Fuels And Combustion MCQs

Option A: Winkler process

Option B: Kopper-Totzek process

Option C: Lurgi Process

Option D: None of these

Correct Answer: Lurgi Process ✔

Option A: N2 & CH4

Option B: N2 & H2

Option C: N2 & CO

Option D: CH4 & CO2

Correct Answer: N2 & CO ✔

Option A: 20

Option B: 12.5

Option C: 0

Option D: 10

Correct Answer: 0 ✔

Option A: S & P content

Option B: Heating value

Option C: Fusion point of ash

Option D: None of these

Correct Answer: None of these ✔

Option A: Time of carbonisation

Option B: Yield of gas and tar

Option C: Fuel consumption in coking

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Producer gas

Option B: Carburetted water gas

Option C: Natural gas

Option D: Liquefied petroleum gas

Correct Answer: Liquefied petroleum gas ✔

Option A: Facilitate easy discharging of coke as it swells during carbonisation

Option B: Facilitate uniform heating of the oven

Option C: Increase the output of the coke

Option D: None of these

Correct Answer: Facilitate easy discharging of coke as it swells during carbonisation ✔

Option A: Density of the chimney gases

Option B: Height of the chimney

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. and B. ✔

Option A: Porosity

Option B: Coke reactivity index (CRI)

Option C: Critical air blast (CAB) value

Option D: Both B. and C.

Correct Answer: Critical air blast (CAB) value ✔

Option A: Low octane number

Option B: High cost & availability

Option C: Low flash point

Option D: Low calorific value

Correct Answer: High cost & availability ✔

Option A: 0.21

Option B: 3.76

Option C: 4.76

Option D: 0.79

Correct Answer: 3.76 ✔

Option A: Ignites less easily than anthracite

Option B: Is generally coking

Option C: Burns with smoky yellow flame

Option D: Both B. and C.

Correct Answer: D. Both B. and C. ✔

Option A: Reduces its ash & sulphur content

Option B: Improves its coking properties

Option C: Increase the fusion point of its ash by removing chlorine compounds

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Process of conversion of lignite into anthracite

Option B: Underground gasification of coal

Option C: Complete combustion of coal

Option D: Direct hydrogenation of coal

Correct Answer: Process of conversion of lignite into anthracite ✔

Option A: 1

Option B: < 1

Option C: > 1

Option D: Unpredictable

Correct Answer: 1 ✔

Option A: It contains large amount of volatile matter

Option B: It is stored in tall heaps

Option C: Smaller fines are stored in large quantity

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Low

Option B: High

Option C: Very high, if the fuel is of low calorific value

Option D: None of these

Correct Answer: Low ✔

Option A: Combustion of fuel is complete

Option B: Smaller height chimney can be used

Option C: Furnace control is easier

Option D: All A., B. & C.

Correct Answer: D. All A., B. & C. ✔

Option A: 19

Option B: 21

Option C: 23

Option D: 29

Correct Answer: 23 ✔

Option A: 400-500

Option B: 900-1000

Option C: 1400-1500

Option D: 1700-1800

Correct Answer: 900-1000 ✔

Option A: 4

Option B: 96

Option C: 20

Option D: 40

Correct Answer: 20 ✔

Option A: Sewage gas

Option B: Refinery gas

Option C: Producer gas

Option D: Bagasse

Correct Answer: Producer gas ✔

Option A: Contributes to its heating value

Option B: Affects the quality of steel produced as cracks develop on the surface while rolling the steel

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. and B. ✔

Option A: Iron sulphate

Option B: Iron silicate

Option C: Lime and magnesia

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: 900

Option B: 4200

Option C: 7500

Option D: 2000

Correct Answer: 4200 ✔

Option A: 8

Option B: 12

Option C: 22

Option D: 36

Correct Answer: 22 ✔

Option A: Has higher calorific value

Option B: Is harder and stronger

Option C: Is not subjected to washing

Option D: Has low quantity of mineral matter

Correct Answer: Is harder and stronger ✔

Option A: Coal tar

Option B: Bitumen

Option C: Molasses

Option D: None of these

Correct Answer: None of these ✔

Option A: 12 hours

Option B: 2-3 days

Option C: One week

Option D: Two weeks

Correct Answer: 2-3 days ✔

Option A: Calorific value of the fuel

Option B: Flame temperature achieved

Option C: Speed of combustion of fuel

Option D: Heat transfer rate to the stock in the furnace

Correct Answer: Calorific value of the fuel ✔

Option A: Is equal to the heat of formation

Option B: Is always negative

Option C: Can’t be known without calculating it

Option D: Is always positive

Correct Answer: Is always negative ✔

Option A: CO2

Option B: SO2

Option C: Both A. & B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. & B. ✔

