221. Low temperature oxidation of coal resulting from bad storage conditions does not decrease its
Caking power
Calorific value
Hydrogen content
Oxygen content
✅ The correct answer is option D.
Fuel and Combustion MCQs
222. __________ is used as jet engine fuel.
Petrol
Diesel
Kerosene
LPG
✅ The correct answer is option C.
223. (64-132) rank coal (ASTM) means a coal with 64%
Fixed carbon and having a heating value around 13, 200 BTU/1b
Ash and heating value around 13, 200 BTU/1b
Fixed carbon and heating value around 132 BTU/1b
None of these
✅ The correct answer is option A.
224. ‘Mixed gas’ used in steel plants is a mixture of
B.F. gas and coke oven gas
Coke oven gas and converter gas
Coke oven gas and L.P.G
Blast furnace gas and naphtha vapor
✅ The correct answer is option A.
225. With increase in the oxygen content of the coal, its __________ decreases.
Calorific value
Caking power
Both A & B
Neither A nor B
✅ The correct answer is option C.
226. Gasification of the solid fuel converts its organic part into combustible by interaction with air/oxygen and steam so as to obtain a secondary gaseous fuel of high calorific value having no ash. Gasification reactions are normally carried out at about __________ °C.
400-500
900-1000
1400-1500
1700-1800
✅ The correct answer is option B.
227. Nitrogen present in the flue gas is determined in the orsat apparatus by absorbing it in
KOH
Ammoniacal cuprous chloride
Pyrogallol solution
None of these
✅ The correct answer is option D.
228. Ionisation potential applied across the electrodes of electrostatic tar precipitator is around
230 V AC
60 KV AC
230 V DC
60 KV DC
✅ The correct answer is option D.
229. Gross heating value of coal is __________ the net heating value.
Higher than
Lower than
Same as
None of these
✅ The correct answer is option A.
230. Preheating of combustion air is done to
Increase the adiabatic flame temperature
Increase the calorific value of the fuel
Complete the combustion of fuel
Reduce its requirement for effecting the complete combustion
✅ The correct answer is option A.