Q.1

Which will have the least volatile matter and hence will be the most difficult to ignite?

  • Bituminous coal
  • Coke
  • Semi-bituminous coal
  • Aanthracite
Q.2

While the first commercial low temperature coal carbonisation plant is located at Neyveli (in Chennai), the second such plant has been built at

  • Dankuni (West Bengal)
  • Dhanbad
  • Singreni (AP.)
  • Raniganj
Q.3

Ionisation potential applied across the electrodes of electrostatic tar precipitator is around

  • 230 V AC
  • 60 KV AC
  • 230 V DC
  • 60 KV DC
Q.4

The cuprous chloride used in orsat apparatus can absorb

  • only CO
  • both CO and CO2
  • both CO and O2
  • all CO, CO2, and O2.
Q.5

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

  • fixed carbon and having a heat value of 13, 200 BTU/1b.
  • ash and a heating value of 13, 200 BTU/1b.
  • fixed carbon and a heating value of 132 BTU/1b.
  • none of these.
Q.6

Percentage of carbon monoxide in blast furnace gas may be around

  • 8
  • 14
  • 22
  • 52
Q.7

Low temperature carbonisation of coal produces

  • metallurgical coke
  • soft coke
  • very low calorific value coke oven gas
  • no by-products
Q.8

High sulphur (4-6%) coal in India are found in

  • Assam
  • Andhra Pradesh
  • Bengal
  • Madhya Pradesh
Q.9

Sulphur in metallurgical coal

  • contributes to its heating value.
  • affects the quality of steel produced as cracks develop on the surface while rolling the steel.
  • both (a) and (b).
  • neither (a) nor (b).
Q.10

Which of the following is not a binder for coal briquetting ?

  • Coal tar
  • Bitumen
  • Molasses
  • None of these
Q.11

Pick out the wrong statement.

  • Theoretical flame temperature is the temperature attained by the products of combustion, when the fuel is burned without loss or gain of heat.
  • Burning the fuel with theoretically required amount of pure oxygen results in attainment of maximum adiabatic flame temperature.
  • Burning the fuel with excess pure oxygen results in maximum theoretical flame temperature.
  • Adiabatic flame temperatures of actual combustions are always less than the maximum values.
Q.12

Ammonia content in raw coke oven gas is about __________ gm/Nm3.

  • 1
  • 15
  • 50
  • 100
Q.13

Coal is heated in absence of air for 7 minutes at a temperature of about __________ °C, during its volatile matter determination for proximate analysis.

  • 550
  • 750
  • 950
  • 1150
Q.14

Which of the following is not endothermic?

  • Cracking
  • Reforming
  • Gasification
  • Partial oxidation
Q.15

High sulphur content in a fuel __________ of the flue gases.

  • decreases the dew point
  • increases the dew point
  • reduces the combustion efficiency by limiting the permissible temperature reduction
  • , both (b) and (c)
Q.16

Low temperature oxidation and spontaneous combustion of freshly mined coal is accentuated, if

  • it contains large amount of volatile matter.
  • it is stored in tall heaps.
  • smaller fines are stored in large quantity.
  • all (a), (b) and (c).
Q.17

Coking time in narrow by-product coke ovens is around __________ hours.

  • 18
  • 48
  • 8
  • 80
Q.18

High rate of heating of coke ovens

  • may damage its walls due to abrupt excessive swelling of coal.
  • produces larger size coke.
  • increases the time of carbonisation.
  • none of these.
Q.19

A certain thickness of the coal, if stored unscientifically on soft (katcha) ground having no metallic/concrete flooring gets sunked into the ground, which is termed as the 'carpet loss'. The carpet loss may be of the order of __________ cms.

  • 1 to 2
  • 3 to 4
  • 5 to 15
  • 20 to 40
Q.20

Very __________ coals are completely devoid of cokability i.e, it is non coking.

  • young
  • mature
  • both 'a' & 'b'
  • neither 'a' nor 'b'
Q.21

By-products are __________ recovered in 'Beehive ovens'.

  • fully
  • partially
  • not at all
  • negligibly
Q.22

Oxygen content in a flue gas was found to be 4%. It implies that excess air used for combustion was around __________ percent.

  • 4
  • 96
  • 20
  • 40
Q.23

Low temperature oxidation of coal resulting from bad storage conditions does not decrease its

  • caking power
  • calorific value
  • hydrogen content
  • oxygen content
Q.24

Main use of soft coke is as __________ fuel.