Option A: Yield of ammonia is less

Option B: Aromatic content of tar is low

Option C: H2 content in the coke oven gas is more

Option D: Calorific value of the coke oven gas is lower

Correct Answer: H2 content in the coke oven gas is more ✔

Option A: Reduces the coking time

Option B: Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot

Option C: Increases the loss of fine coal dust from the ovens when charging

Option D: None of these

Correct Answer: B. Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot
oven walls ✔

Option A: Type (solid, liquid or gaseous)

Option B: Calorific value

Option C: Sulphur content

Option D: Ignition temperature

Correct Answer: Type (solid, liquid or gaseous) ✔

Option A: Theoretical flame temperature is the temperature attained by the products of combustion, when the fuel is burned without loss or gain of heat

Option B: Burning the fuel with theoretically required amount of pure oxygen results in attainment of maximum adiabatic flame temperature

Option C: Burning the fuel with excess pure oxygen results in maximum theoretical flame temperature

Option D: Adiabatic flame temperatures of actual combustions are always less than the maximum values

Correct Answer: Burning the fuel with excess pure oxygen results in maximum theoretical flame temperature ✔

Option A: Main constituents of LPG are propane and butane

Option B: C.V. of natural gas is about 10000 KCal/Nm3

Option C: C.V. of LPG is about 26000 kcal/Nm3 (11500 kcal/kg)

Option D: L.P.G. is lighter than air

Correct Answer: L.P.G. is lighter than air ✔

Option A: Cokes of high reactivity are obtained from weakly coking coals

Option B: Cokes of high reactivity are obtained from strongly coking coals

Option C: Reactivity of coke is inversely proportional to its absolute density

Option D: Abrasion index of the coke is a measure of its hardness

Correct Answer: Cokes of high reactivity are obtained from strongly coking coals ✔

Option A: Oxygen content decreases from lignite to bituminous coal as the coalification increases

Option B: The less the oxygen content, better is the coal, as it reduces the calorific value

Option C: With increase in oxygen content, moisture holding capacity of coal increases and the caking power decreases

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Pulverised fuel can be completely burnt with less percentage of excess air compared to lump

Option B: Low grade coal can be used, but generally high volatile matter coals are more suitable for

Option C: Regulation of furnace temperature and atmosphere (oxidising or reducing) is easily possible

Option D: None of these

Correct Answer: None of these ✔

Option A: Angle of repose of coal increases with its increasing size

Option B: Specific gravity of coal increases with its increasing maturity

Option C: Refractive index and reflectance of coal increases with the increasing rank of coal

Option D: Specific heat of coal decreases with increases in the volatile matter and decrease in the C/H

Correct Answer: D. Specific heat of coal decreases with increases in the volatile matter and decrease in the C/H
ratio of coal ✔

Option A: Solid fuels

Option B: Gaseous fuels

Option C: Liquid fuels

Option D: Fat coals

Correct Answer: Gaseous fuels ✔

Option A: Inadequate ventilation

Option B: Low temperature oxidation

Option C: Storage in large heaps with small surface to volume ratio

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Tar

Option B: Coke oven gas

Option C: Pitch

Option D: Pulverised coke

Correct Answer: Coke oven gas ✔

Option A: Calorific value increases

Option B: Swelling number decreases

Option C: Swelling number increases

Option D: Bulk density decreases

Correct Answer: Swelling number decreases ✔

Option A: Tar

Option B: Molasses

Option C: Pitch

Option D: Line

Correct Answer: Line ✔

Option A: Natural gas

Option B: Coal bed methane (CBM)

Option C: Liquefied petroleum gas (LPG)

Option D: Sewage gas

Correct Answer: Liquefied petroleum gas (LPG) ✔

Option A: CO

Option B: CO2

Option C: O2

Option D: H2O

Correct Answer: CO ✔

Option A: Blast furnace coke

Option B: Low temperature coke

Option C: Anthracite coal

Option D: Sub-bituminous coal

Correct Answer: Low temperature coke ✔

Option A: < 120

Option B: > 120

Option C: > 280

Option D: 300-600

Correct Answer: < 120 ✔

Option A: Ash

Option B: Volatile matter

Option C: Sulphur (4-6%)

Option D: Moisture

Correct Answer: Sulphur (4-6%) ✔

Option A: High production of CO2

Option B: Low production of CO2

Option C: High production of CO

Option D: Both B. and C.

