As the C/H ratio of the fuel increases, the amount of CO2 formed on combustion _______________ for the same percentage of excess air?

Related Mcqs:

1. The optimum percentage of excess air for combustion depends upon the _______________ of the fuel?

   A. Type (solid, liquid or gaseous)
   B. Calorific value
   C. Sulphur content
   D. Ignition temperature

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

   A. Increase
   B. Decrease
   C. Increase or decrease depending on the fuel type
   D. Not change

3. Use of excess of combustion air in the combustion of fuels results in__________________?

   A. Heat losses
   B. Long flame
   C. Condensation of water vapour from the fuel gas
   D. None of these

4. With increase in C/H ratio of a fuel, the amount of CO2 formed on its complete combustion____________________?

   A. Increases
   B. Decreases
   C. Remain same
   D. Either A. or B., depends on other factors

5. For every 10% increase in the excess air; the fuel consumption increases by _______________ percent?

   A. 0.1
   B. 0.2
   C. 0.5
   D. 1.0

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. The main drawback of supplying more excess air in the combustion of fuel is the_________________?

   A. Excessive power requirement of air blower
   B. Enhanced sensible heat loss in the flue gas
   C. Intermittent and uncontrolled combustion of the fuel
   D. High exit flue gas temperature from the furnace

8. Supply of excess air for complete combustion of fuel is necessitated to facilitate___________________?

   A. Its thorough mixing with air
   B. Attainment of chemical equilibrium
   C. Attainment of high temperature
   D. None of these

9. Which of the following would require maximum amount of % excess air for complete combustion ?

   A. Coke oven gas
   B. Furnace oil
   C. Pulverised coal
   D. Lump coal (fixed on chain grate)

10. Use of preheated air for combustion of fuel in the furnace, increases the___________________?

    A. Scale losses of the furnace stock
    B. Calorific value of the fuel
    C. Flame temperature
    D. None of these