Q.1

Cannel coal and boghead coal are the examples of

  • humic coals
  • liptobiolites
  • sapropelic coals
  • none of these
Q.2

Presence of free moisture in coal is most disadvantageous during

  • its pulverisation (as it requires more power).
  • combustion of fire slacks on the grates.
  • handling (e.g. when emptying wagons).
  • none of these.
Q.3

A fuel containing carbon and carbon monoxide (but containing no hydrogen or its compounds) is burnt in pure oxygen at constant pressure. Its gross calorific value as compared to net calorific value will be

  • more
  • less
  • same
  • data insufficient; can't be predicted.
Q.4

Yield of pitch from distillation of high temperature tar is around __________ percent.

  • 10
  • 25
  • 65
  • 90
Q.5

Which of the following will be unsuitable for dust cleaning from flue gas at 400°C from a pulverised coal fired boiler ?

  • Multicyclones
  • Bag filter
  • Wet scrubber
  • Hydrocyclones.
Q.6

Which of the following has the highest flame velocity ?

  • H2
  • CO
  • CH4
  • C2H6
Q.7

The gasification reaction represented by, C + H2O = CO + H2, is

  • exothermic
  • endothermic
  • catalytic
  • autocatalytic
Q.8

Ignition temperature decreases progressively from anthracite to lignite, because

  • volatile matter content increases.
  • carbon content decreases.
  • moisture content increases.
  • ash content increases.
Q.9

Anthracite can be used for

  • recarbonising steel.
  • making carbon electrodes;
  • blending with highly coking coal to check its swelling which helps in saving coke even walls from damage and to produce high strength coke.
  • all (a), (b) and (c).
Q.10

Which of the following combustibles is absent in blast furnace gas ?

  • H2
  • CH4
  • CO
  • none of these
Q.11

The heat of combustion of a fuel

  • is equal to the heat of formation.
  • is always negative.
  • can't be known without calculating it.
  • is always positive.
Q.12

Presence of phosphorous in metallurgical coal

  • is not undersirable.
  • reduces its calorific value.
  • badly affects the quality of steel.
  • increases its caking power.
Q.13

Initial pressure of oxygen introduced into the 'bomb' of the bomb calorimeter for determination of calorific value of coal/fuel oil may be around __________ atm.

  • 95-100
  • 3-5
  • 25-30
  • 60-65
Q.14

Fuel consumption in coke making can be reduced by

  • preheating, blending and de-ashing the coal.
  • stamped charging of coal.
  • dry quenching of coke.
  • all (a), (b) and (c).
Q.15

Emission of dense white smoke out of the chimney of a thermal power plant is an indication of the use of

  • less air for combustion.
  • correct amount of air for combustion.
  • too much air for combustion.
  • pulverised coal in boilers.
Q.16

Which of the following constituents of a fuel does not contribute to its calorific value on combustion ?

  • Hydrogen
  • Sulphur
  • Carbon
  • None of these
Q.17

Insitu theory and drift theory are related to the

  • origin of petroleum oil.
  • origin of coal.
  • coalification.
  • variation of coal quality with depth.
Q.18

Which of the following fuel gases is heavier than air ?

  • Blast furnace gas
  • Coke oven gas
  • Natural gas
  • Water gas
Q.19

The calorific value of producer gas is around __________ kcal/Nm3

  • 1300
  • 500
  • 4500
  • 9000
Q.20

High excess air in combustion of fuels results in

  • increased fuel consumption
  • incomplete combustion
  • smoky flame
  • none of these
Q.21

'Fat' coal means a coal having

  • low calorific value.
  • high volatile matter,
  • low ash content.
  • non smoking tendency.
Q.22

During combustion of coal on grate, clinker formation is increased by the

  • use of thick fire bed.
  • low fusion point of ash (< 1100° C).
  • use of preheated primary air.
  • all (a), (b) & (c).
Q.23

Pick out the wrong statement.:

  • Carburetted water gas is also called blue gas.
  • Coals are divided in four species according to their carbon content in Seylor's classification.
  • Carbonisation time in a by-product coke oven is about 16 hours.
  • Gross and net calorific value of a fuel is the same, if it does not contain hydrogen or hydrocarbons.
Q.24

Lurgi gasifier (high pressure gasifier) as compared to Kopper Totzek gasifier (atmospheric pressure gasifier) produces

  • higher amount of methane.
  • lower amount of hydrogen.
  • both (a) and (b).
  • higher amount of both methane and hydrogen.
Q.25

Pick out the wrong statement.

