Fuels and Combustion MCQs

Question 1

Mineral matter, 'M' and ash percentage 'A' in coal are roughly related as

Accepted Answer

M = 1.1 A

Answer

M = 1.8 A

Answer

M = 0.5 A

Answer

M = A

Question 2

Percentage of hydrogen in coke oven gas may be around

Accepted Answer

60

Answer

10

Answer

25

Answer

45

Question 3

Percentage of methane in coke oven gas may be around

Accepted Answer

25

Answer

5

Answer

15

Answer

50

Question 4

In Lurgi coal gasifier,

Accepted Answer

Larger quantity of coal can be processed

Answer

Coking coals cannot be used

Answer

Low carbon conversion efficiency is achieved

Answer

Entrainment of solids is higher

Question 5

During coal carbonisation process, the conversion of semi-coke to coke is accompanied by an increase in the __________ of the mass.

Accepted Answer

Density

Answer

Porosity

Answer

Electrical resistivity

Answer

None of these

Question 6

__________ present in coal is not determined in its ultimate analysis.

Accepted Answer

Fixed carbon

Answer

Total carbon

Answer

Hydrogen

Answer

Nitrogen

Question 7

Prime coking coal is always blended with medium or non- coking coal before ear-bonisation

Accepted Answer

Both A & B

Answer

To check against its excessive swelling during heating, which may exert high pressure and damage coke oven walls

Answer

Because, it alone produces unreactive coke

Answer

Neither A nor B

Question 8

Which of the following is not a by-product fuel?

Accepted Answer

Petrol

Answer

Pitch

Answer

Blast furnace gas

Answer

Refinery gas

Question 9

Which of the following is the most reactive (as regards the formation of CO + H2 from C + H2O)?

Accepted Answer

Low temperature coke

Answer

Blast furnace coke

Answer

Anthracite coal

Answer

Sub-bituminous coal