  • domestic
  • blastfurnace
  • foundary
  • none of these
Q.25

Pitch creosote mixture (PCM) as compared to furnace oil is a better fuel, because its

  • emissivity factor is higher.
  • sulphur content is lower.
  • flue gas has lower dew point thereby facilitating more waste heat recovery.
  • all (a), (b) and (c).
Q.26

Coal tar fuels (CTF) as compared to petroleum based fuel oils have higher

  • calorific value
  • higher C/H ratio
  • sulphur content
  • difference in gross & net calorific value
Q.27

The sequence of absorption in flue gas analysis by Orsat's apparatus is respectively

  • CO2, O2, CO
  • CO, O2, CO2
  • CO2, CO, O2
  • O2, CO2, CO
Q.28

Mineral matter content (M) and ash content (A) in coal are approximately related as

  • M = 1.1A
  • M = A
  • M = 1.5A
  • M = 2A
Q.29

The main drawback of supplying more excess air in the combustion of fuel is the

  • excessive power requirement of air blower.
  • enhanced sensible heat loss in the flue gas.
  • intermittant and uncontrolled combustion of the fuel.
  • high exit flue gas temperature from the furnace.
Q.30

Width of the coke oven towards coke side is slightly more than that on pusher side to

  • facilitate easy discharging of coke as it swells during carbonisation.
  • facilitate uniform heating of the oven.
  • increase the output of the coke.
  • none of these.
Q.31

Which of the following fuels is generally not used in thermal power plant boiler firing?

  • Furnace oil, light diesel oil and tar/PCM.
  • Pulverised coking coal.
  • Coal middling from washeries.
  • B.F. gas, coke oven gas and L.D. converter gas.
Q.32

Calorific value of pitch creosote mixture (PCM) i.e., C.T.F.-is about

  • 8800 kcal/m3
  • 8800 kcal/kg
  • same as that of coal middling
  • 25000 kcal/kg
Q.33

Volatile matter content of metallurgical coke may be around __________ percent.

  • 1-2
  • 10-15
  • 22-26
  • 30-33
Q.34

In case of pulverised coal fired steam boiler, the secondary air serves the main purpose of

  • transportation of coal.
  • drying of coal.
  • combustion of coal by supplying it around the burner.
  • preheating the primary air.
Q.35

L.D. converter gas (produced in steel plant) comprises mainly of

  • CO (upto 65%) & CO2
  • CO2 & H2
  • CO & O2
  • CO2 & O2
Q.36

Main constituents of purified Lurgi gas are

  • H2, CmHn & CO2
  • CO, H2 & CH4
  • CO2, O2 & CO
  • N2, H2 & CO2
Q.37

The liquid used for the washing of coal in an industrial coal washery is a mixture of water and

  • carbon tetrachloride.
  • sand (40%).
  • mineral oil of high viscosity & specific gravity (1.6)
  • none of these.
Q.38

Spontaneous combustion of coal on storage results due to

  • inadequate ventilation.
  • low temperature oxidation.
  • storage in large heaps with small surface to volume ratio.
  • all (a), (b)and (c).
Q.39

Preheating of a gaseous fuel results in increased

  • flame length
  • flame temperature
  • quantity of flue gas
  • ignition temperature
Q.40

Eschka mixture, which is used for the determination of sulphur in coal, is a mixture of

  • MgO & Na2CO3
  • MgSO4 & BaCl2
  • BaSO4 & NaCl
  • MgCO3 & NaCl
Q.41

Ash content in the middling coal (a byproduct of coal washeries) in India ranges between __________ percent.

  • 15 to 25
  • 35 to 45
  • 55 to 75
  • 75
Q.42

Blast furnace gas is a very poisonous gas because of its predominantly high __________ content.

  • H2O
  • CO2
  • CO
  • CH4
Q.43

Which of the following is a lean fuel gas ?

  • Coke oven gas
  • LPG
  • Blast furnace gas
  • Natural gas
Q.44

Orsat apparatus is meant for

  • gravimetric analysis of flue gas.
  • finding out combustion efficiency.
  • direct determination of nitrogen in flue gas by absorbing it in ammoniacal cuprous chloride.
  • none of these.
Q.45

Coalification means the

  • process of conversion of lignite into anthracite.
  • underground gasification of coal.
  • complete combustion of coal.
  • direct hydrogenation of coal.
Q.46

Hard coke is manufactured from

  • lignite
  • bituminous coal
  • semi-anthracite
  • anthracite
Q.47

Nitrogen in coal

  • is present upto 1-2%.
  • comes from protein in parent vegetable matter.
  • is recovered as ammonia during its carbonisation.
  • all (a), (b) and (c).
Q.48

Advantages of fluidised bed combustion are

  • reduced NOx formation in flue gas.
  • lower furnace operating temperature.
  • high heat transfer rate.
  • all (a), (b) & (c).
Q.49

As time passes, the calorific value of stored coal

  • decreases
  • increases
  • remains unaltered
  • may increase or decrease (depends on the method of storage).
Q.50

Stack (chimney) height in a big thermal power plant is dictated by the

  • pollution control aspect.
  • draught to be created.
  • limitation of constructional facilities.
  • none of these.
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