  • Indian coals on an average contain 25-30% ash as against 10-12% ash in imported coking coal.
  • Ammonia is recovered in the form of ammonium sulphate in direct process of by-product recovery.
  • A high swelling index number of coking coal indicates poor caking properties of coal.
  • Wash oil is used for scrubbing benzol from coke oven gas.
Q.26

Correct viscosity of furnace oil at the burner tip for proper atomisation is aboutcentistokes. To reduce the viscosity of high viscosity furnace oil (centistokes) to the correct atomisation viscosity (i.e.cst), it should be preheated to about____°C.

  • 70
  • 85
  • 105
  • 145
Q.27

About __________ Nm3 of air will be required for the complete combustion of 2Nm3 of CO.

  • 2
  • 3
  • 5
  • 1
Q.28

Abrasion index of blast furnace coke should be around __________ percent.

  • 20
  • 35
  • 55
  • 80
Q.29

If the specific heat of gaseous products of combustion of a fuel is high, the abiabatic flame temperature will be

  • low
  • high
  • very high, if the fuel is of low calorific value
  • none of these
Q.30

A good metallurgical coke should have very low

  • sulphur & phosphorous content
  • porosity
  • fusion point of its ash
  • hardness & strength
Q.31

For long flame and easy ignition, the coal used should have

  • high volatile matter
  • low ash
  • high calorific value
  • high ash
Q.32

Heat penetration rate in narrow coke ovens in high temperature carbonisation of coal is around __________ cm/hr.

  • 2.5
  • 0.5
  • 10
  • 20
Q.33

Theoretical flame temperature of a fuel is that temperature which is attained, when the fuel is completely burnt 'using theoretical amount of air in

  • air
  • oxygen
  • either (a) or (b)
  • either (a) or (b) without gain or loss of heat
Q.34

Coking time in beehive coke oven is about

  • 12 hours
  • 2-3 days
  • one week
  • two weeks
Q.35

Tar yield in the low temperature and high temperature carbonisation of dry coal may be respectively __________ percent.

  • 3 & 10
  • 10 & 3
  • 10 & 20
  • 15 & 8
Q.36

Cannel coal

  • is non-coking.
  • has a high volatile matter content and burns with a luminous smoky flame.
  • is a non-banded coal which can be ignited easily with a match stick or candle flame, hence is so named.
  • all (a), (b) and (c).
Q.37

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

  • Carburetted water gas
  • Gobar gas
  • Natural gas
  • LPG
Q.38

Which of the following will generate maximum volume of product of complete combustion (Nm3/Nm3 of fuel) ?

  • Carburetted water gas
  • Blast furnace gas
  • Natural gas
  • Producers' gas
Q.39

Use of preheated air for combustion of fuel in the furnace, increases the

  • scale losses of the furnace stock.
  • calorific value of the fuel.
  • flame temperature.
  • none of these.
Q.40

Fixed carbon in coal is defined as

  • that present in volatile matters.
  • the total quantity of carbon present in the coal.
  • hundred minus the percentage of volatile matter, ash and moisture.
  • the one which is present in the residue after combustion.
Q.41

Bomb calorimeter can be used to determine the __________ of the coal.

  • sulphur content
  • calorific value
  • both(a) & (b)
  • neither (a) nor (b)
Q.42

Most of the coking coals are

  • anthracite
  • bituminous
  • lignite
  • none of these
Q.43

Washing of coal

  • reduces its ash & sulphur content.
  • improves its coking properties.
  • increase the fusion point of its ash by removing chlorine compounds.
  • all (a), (b) and (c).
Q.44

Pulverised coal used in boiler firing need not have

  • less moisture content
  • high fusion point of its ash
  • high bulk density
  • lower ash content
Q.45

Which of the following is a poisonous fuel gas?

  • Coke oven gas
  • Blast furnace gas
  • Natural gas
  • None of these
Q.46

Gobar gas constitutes mainly of

  • CH4 & CO2
  • CO & CO2
  • CH4 & N2
  • CO & N2
Q.47

During coking of coal, the ash content (percentage)

  • increases
  • decreases
  • remains constant
  • -
Q.48

C/H ratio is the maximum in case of

  • coal
  • furnace oil
  • natural gas
  • naphtha
Q.49

Which of the following petrological constitutes is responsible for bright and lustrous black band of bituminous coal ?

  • Vitrain
  • Clarain
  • Durain
  • Fussain
Q.50

Calorific value of of blast furnace gas is around __________ KCal/Nm3.

  • 850
  • 1800
  • 4200
  • 6500
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