Correct Answer: D. Both B. and C. ✔

Option A: Air

Option B: Oxygen

Option C: Oxygen enriched air

Option D: None of these

Correct Answer: Oxygen ✔

Option A: Can give ammonia synthesis gas (H2 + N2)

Option B: Is a moving bed reactor

Option C: Cannot use coking coal

Option D: Operate at very high pressure

Correct Answer: Can give ammonia synthesis gas (H2 + N2) ✔

Option A: < 120

Option B: > 120

Option C: < 90

Option D: 90-110

Correct Answer: > 120 ✔

Option A: Coke

Option B: Ammonia

Option C: Tar

Option D: Coke oven gas

Correct Answer: Coke ✔

Option A: Coke breeze

Option B: Soft coke

Option C: Colloidal fuels

Option D: Charcoal

Correct Answer: Coke breeze ✔

Option A: Would require smaller combustion chamber

Option B: Produces very little of tar and gas on carbonisation

Option C: Ignites easily and burns with long smoky flame

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: 10

Option B: 25

Option C: 50

Option D: 75

Correct Answer: 25 ✔

Option A: That present in volatile matters

Option B: The total quantity of carbon present in the coal

Option C: Hundred minus the percentage of volatile matter, ash and moisture

Option D: The one which is present in the residue after combustion

Correct Answer: Hundred minus the percentage of volatile matter, ash and moisture ✔

Option A: Lengthens the flame

Option B: Tends to shorten the flame

Option C: Does not affect the flame length

Option D: Increases the flame temperature

Correct Answer: Lengthens the flame ✔

Option A: 10,000

Option B: 15,000

Option C: 5,000

Option D: 20,000

Correct Answer: 10,000 ✔

Option A: LPG

Option B: Gobar gas

Option C: Coke oven gas

Option D: Carburetted water gas

Correct Answer: LPG ✔

Option A: Benzol

Option B: Pitch-creosote mixture (PCM)

Option C: Naphthalene

Option D: Ethylene

Correct Answer: Ethylene ✔

Option A: 1

Option B: < 1

Option C: > 1

Option D: Unpredictable

Correct Answer: 1 ✔

Option A: Ash

Option B: Sulphur & phosphorus

Option C: Moisture

Option D: None of these

Correct Answer: None of these ✔

Option A: Blast furnace gas

Option B: Coke oven gas

Option C: L.D. converter gas

Option D: None of these

Correct Answer: C. L.D. converter gas ✔

Option A: Increases its calorific value

Option B: Decreases its calorific value

Option C: Does not alter its calorific value

Option D: Is not possible on commercial scale

Correct Answer: Increases its calorific value ✔

Option A: Solid fuels

Option B: Liquid fuels

Option C: Those fuels which are found in the crust of earth

Option D: Premature fuels with low calorific value

Correct Answer: Those fuels which are found in the crust of earth ✔

Option A: Lengthens the flame

Option B: Causes heat loss of fuel by its partial combustion

Option C: Both A. & B.

