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.

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

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

Number of macrocomponents present in coal according to Stopes are ___________________?

A. Four
B. Five
C. Six
D. Two

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.

The main function of primary air in pulverised 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

Which of the following has the highest calorific value (kcal/Nm3) ?

A. Carburetted water gas
B. Gobar gas
C. Natural gas
D. LPG

Blast furnace gas compared to coke oven gas has_________________?

A. Lower ignition temperature
B. Narrower limit of inflammability
C. Higher calorific value
D. Lower theoretical flame temperature

Which of the following is a poisonous fuel gas ?

A. Coke oven gas
B. Blast furnace gas
C. Natural gas
D. None of these

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