Practice Test: Question Set - 12
1. Coke oven gas after passing through return electrostatic tar precipitator (RETP) is used for the
- (A) Hot scarfing of steel
slabs
- (B) Mixing with blast furnace gas
- (C) Coke oven battery heating
- (D) Steel ladle drying
2. High sulphur content in a fuel __________ of the flue gases.
- (A) Decreases the dew point
- (B) Increases the dew point
- (C) Reduces the combustion efficiency by limiting the permissible
temperature reduction
- (D) Both (b) and (c)
3. Water gas constitutes mainly of
- (A) CO & H2
- (B) CO & N2
- (C) CO2 & H2
- (D) CH4 & H2
4. Which of the following petrological constitutes is responsible for bright and lustrous black band of bituminous coal?
- (A) Vitrain
- (B) Clarain
- (C) Durain
- (D) Fussain
5. Efficient burning of anthracite coal requires
- (A) Low preheat of air
- (B) Fine grinding
- (C) High excess air
- (D) All (a), (b) and (c)
6. Which will have the least volatile matter and hence will be the most difficult to ignite?
- (A) Bituminous coal
- (B) Coke
- (C) Semi-bituminous coal
- (D) Anthracite
7. Washing of coal is done to reduce the
- (A) Inherent impurities
- (B) Adhering impurities
- (C) Mineral matter
- (D) Both (b) and (c)
8. Number of macrocomponents present in coal according to Stopes are:
- (A) Four
- (B) Five
- (C) Six
- (D) Two
9. Too much of excess air in combustion results in high
- (A) Fuel consumption for the same heat load
- (B) Stack gas temperature
- (C) Percentage of oxygen in flue gases
- (D) All (a), (b) and (c)
10. Weathering of coal during storage causes
- (A) Reduction in coal size
- (B) Increase in its friability
- (C) Decrease in its caking capacity
- (D) All (a), (b) and (c)
11. Coking time in narrow by-product coke ovens is around __________ hours.
- (A) 18
- (B) 48
- (C) 8
- (D) 80
12. The main function of primary air in pulverized coal fired burner is to
- (A) Burn CO to CO2
- (B) Dry and transport the coal
- (C) Have proper combustion by supplying it around the burner
- (D) Preheat the tertiary air used for complete combustion of CO to CO2
13. Which of the following is a primary fuel?
- (A) Blast furnace coke
- (B) Gasoline
- (C) Natural gas
- (D) Wood charcoal
14. Which of the following has the highest calorific value (kcal/Nm3)?
- (A) Carbureted water gas
- (B) Gobar (cow dung) gas
- (C) Natural gas
- (D) LPG
15. Hard coke is manufactured from
- (A) Lignite
- (B) Bituminous coal
- (C) Semi-anthracite
- (D) Anthracite
Next Tests: