Q.1

Which adsorbant is used for removing sulphur compounds (S Q, H2S, RSH etc.) removal from coke oven gas in by-products recovery plant ?

  • Silica gel
  • Diatomaceous earth
  • Basalt
  • Bog iron (i.e., moist ferric hydroxide)
Q.2

When the coal is heated in absence of air, it is called its

  • deoxidation
  • gasification
  • coalification
  • carbonisation
Q.3

The maximum percentage of CO2 in a flue gas (from a carbonaceous fuel) can be

  • 21
  • 77
  • 79
  • 29
Q.4

A good quality coal should have

  • low fusion point of ash
  • high ash content
  • high sulphur
  • none of these
Q.5

Pure carbon is completely burnt in oxygen. The flue gas analysis is 70%CO2, 20%CO and 10%O2. The percent excess oxygen used is

  • 20
  • 12.5
  • 0
  • 10
Q.6

Oxygen percentage (by weight) in atmospheric air is

  • 19
  • 21
  • 23
  • 29
Q.7

With increase in C/H ratio of a fuel, the amount of CO2 formed on its complete combustion

  • increases
  • decreases
  • remains same
  • either (a) or (b), depends on other factors
Q.8

Low temperature oxidation of coal is accelerated by the

  • storage in large heaps.
  • storage in compressed piles.
  • absence of porous or friable particles.
  • all (a), (b) and (c).
Q.9

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

  • Fixed carbon
  • Total carbon
  • Hydrogen
  • Nitrogen.
Q.10

Orsat apparatus

  • gives flue gas analysis on dry basis.
  • determines N2 in flue gas indirectly.
  • can't determine CO in flue gas, if it is < 0.2%.
  • all (a), (b) & (c).
Q.11

The calorific value of 'LPG' (propane +butane) is about __________ kcal/Nm3.

  • 5000
  • 25, 000
  • 10, 000
  • 15, 000
Q.12

A particular coal is said to be free burning when it

  • burns completely.
  • gives smokeless burning.
  • shows little or no fusing action.
  • none of these.
Q.13

A good quality coal should have

  • low fusion point of ash
  • high ash content
  • high sulphur
  • none of these
Q.14

Hardgrove grindability index of four coal samples are given below. Which of them is the easiest to grind ?

  • 50
  • 70
  • 85
  • 100
Q.15

Tolerable concentration of toxic carbon monoxide in atmospheric air is about __________ PPm.

  • 50
  • 1000
  • 5000
  • 10000
Q.16

Rate of low temperature oxidation of coal due to bad storage conditions

  • decreases with increase in surface area.
  • does not vary with increase in surface area.
  • is more for low volatile coal compared to high volatile coal.
  • is accelerated by storage in large heaps with small surface to volume ratio.
Q.17

The ratio of maximum adiabatic flame temperature in air to that in pure oxygen is always

  • 1
  • <1
  • > 1
  • unpredicatable
Q.18

During the carbonisation of coal

  • all tar is evolved at < 600°C.
  • evolution of H2 and formation of methane and aromatics occur at > 700°C.
  • hard semi-coke starts shrinking at 600°C.
  • all (a), (b) and (c).
Q.19

Temperature of coke oven gas just before entering into saturator (for recovery of NH3) is about __________ °C.

  • 30
  • 65
  • 120
  • 180
Q.20

For everyincrease in the excess air; the fuel consumption increases by __________ percent.

  • 0.1
  • 2
  • 5
  • 10
Q.21

C.V. (kcal/Nm3) of gaseous fuels __________ with increase in molecular weight.

  • decreases
  • increases
  • remains constant
  • may increase or decrease, depends on combustibles.
Q.22

Shatter index of the coke is a measure of its

  • strength
  • bulk density
  • reactivity
  • none of these
Q.23

High amount of sulphur and phosphorous in coke causes

  • decrease in its calorific value.
  • increase in its strength.
  • brittleness of steel made by using it.
  • none of these.
Q.24

__________ of the coal is the basis for Seylor's coal classification.

  • Proximate analysis
  • Ultimate analysis
  • Caking index
  • Calorific value
Q.25

Which of the following is the maximum coal producing state in India ?

  • Orissa
  • West Bengal
  • Jharkhand
  • Assam
Q.26

The calorific value of L.D. converter gas is about __________ Kcal/Nm3 .

