Fuels And Combustion MCQs

Option A: 0.5

Option B: 10

Option C: 50

Option D: 500

Correct Answer: 10 ✔

Option A: Gaseous

Option B: Solid

Option C: Liquid

Option D: Both B. and C.

Correct Answer: D. Both B. and C. ✔

Option A: Electricity

Option B: Coke oven gas

Option C: Mixed gas

Option D: Both B. & C.

Correct Answer: D. Both B. & C. ✔

Option A: Produced by low temperature carbonisation of coal

Option B: A domestic fuel

Option C: Used in blast furnaces

Option D: None of these

Correct Answer: Used in blast furnaces ✔

Option A: 10

Option B: 25

Option C: 45

Option D: 60

Correct Answer: 60 ✔

Option A: It is abrasive to the coal pulveriser (i.e. ball mill) and the combustion chamber

Option B: The ash in molten condition gets absorbed in the pores of the refractory lining of the furnace

Option C: The ash retains the sulphur & phosphorus and thus affects the quality of products in

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

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

Option A: Coke oven gas

Option B: Producer gas

Option C: Blast furnace gas

Option D: L.D. converter gas

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

Option A: Higher than

Option B: Lower than

Option C: Same as

Option D: Either A. or B.; depends on the type of coal

Correct Answer: Higher than ✔

Option A: Low reactivity of carbonised residue containing high proportions of iron & sulphur

Option B: Low forced draught and fuel bed temperature

Option C: Thick fire bed and preheated primary air

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

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

Option A: Reduces its consumption in the furnace

Option B: Increases its consumption in the furnace

Option C: Does not affect its consumption in the furnace

Option D: Decreases its hardness and abrasion resistance

Correct Answer: Increases its consumption in the furnace ✔

Option A: Lignite

Option B: Bituminous coal

Option C: Anthracite

Option D: High temperature coke (V.M < 0.5%)

Correct Answer: High temperature coke (V.M < 0.5%) ✔

Option A: Coke oven gas yield is more

Option B: Tar yield is less but free carbon in tar is more

Option C: Calorific value of coke oven gas is less

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

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

Option A: Higher than

Option B: Lower than

Option C: Same as

Option D: None of these

Correct Answer: Higher than ✔

Option A: More

Option B: Less

Option C: Equal

Option D: More or less; (depends on the state of fuel.)

Correct Answer: Less ✔

Option A: A high rank coal

Option B: A coking coal

Option C: Can be used for gasification and steam generation

Option D: A black banded coal which burns with a non-smoky yellowish flame

Correct Answer: Can be used for gasification and steam generation ✔

Option A: Lurgi

Option B: Kopper-Totzek

Option C: Winkler

Option D: None of these

Correct Answer: Lurgi ✔

Option A: High calorific value

Option B: Better combustion

Option C: Smokeless burning

Option D: Less erosion on furnace walls

Correct Answer: Better combustion ✔

Option A: Blast furnace gas

Option B: Coke oven gas

Option C: Natural gas

Option D: Water gas

Correct Answer: Blast furnace gas ✔

Option A: Pitch

Option B: Blast furnace gas

Option C: Petrol

Option D: Refinery gas

Correct Answer: Petrol ✔

Option A: Is non-coking

Option B: Has a high volatile matter content and burns with a luminous smoky flame

Option C: Is a non-banded coal which can be ignited easily with a match stick or candle flame, hence is

