Fuels and Combustion

151.Fischer-Tropsch method aims at the

1. Gasification of coal
2. Synthesis of gasoline (from water gas)
3. Hydrogenation of coal to produce gasoline
4. None of these

View answer

152.Fixed carbon in coal is defined as

1. That present in volatile matters
2. The total quantity of carbon present in the coal
3. Hundred minus the percentage of volatile matter, ash and moisture
4. The one which is present in the residue after combustion

View answer

153.Flue gas discharge velocity through chimney of a big thermal power plant may be around _________ m/sec.

1. 0.5
2. 10
3. 50
4. 500

View answer

154.Flue gas from the heating chamber of byproduct coke ovens is removed by

1. Forced draft fan
2. Induced draft fan
3. Steam ejector
4. Natural draft

View answer

155.Flue gas obtained on complete combustion of pure acetylene (a hydrocarbon fuel) will contain

1. CO
2. CO₂
3. H₂O
4. Both (B) & (C)

View answer

156.For every 10% increase in the excess air; the fuel consumption increases by _________ percent.

1. 0.1
2. 0.2
3. 0.5
4. 1

View answer

157.For long flame and easy ignition, the coal used should have

1. High volatile matter
2. Low ash
3. High calorific value
4. High ash

View answer

158.For maximum discharge through a chimney, its height should be

1. 200 meters
2. Infinitely long
3. More than 105.7 metres
4. Equal to the height of the hot gas column producing draught

View answer

159.For the case of a fuel gas undergoing combustion with air, if the air/fuel ratio is increased, the adiabatic flame temperature will

1. Increase
2. Decrease
3. Increase or decrease depending on the fuel type
4. Not change

View answer

160.For which pair of the fuel gases, calorific value (C.V.) of one fuel is almost double that of the other on volume basis (i.e., kcal/Nm³), while the C.V. is same on weight basis (i.e., kcal/kg)?

1. Propane and acetylene
2. Propane and LPG
3. Sewage gas and gobar gas
4. B.F. gas and coke oven gas

View answer