Fuels and Combustion MCQs

A. More
B. Less
C. Equal
D. More or less; (depends on the state of fuel.)

A. Higher than
B. Lower than
C. Same as
D. None of these

A. Coke oven gas yield is more
B. Tar yield is less but free carbon in tar is more
C. Calorific value of coke oven gas is less
D. All a., b. and c.

A. Lignite
B. Bituminous coal
C. Anthracite
D. High temperature coke (v.m < 0.5%)

A. Reduces its consumption in the furnace
B. Increases its consumption in the furnace
C. Does not affect its consumption in the furnace
D. Decreases its hardness and abrasion resistance

A. Low reactivity of carbonised residue containing high proportions of iron & sulphur
B. Low forced draught and fuel bed temperature
C. Thick fire bed and preheated primary air
D. All a., b. and c.

A. Coke oven gas
B. Producer gas
C. Blast furnace gas
D. L.d. converter gas

A. It is abrasive to the coal pulveriser (i.e. ball mill) and the combustion chamber
B. The ash in molten condition gets absorbed in the pores of the refractory lining of the furnace
And causes its spalling due to different co-efficient of expansion/contraction of the refractory
And the ash

A. 10
B. 25
C. 45
D. 60

A. Produced by low temperature carbonisation of coal
B. A domestic fuel
C. Used in blast furnaces
D. None of these