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

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

Option A: Coking coals cannot be used

Option B: Low carbon conversion efficiency is achieved

Option C: Entrainment of solids is higher

Option D: Larger quantity of coal can be processed

Correct Answer: Larger quantity of coal can be processed ✔

Option A: H2

Option B: CO

Option C: CH4

Option D: C2H6

Correct Answer: H2 ✔

Option A: Blast furnace gas

Option B: Hydrogen

Option C: Acetylene

Option D: Coke oven gas

Correct Answer: Acetylene ✔

Option A: Carburetted water gas

Option B: Blast furnace gas

Option C: Natural gas

Option D: Producers’ gas

Correct Answer: Natural gas ✔

Option A: Ash disposal problem

Option B: Excessive fly-ash discharge from the stack

Option C: High power consumption in its transportation

Option D: Erosion of induced draft fan blades

Correct Answer: Ash disposal problem ✔

Option A: Furnace oil

Option B: Natural gas

Option C: Coal

Option D: Naphtha

Correct Answer: Natural gas ✔

Option A: y

Option B: 0.95 y

Option C: 1.05 y

Option D: 1.8 y

Correct Answer: y ✔

Option A: Exothermic

Option B: Endothermic

Option C: Catalytic

Option D: Autocatalytic

Correct Answer: Endothermic ✔

Option A: 30

Option B: 300

Option C: 3,000

Option D: 30,000

Correct Answer: 30 ✔

Option A: High volatile matter

Option B: Low ash

Option C: High calorific value

Option D: High ash

Correct Answer: High volatile matter ✔

Option A: Absorption in wash oil

Option B: Adsorption on bog iron bed

Option C: Bubbling it through dilute sulphuric acid

Option D: Adsorption on silica gel

Correct Answer: Adsorption on bog iron bed ✔

Option A: Amount of heat liberated

Option B: Flame temperature

Option C: Flue gas temperature

Option D: Any of the above

Correct Answer: Amount of heat liberated ✔

Option A: H2 & CO

Option B: H2 & CH4

Option C: CH4 & CO

Option D: H2 & CO2

Correct Answer: H2 & CH4 ✔

Option A: Temperature of the flue gas

Option B: Its height

Option C: Both A. & B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. & B. ✔

Option A: Higher calorific value

Option B: Lower hydrogen content

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: D. Neither A. nor B. ✔

Option A: Volatiles

Option B: Ash

Option C: Iron

Option D: Moisture

Correct Answer: Volatiles ✔

Option A: LPG

Option B: Coal briquettes

Option C: Tar

Option D: Colloidal fuels

Correct Answer: Tar ✔

Option A: Blast furnace gas

Option B: Coke oven gas

Option C: Carburetted water gas

Option D: Oil refinery gas

Correct Answer: Oil refinery gas ✔

Option A: Calorific value increases sometimes

Option B: Bulk density always decreases

Option C: Clinkering tendency during combustion increases

Option D: None of these

Correct Answer: None of these ✔

Option A: 8800

Option B: 12000

Option C: 14000

Option D: 16000

Correct Answer: 8800 ✔

Option A: Gives flue gas analysis on dry basis

Option B: Determines N2 in flue gas indirectly

Option C: Can’t determine CO in flue gas, if it is < 0.2%

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

Correct Answer: D. All A., B. & C. ✔

Option A: Strength

Option B: Bulk density

Option C: Reactivity

Option D: None of these

Correct Answer: Strength ✔

Option A: Preheating, blending and de-ashing the coal

Option B: Stamped charging of coal

Option C: Dry quenching of coke

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

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

Option A: Nitrogen

Option B: Air

Option C: Phenolic water

Option D: Carbon dioxide

Correct Answer: Nitrogen ✔

Option A: Moisture, ash, sulphur & volatile matter

Option B: Moisture, volatile matter, ash & fixed carbon

Option C: Moisture, sulphur, nitrogen & fixed carbon

Option D: None of these

Correct Answer: Moisture, volatile matter, ash & fixed carbon ✔

Option A: 21

Option B: 77

Option C: 79

Option D: 29

Correct Answer: 21 ✔

Option A: 10

Option B: 25

Option C: 65

Option D: 90

Correct Answer: 65 ✔

Option A: 50

Option B: 70

Option C: 85

Option D: 100

Correct Answer: 100 ✔

Option A: 3 & 10

Option B: 10 & 3

Option C: 10 & 20

Option D: 15 & 8

Correct Answer: 10 & 3 ✔

Option A: Low calorific value

Option B: High volatile matter

Option C: Low ash content

Option D: Non smoking tendency

Correct Answer: High volatile matter ✔

Option A: Scrubbing with wash oil (a petroleum product)

Option B: Adsorbing on bog iron bed

Option C: Absorbing in vetro-coke solution

Option D: None of these

Correct Answer: Scrubbing with wash oil (a petroleum product) ✔

Option A: 0

Option B: 100

Option C: In between 0 and 100

Option D: More than 100

Correct Answer: 0 ✔

Option A: Lignite

Option B: Sub-bituminous coal

Option C: Anthracite

Option D: Peat

Correct Answer: Anthracite ✔

Option A: CO

Option B: CO2

Option C: H2O

Option D: Both B. & C.

