ The correct answer is option A.
Fuel and Combustion MCQs
212. A coal having high ratio of volatile matter to fixed carbon as compared to a coal having low ratio of volatile matter to fixed carbon
Is less liable to spontaneous combustion on storage
Is more difficult to ignite and produces a shorter flame
Requires smaller combustion space and less secondary air
None of these
✅ The correct answer is option D.
213. Gobar gas is produced by the __________ of ‘gobar’ (cow dung).
Hydrolysis
Fermentation
Oxidation
Dehydration
✅ The correct answer is option B.
214. Removal of hydrogen from coke oven gas
Increases its calorific value
Decreases its calorific value
Does not alter its calorific value
Is not possible on commerical scale
✅ The correct answer is option A.
215. Coking time in narrow by-product coke ovens is around __________ hours.
18
48
8
80
✅ The correct answer is option A.
216. Which of the following can be made into briquettes without the use of a binder?
Lignite
Bituminous coal
Anthracite coal
None of these
✅ The correct answer is option A.
217. White flue gas (resembling steam) coming out of the chimney of a thermal power plant indicates that the fuel used in the boiler furnace is
Tar
Coke oven gas
Pitch
Pulverised coke
✅ The correct answer is option B.
218. Number of macrocomponents present in coal according to Stopes are
Four
Five
Six
Two
✅ The correct answer is option A.
219. Which of the following fuels is generally not used in thermal power plant boiler firing?
Furnace oil, light diesel oil and tar/PCM
Pulverised coking coal
Coal middling from washeries
B.F. gas, coke oven gas and L.converter gas
✅ The correct answer is option B.
220. Which of the following will generate maximum volume of product of complete combustion (Nm³/Nm³ of fuel) ?
Carburetted water gas
Blast furnace gas
Natural gas
Producers
✅ The correct answer is option C.