  • 1800
  • 800
  • 4500
  • 10000
Q.27

In flue gas analysis by Orsat's apparatus, carbon dioxide is absorbed by

  • potassium hydroxide.
  • dilute potassium carbonate.
  • cuporus chloride.
  • alkaline pyragllol solution.
Q.28

Washing of coal decreases its

  • caking index.
  • mineral matter content.
  • ash content.
  • both (b) and (c).
Q.29

Gobar gas is produced by the __________ of 'gobar' (cow dung).

  • hydrolysis
  • fermentation
  • oxidation
  • dehydration
Q.30

Which is the heaviest fuel gas out of the following ?

  • Blast furnace gas
  • Coke oven gas
  • Water gas
  • Carburetted water gas
Q.31

Pick the odd man out.

  • Briquettes
  • Wood
  • Oil gas
  • Pitch creosote mixture
Q.32

Fusion point of coal ash increases with increase in its __________ content.

  • iron sulphate
  • iron silicate
  • lime and magnesia
  • all (a), (b) and (c)
Q.33

Pick out the wrong statement.

  • Pulverised fuel can be completely burnt with less percentage of excess air compared to lump coal.
  • Low grade coal can be used, but generally high volatile matter coals are more suitable for making pulverised fuel.
  • Regulation of furnace temperature and atmosphere (oxidising or reducing) is easily possible with pulverised fuel firing.
  • none of these.
Q.34

Narrow coke ovens as compared to wider coke ovens

  • produce smaller coke.
  • produce stronger coke.
  • require less time of carbonisation.
  • all (a), (b) and (c).
Q.35

The difference between total carbon and fixed carbon of coal will be minimum in case of

  • lignite
  • bituminous coal
  • anthracite
  • high temperature coke (V.M < 0.5%)
Q.36

Main constituents of benzol are

  • benzene, toluene & xylene.
  • tar & creosote.
  • ammonia & phenol.
  • anthracene & phenol.
Q.37

Height of coke oven is limited (say maximum upto 7 metres) mainly by the

  • problem of uniform heating along its height.
  • structural strength of silica bricks.
  • problem in door cleaning.
  • buckling of ram of pusher car at the time of coke pushing.
Q.38

Out of the following fuels, the difference between the net and gross calorific value is maximum in case of

  • pitch
  • fuel oil
  • blast furnace gas
  • bituminous coal
Q.39

__________ prohibits the use of alcohols directly in petrol engines.

  • Low octane number
  • High cost & availability
  • Low flash point
  • Low calorific value
Q.40

Caking index of the coal blend used for the manufacture of metallurgical coke should be around

  • 5
  • 21
  • 40
  • 48
Q.41

Which of the following petrographic constituents of coal is non-coking ?

  • Vitrain
  • Clarain
  • Durain
  • Fussain
Q.42

Dry air required to burn 1 kg of carbon completely may be around __________ kg.

  • 11
  • 2
  • 20
  • 38
Q.43

The hottest part of the flame lies in its____zone.

  • non-luminous
  • luminous
  • yellow
  • unburnt gases
Q.44

Higher fuel combustion efficiency can not be achieved by

  • preheating of fuel gases & combustion air.
  • reducing sulphur content in the fuel.
  • adopting proper fuel firing technique & fuel preparation.
  • supplying correct amount of combustion air.
Q.45

With increase in moisture content of coal, its

  • calorific value increases sometimes.
  • bulk density always decreases.
  • clinkering tendency during combustion increases.
  • none of these.
Q.46

__________ has the widest inflammability limit (explosion limit) of all the gases.

  • Hydrogen
  • Carbon monoxide
  • Acetylene
  • Methane
Q.47

Percentage of methane in coke oven gas may be around

  • 5
  • 15
  • 25
  • 50
Q.48

Main component of sewage gas produced during aneorobic decomposition of organic waste (by suitable bacteria) during sewage disposal is

  • H2
  • CH4
  • CO2
  • N2
Q.49

Proximate analysis of coal determines its __________ content.

  • moisture, ash, sulphur & volatile matter.
  • moisture, volatile matter, ash & fixed carbon.
  • moisture, sulphur, nitrogen & fixed carbon.
  • none of these.
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