Correct Answer: D. Both B. & C. ✔

Option A: 3-5

Option B: 25-30

Option C: 60-65

Option D: 95-100

Correct Answer: 25-30 ✔

Option A: H2

Option B: CO

Option C: CH4

Option D: C2H6

Correct Answer: C2H6 ✔

Option A: 1800

Option B: 800

Option C: 4500

Option D: 10000

Correct Answer: 1800 ✔

Option A: 20

Option B: 35

Option C: 55

Option D: 80

Correct Answer: 80 ✔

Option A: Calorific value

Option B: Octane number

Option C: Specific gravity

Option D: Viscosity

Correct Answer: Calorific value ✔

Option A: Vitrain

Option B: Clarain

Option C: Durain

Option D: Fussain

Correct Answer: Fussain ✔

Option A: Neumann reversal

Option B: Shift conversion

Option C: Boudouard

Option D: Reduction

Correct Answer: Boudouard ✔

Option A: Is not undesirable

Option B: Reduces its calorific value

Option C: Badly affects the quality of steel

Option D: Increases its caking power

Correct Answer: Badly affects the quality of steel ✔

Option A: Blast furnace gas

Option B: Coke oven gas

Option C: Water gas

Option D: Carburetted water gas

Correct Answer: Blast furnace gas ✔

Option A: 1300

Option B: 500

Option C: 4500

Option D: 9000

Correct Answer: 1300 ✔

Option A: High amount/current of combustion air

Option B: Low amount/current of combustion air

Option C: Preheated secondary air

Option D: Very little excess air

Correct Answer: High amount/current of combustion air ✔

Option A: Use of thick fire bed

Option B: Low fusion point of ash (< 1100° C)

Option C: Use of preheated primary air

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

Correct Answer: D. All A., B. & C. ✔

Option A: 4000

Option B: 2500

Option C: 6500

Option D: 10000

Correct Answer: 6500 ✔

Option A: Caking tendency

Option B: Coking tendency

Option C: Clinkering tendency

Option D: Size stability

Correct Answer: Clinkering tendency ✔

Option A: CO2 : 6.26, CO : 1.56, O2 : 3.91, H2O :15.66, N2 : 72.60

Option B: CO2 : 7.42, CO : 1.86, O2 : 4.64, N2:86.02

Option C: CO2 : 6.39, CO : 1.60, O2 : 3.99, H2O:25.96, N2:72.06

Option D: CO2 : 7.60, CO : 1.90, O2 : 4.75, N2 : 85.74

Correct Answer: CO2 : 7.42, CO : 1.86, O2 : 4.64, N2:86.02 ✔

Option A: Preheating of fuel gases & combustion air

Option B: Reducing sulphur content in the fuel

Option C: Adopting proper fuel firing technique & fuel preparation

Option D: Supplying correct amount of combustion air

Correct Answer: Reducing sulphur content in the fuel ✔

Option A: 50

Option B: 1000

Option C: 5000

Option D: 10000

Correct Answer: 50 ✔

Option A: H2

Option B: CH4

Option C: CO

Option D: None of these

Correct Answer: CH4 ✔

Option A: 21% excess air has been used for combustion

Option B: 21% excess oxygen has been used for combustion

Option C: Complete combustion of fuel has taken place

Option D: No excess air has been used for combustion

Correct Answer: Complete combustion of fuel has taken place ✔

Option A: 5

Option B: 15

Option C: 25

Option D: 50

Correct Answer: 5 ✔

Option A: Hydrolysis

Option B: Fermentation

Option C: Oxidation

Option D: Dehydration

Correct Answer: Fermentation ✔

Option A: 0.5

Option B: 1.5

Option C: 2.5

Option D: 3.5

Correct Answer: 0.5 ✔

Option A: Theoretically required amount of air

Option B: More than theoretically required amount of air

Option C: Less than theoretically required amount of air

Option D: Theoretically required amount of oxygen

Correct Answer: Theoretically required amount of oxygen ✔

Option A: 1

Option B: 7

Option C: 22

Option D: 46

Correct Answer: 22 ✔

Option A: Hydrogen content of coke oven gas increases due to cracking of hydrocarbons