Option D: Shortens the flame

Correct Answer: C. Both A. & B. ✔

Option A: Pulverised coal

Option B: Gaseous fuels

Option C: Fuel oil

Option D: None of these

Correct Answer: Gaseous fuels ✔

Option A: Lignite

Option B: Bituminous coal

Option C: Anthracite coal

Option D: None of these

Correct Answer: Lignite ✔

Option A: 80-170

Option B: 200-300

Option C: 250-270

Option D: 280-300

Correct Answer: 80-170 ✔

Option A: B.F. gas and coke oven gas

Option B: Coke oven gas and converter gas

Option C: Coke oven gas and L.P.G

Option D: Blast furnace gas and naphtha vapor

Correct Answer: B.F. gas and coke oven gas ✔

Option A: Increase the adiabatic flame temperature

Option B: Increase the calorific value of the fuel

Option C: Complete the combustion of fuel

Option D: Reduce its requirement for effecting the complete combustion

Correct Answer: Increase the adiabatic flame temperature ✔

Option A: 100 to 150

Option B: 350 to 450

Option C: 550 to 650

Option D: 700 to 850

Correct Answer: 350 to 450 ✔

Option A: Ash

Option B: Inherent mineral matter

Option C: Free impurities

Option D: Volatile matter

Correct Answer: Inherent mineral matter ✔

Option A: Produce smaller coke

Option B: Produce stronger coke

Option C: Require less time of carbonisation

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: GCV at constant pressure

Option B: GCV at constant volume

Option C: NCV at constant pressure

Option D: NCV at constant volume

Correct Answer: GCV at constant volume ✔

Option A: Combustion

Option B: Nuclear fission

Option C: Nuclear fusion

Option D: All A., B. & C.

Correct Answer: D. All A., B. & C. ✔

Option A: No possibility of obtaining complete combustion at high temperature

Option B: Always loss of heat from the flame

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. and B. ✔

Option A: Plutonium

Option B: Uranium

Option C: Radium

Option D: Neptunium

Correct Answer: Plutonium ✔

Option A: Decreases

Option B: Increases

Option C: Remain constant

Option D: May increase or decrease, depends on combustibles

Correct Answer: May increase or decrease, depends on combustibles ✔

Option A: 1-2

Option B: 10-15

Option C: 22-26

Option D: 30-33

Correct Answer: 1-2 ✔

Option A: Lignites

Option B: Bituminous coals

Option C: Semi-anthracites

Option D: Anthracites

Correct Answer: Bituminous coals ✔

Option A: High rank coals have higher amount of volatile matter

Option B: Ratio of fixed carbon to volatile matter increases

Option C: Oxygen content progressively decreases

Option D: Calorific value of the coal increases

Correct Answer: Ratio of fixed carbon to volatile matter increases ✔

Option A: 2

Option B: 4

Option C: 6

Option D: 1

Correct Answer: 2 ✔

Option A: 1500

Option B: 3300

Option C: 5400

Option D: 8500

Correct Answer: 3300 ✔

Option A: Much lower

Option B: Much higher

Option C: Same

Option D: Either lower or higher, depends on the type of fuel

Correct Answer: Much lower ✔

Option A: 1

Option B: 5

Option C: 50

Option D: 100

Correct Answer: 5 ✔

Option A: Sulphur

Option B: Oxygen

Option C: Hydrogen

Option D: Carbon

Correct Answer: Oxygen ✔

Option A: 200 meters

Option B: Infinitely long

Option C: More than 105.7 metres

Option D: Equal to the height of the hot gas column producing draught

Correct Answer: Equal to the height of the hot gas column producing draught ✔

Option A: CO

Option B: H2

Option C: CH4

Option D: C2H6

Correct Answer: H2 ✔

Option A: Furnace oil, light diesel oil and tar/PCM

Option B: Pulverised coking coal

Option C: Coal middling from washeries

Option D: B.F. gas, coke oven gas and L.D. converter gas

Correct Answer: Pulverised coking coal ✔

Option A: Heat losses

Option B: Long flame

Option C: Condensation of water vapour from the fuel gas

Option D: None of these

Correct Answer: Heat losses ✔

Option A: Requirement of large volume combustion chamber

Option B: Risk of explosion

Option C: Chances of clinker formation

Option D: Incomplete combustion of coal

Correct Answer: Risk of explosion ✔

Option A: Coke oven gas

Option B: Water gas

Option C: Natural gas

Option D: Producer gas

Correct Answer: Water gas ✔

Option A: Decreases with increase in surface area

Option B: Does not vary with increase in surface area

Option C: Is more for low volatile coal compared to high volatile coal

Option D: Is accelerated by storage in large heaps with small surface to volume ratio

Correct Answer: Is accelerated by storage in large heaps with small surface to volume ratio ✔

Option A: 15-30

Option B: 1-2

Option C: 70-100

Option D: 150-200

Correct Answer: 15-30 ✔

Option A: Carbonisation

Option B: Oxidation

Option C: Coalification

Option D: Gasification

Correct Answer: Gasification ✔