If oxygen content in the flue gas rises too high, fuel is being wasted by _______________?

Related Mcqs:

1. Pure carbon is completely burnt in oxygen. The flue gas analysis is 70%CO2, 20%CO and 10%O2. The percent excess oxygen used is __________________?

   A. 20
   B. 12.5
   C. 0
   D. 10

2. Incomplete combustion of a fuel is characterised by the high _______________ in the flue gas?

   A. Smoke
   B. Temperature
   C. Oxygen
   D. Carbon monoxide

3. Oxygen content in a flue gas was found to be 4%. It implies that excess air used for combustion was around ______________ percent?

   A. 4
   B. 96
   C. 20
   D. 40

4. 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.

5. Explosion limit of blast furnace gas is 37 to 71% gas in gas-air mixture. It means that the blast furnace gas will explode when burnt in a confined space, if its concentration in the gas-air mixture is _______________ percent?

   A. 71%
   C. In between 37 & 71%
   D. None of these

6. A liquid/gaseous fuel containing hydrocarbons and high amount of sulphur is burnt with 40% excess air. The flue gas still contains large amount of carbon monoxide. This may be due to the_________________?

   A. Presence of large quantity of hydrogen in the fuel
   B. Low calorific value of the fuel
   C. High sulphur content in the fuel
   D. Lack of thorough mixing of fuel with air

7. 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?

   A. 400-500
   B. 900-1000
   C. 1400-1500
   D. 1700-1800

8. Blast furnace gas is a very poisonous gas because of its predominantly high _______________ content?

   A. H2O
   B. CO2
   C. CO
   D. CH4

9. In flue gas analysis by Orsat’s apparatus, oxygen is absorbed by____________________?

   A. Potassium hydroxide
   B. Cuprous chloride
   C. Alkaline pyrogallol solution
   D. None of these

10. 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_______?

    A. Tar
    B. Sulphide Coke
    C. Coke Oven Gas
    D. Pulverised coke

    Submitted by: Muhammad Mutsadiq Umer