Option B: Methane content in the coke oven gas decreases and carbon monoxide content increases

Option C: Calorific value of the coke oven gas decreases due to cracking of hydrocarbons which is not

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

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

Option A: Nickel

Option B: Vanadium

Option C: Silica gel

Option D: Alumina

Correct Answer: Nickel ✔

Option A: 1000

Option B: 4000

Option C: 8000

Option D: 15000

Correct Answer: 8000 ✔

Option A: Oxygen content

Option B: Caking power

Option C: Calorific value

Option D: None of these

Correct Answer: None of these ✔

Option A: Air

Option B: Oxygen

Option C: Either A. or B.

Option D: Either A. or B. without gain or loss of heat

Correct Answer: D. Either A. or B. without gain or loss of heat ✔

Option A: Petrol

Option B: Diesel

Option C: Kerosene

Option D: LPG

Correct Answer: Kerosene ✔

Option A: Higher calorific value

Option B: Lower sulphur content

Option C: Higher emissivity (0.8-0.9) resulting in higher radiation heat transfer rate

Option D: Both A. and B.

Correct Answer: D. Both A. and B. ✔

Option A: Ammonia yield is more

Option B: Aliphatic tar is produced

Option C: Free carbon in tar is more

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

Correct Answer: Aliphatic tar is produced ✔

Option A: Multicyclones

Option B: Bag filter

Option C: Wet scrubber

Option D: Hydrocyclones

Correct Answer: Bag filter ✔

Option A: Speed of the fan

Option B: Damper

Option C: Variation in the pitch of the fan blades

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

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

Option A: CSR & CRI

Option B: Ash content

Option C: Moisture content

Option D: Volatile matter content

Correct Answer: CSR & CRI ✔

Option A: Lower bulk density

Option B: Lower strength

Option C: Higher reactivity

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

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

Option A: High caking index

Option B: Low fusion point of ash

Option C: High volatile matter content

Option D: Very low ash content (8-10%)

Correct Answer: High volatile matter content ✔

Option A: Burning on travelling grate

Option B: Coke making

Option C: Burning on firebars

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

Correct Answer: Coke making ✔

Option A: Smoking tendency on burning

Option B: Coke oven gas yield on carbonisation

Option C: Chance of catching fire during storage in open space

Option D: Ignition temperature

Correct Answer: Ignition temperature ✔

Option A: Coke

Option B: Anthracite

Option C: Coal having low fusion point of its ash

Option D: Coal having high fusion point of its ash

Correct Answer: Coal having low fusion point of its ash ✔

Option A: Scale losses of the furnace stock

Option B: Calorific value of the fuel

Option C: Flame temperature

Option D: None of these

Correct Answer: Flame temperature ✔

Option A: Coke oven gas

Option B: Blast furnace gas

Option C: Natural gas

Option D: None of these

Correct Answer: Blast furnace gas ✔

Option A: Lower ignition temperature

Option B: Narrower limit of inflammability

Option C: Higher calorific value

Option D: Lower theoretical flame temperature

Correct Answer: Lower theoretical flame temperature ✔

Option A: Carburetted water gas

Option B: Gobar gas

Option C: Natural gas

Option D: LPG

Correct Answer: LPG ✔

Option A: Burn CO to CO2

Option B: Dry and transport the coal

Option C: Have proper combustion by supplying it around the burner

Option D: Preheat the tertiary air used for complete combustion of CO to CO2

Correct Answer: Dry and transport the coal ✔

Option A: Reduction in coal size

Option B: Increase in its friability

Option C: Decrease in its caking capacity

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

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