131. C/H ratio is the maximum in case of
Coal
Furnace oil
Natural gas
Naphtha
✅ The correct answer is option A.
Fuel and Combustion MCQs
132. Which of the following petrographic constituents of coal is non-coking?
Vitrain
Clarain
Durain
Fussain
✅ The correct answer is option D.
133. Desirable “Micum Index” values of metal-lurical coke are
M40 > 78% and M10 < 10%
M40 > 4% and M10 < 80%
M40 > 10% and M10 < 78%
M40 > 98% and M10 < 2%
✅ The correct answer is option A.
134. The maximum percentage of CO₂ in a flue gas (from a carbonaceous fuel) can be
21
77
79
29
✅ The correct answer is option A.
135. The advantage of firing pulverised coal in the furnace lies in the fact, that it
Permits the use of high ash content coal
Permits the use of low fusion point ash coal
Accelerates the burning rate and economises on fuel combustion
All of the above
✅ The correct answer is option C.
136. A good metallurgical coke should have very low
Sulphur & phosphorous content
Porosity
Fusion point of its ash
Hardness & strength
✅ The correct answer is option A.
137. As the equilibrium moisture content of the coal increases, its
Calorific value increases
Swelling number decreases
Swelling number increases
Bulk density decreases
✅ The correct answer is option B.
138. Preheating of __________ the flame temperature.
The gaseous fuel before combustion decreases
Combustion air decreases
Either the fuel or the air or both, increases
Either the fuel or the air does not affect
✅ The correct answer is option C.
139. __________ process is meant for direct hydrogenation of coal to produce liquid fuel.
Fischer-Tropsch
Bergius
Lurgi
None of these
✅ The correct answer is option B.
140. Low temperature carbonisation of coal produces
Metallurgical coke
Soft coke
Very low calorific value coke oven gas
No by-products
✅ The correct answer is option B.