Q.1

Bulk density of pulverised coal may be about __________ kg/m3.

  • 100
  • 500
  • 1000
  • 1500
Q.2

A fuel with high heat release rate will

  • require smaller combustion chamber.
  • have high calorific value.
  • have high adiabatic flame temperature.
  • none of these.
Q.3

High pressure coal gasification is employed in __________ process.

  • Lurgi
  • Kopper-Totzek
  • Winkler
  • none of these
Q.4

Coke ovens in steel plant are heated by

  • electricity
  • coke oven gas
  • mixed gas
  • both(b) & (c)
Q.5

Which of the following is the most important deterrents to an extended use of pulverised coal in boiler firing ?

  • Ash disposal problem.
  • Excessive fly-ash discharge from the stack.
  • High power consumption in its transportation.
  • Erosion of induced draft fan blades.
Q.6

Incomplete combustion of fuel in the furnace is judged by high __________ of the flue gases.

  • CO content
  • dew point
  • CO2 content
  • O2 content
Q.7

When steam is passed over coal resulting in the endothermic reaction represent by, C + H2O = CO + H2, it is called the __________ of coal.

  • carbonisation
  • oxidation
  • coalification
  • gasification
Q.8

KOH solution used in orsat apparatus absorbs

  • CO2
  • SO2
  • both (a) & (b)
  • neither (a) nor (b)
Q.9

Coke oven gas is stripped of its H2S and mercaptans content by

  • absorption in wash oil.
  • adsorption on bog iron bed.
  • bubbling it through dilute sulphuric acid.
  • adsorption on silica gel.
Q.10

In Lurgi coal gasifier,

  • coking coals cannot be used.
  • low carbon conversion efficiency is achieved.
  • entrainment of solids is higher.
  • larger quantity of coal can be processed.
Q.11

The calorific value of a gas of composition CO2 = 20%, H2 = 50%, CH4 = 30%, is y. If the composition of gas is changed to H2 = 50%, CH4 = 30%, CO2 = 10%, N2 = 10%, then the calorifice value will be

  • y
  • 0.95 y
  • 1.05 y
  • 1.8 y
Q.12

The lowest temperature, at which a solid fuel produces enough vapors to support continuous combustion, is called

  • fire point
  • smoke point
  • burning temperature
  • kindling temperature
Q.13

Deficiency of combustion air during combustion of a gaseous fuel

  • lengthens the flame.
  • causes heat loss of fuel by its partial combustion.
  • both (a) & (b).
  • shortens the flame.
Q.14

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

  • Pitch
  • Blast furnace gas
  • Petrol
  • Refinery gas
Q.15

Blast furnace coke is made from coal by

  • low temperature carbonisation.
  • high temperature carbonisation.
  • medium temperature carbonisation.
  • heating the coal in an oven in presence of air.
Q.16

A travelling grate stoker is meant for the efficient burning of __________ coal.

  • caking
  • pulverised
  • non-caking
  • high ash
Q.17

Gas yield in the Kopper-Totzek coal gasifier is about __________ Nm3/ton coal (ash = 35%).

  • 150
  • 1500
  • 3500
  • 5000
Q.18

Calorific value of dry wood may be around __________ Kcal/kg.

  • 5
  • 50
  • 500
  • 5000
Q.19

Coke oven gas constitutes mainly of

  • H2 & CO
  • H2 & CH4
  • CH4 & CO
  • H2 & CO2
Q.20

'Fuel' can be defined as a substance which produces heat by

  • combustion.
  • nuclear fission.
  • nuclear fusion.
  • all (a), (b) & (c).
Q.21

Flue gas from the heating chamber of byproduct coke ovens is removed by

  • forced draft fan
  • induced draft fan
  • steam ejector
  • natural draft
Q.22

Coke oven gas is a better fuel than blast furnace gas, because of its higher

  • calorific value, cleanliness and relatively low distribution cost (due to its low specific gravity).
  • adiabatic flame temperature.
  • heat release rate (thus requiring smaller combustion chamber).
  • all (a), (b) and (c).
Q.23

Calorific value of both the solid & liquid fuels can be determined by using __________ calorimeter.

  • Junker's
  • Bomb
  • Boy's
  • none of these
Q.24

Which of the following has the highest theoretical flame temperature ?

  • Blast furnace gas
  • Hydrogen
  • Acetylene
  • Coke oven gas
Q.25

Dry air requirement for burning 1 Nm3 of CO to CO2 may be around __________ Nm3.

  • 2.4
  • 1.75
  • 0.87
  • 11.4
Q.26

For which pair of the fuel gases, calorific value (C.V.) of one fuel is almost double that of the other on volume basis (i.e., kcal/Nm3 ), while the C.V. is same on weight basis (i.e., kcal/kg) ?

  • Propane and acetylene
  • Propane and LPG
  • Sewage gas and gobar gas
  • B.F. gas and coke oven gas
Q.27

One kg of carbon for theoretically complete combustion requires __________ kg of air.

  • 11.5
  • 0.5
  • 23
  • 12
Q.28

Gray-King Assay and Roga Index of coal is a measure of its

  • abradability.
  • grindability.
  • weathering properties.
  • caking and swelling properties.
Q.29

A coal having high volatile matter content will

  • give less yield of tar and gas on carbonisation.
  • burn with a small non-smoky flame.
  • have a very high calorific value.
  • none of these.
Q.30

Traces of tar fog present in the coke oven gas is removed by

  • cyclone separator.
  • wet packed scrubber.
  • electrostatic precipitator.
  • washing with monoethanolamine.
Q.31

Which of the following fuels is the best for burning on chain grate stoker ?

  • Non-caking coal
  • Caking coal
  • Coking coal
  • Pulverised coal.
Q.32

Froth floatation is used for

  • washing fine coal dust (< 0.5 mm size).
  • washing lump coal (> 80 mm size).
  • removing ash from the coal based on difference in specific gravity of coal and ash.
  • all (a), (b)and(c).
Q.33

Preheating of combustion air is done to

  • increase the adiabatic flame temperature.
  • increase the calorific value of the fuel.
  • complete the combustion of fuel.
  • reduce its requirement for effecting the complete combustion.
Q.34

Gross heating value of coal is __________ the net heating value.

  • higher than
  • lower than
  • same as
  • either (a) or (b); depends on the type of coal
Q.35

Yield of blast furnace gas is about __________ Nm3 /ton of pig iron.

  • 300
  • 2000
  • 5000
  • 10000
Q.36

Pick out the wrong statement.

  • Angle of repose of coal increases with its increasing size.
  • Specific gravity of coal increases with its increasing maturity.
  • Refractive index and reflectance of coal increases with the increasing rank of coal.
  • Specific heat of coal decreases with increases in the volatile matter and decrease in the C/H ratio of coal.
Q.37

Calorific value of gobar gas (containing CH4 =, H2 = ; CO2 = 30%) may be about __________ Kcal/Nm3.

  • 1800
  • 3200
  • 5400
  • 10200
Q.38

Gross heating value of coal is __________ the net heating value.

  • higher than
  • lower than
  • same as
  • none of these
Q.39

Which of the following is a rich fuel gas ?

  • Producer gas.
  • Coal gas from underground gasification of coal.
  • Refinery gases.
  • None of these.
Q.40

Washing of coal

  • reduces its sulphur and ash content.
  • controls its ash fusibility and increases its calorific value.
  • improves its coking properties.
  • all (a), (b) and (c).
Q.41

Short/intense flame is produced during combustion of gaseous fuel by using

  • high amount/current of combustion air.
  • low amount/current of combustion air.
  • preheated secondary air.
  • very little excess air.
Q.42

Coke oven gas produced by high temperature carbonisation of coal (as compared to that produced by low temperature carbonisation), has

  • higher calorific value.
  • lower hydrogen content.
  • both (a) and (b).
  • neither (a) nor (b).
Q.43

Ultimate analysis of coal determines its __________ content.

  • carbon, hydrogen, nitrogen & sulphur.
  • carbon, ash, sulphur & nitrogen.
  • carbon, sulphur, volatile matter & ash.
  • carbon, volatile matter, ash & moisture.
Q.44

(64-rank coal (ASTM) means a coal with 64%

  • fixed carbon and having a heating value around 13, 200 BTU/1b.
  • ash and heating value around 13, 200 BTU/1b.
  • fixed carbon and heating value around 132 BTU/1b.
  • none of these.
Q.45

Degree of carbonisation of coal during coke making can be roughly judged by the __________ of the coke produced.

  • colour
  • moisture content
  • ash content
  • volatile matter
Q.46

Ash content in the coke produced from a coking coal havingash may be around __________ percent.

  • 6
  • 12
  • 18
  • 24
Q.47

In low temperature carbonisation of coal, the

  • yield of coke oven gas is 290 Nm3 /ton dry coal.
  • volatile matter in coke is zero.
  • temperature maintained is 700°C.
  • yield of tar is about 3% of dry coal.
Q.48

Which of the following fuel gases will require maximum amount of air for combustion of 1 Nm3 gas ?

  • Blast furnace gas
  • Natural gas
  • Producer gas
  • Water gas
Q.49

Percentage of nitrogen in blast furnace gas may be around

  • 5
  • 25
  • 55
  • 80
Q.50

If CO2 is not fully absorbed by the KOH solution meant for its absorption in the orsat apparatus, it will appear as

  • O2
  • CO
  • N2
  • SO2
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