Which of the following constituents of a fuel does not contribute to its calorific value on combustion? (A) Hydrogen (B) Sulphur (C) Carbon (D) None of these

Which of the following constituents of a fuel does not contribute to its
calorific value on combustion?
(A) Hydrogen
(B) Sulphur
(C) Carbon
(D) None of these
by

1 Answer

Answer :

(D) None of these
by

Related questions

Presence of __________ in a dry gaseous fuel does not contribute to its calorific value. (A) Sulphur (B) Oxygen (C) Hydrogen (D) Carbon

Description : Presence of __________ in a dry gaseous fuel does not contribute to its calorific value. (A) Sulphur (B) Oxygen (C) Hydrogen (D) Carbon

Last Answer : (B) Oxygen

A liquid/gaseous fuel containing hydrocarbons and high amount of sulphur is burnt with 40% excess air. The flue gas still contains large amount of carbon monoxide. This may be due to the (A) Presence of large quantity of hydrogen in the fuel (B) Low calorific value of the fuel (C) High sulphur content in the fuel (D) Lack of thorough mixing of fuel with air

Description : A liquid/gaseous fuel containing hydrocarbons and high amount of sulphur is burnt with 40% excess air. The flue gas still contains large amount of carbon monoxide. This may be due to the (A) Presence of large ... fuel (C) High sulphur content in the fuel (D) Lack of thorough mixing of fuel with air

Last Answer : (D) Lack of thorough mixing of fuel with air

The optimum percentage of excess air for combustion depends upon the__________ of the fuel.(A) Type (solid, liquid or gaseous)(B) Calorific value(C) Sulphur content(D) Ignition temperature

Description : The optimum percentage of excess air for combustion depends upon the__________ of the fuel. (A) Type (solid, liquid or gaseous) (B) Calorific value (C) Sulphur content (D) Ignition temperature

Last Answer : (A) Type (solid, liquid or gaseous)

Pick out the wrong statement. (A) High concentration of oxygen in flue gas means high stack loss (B) Gaseous fuels require the least % excess air for complete combustion (C) The ratio of fixed carbon to volatile matter percentage in coal is called its 'fuel ratio' (D) Calorific value of natural gas is more than that of LPG

Description : Pick out the wrong statement. (A) High concentration of oxygen in flue gas means high stack loss (B) Gaseous fuels require the least % excess air for complete combustion (C) The ratio of fixed carbon to ... coal is called its 'fuel ratio' (D) Calorific value of natural gas is more than that of LPG

Last Answer : (D) Calorific value of natural gas is more than that of LPG

Gross and net calorific value of a fuel will be the same (A) If its ash content is zero (B) If its carbon content is very low (C) If its hydrogen/hydrogen compound content is zero (D) Under no circumstances

Description : Gross and net calorific value of a fuel will be the same (A) If its ash content is zero (B) If its carbon content is very low (C) If its hydrogen/hydrogen compound content is zero (D) Under no circumstances

Last Answer : (C) If its hydrogen/hydrogen compound content is zero

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 (A) More (B) Less (C) Same (D) Data insufficient; can't be predicted

Description : 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 (A) More (B) Less (C) Same (D) Data insufficient; can't be predicted

Last Answer : (C) Same

Pick out the wrong statement: (A) Carburetted water gas is also called blue gas (B) Coals are divided in four species according to their carbon content in Seylor's classification (C) Carbonisation time in a by-product coke oven is about 16 hours (D) Gross and net calorific value of a fuel is the same, if it does not contain hydrogen or hydrocarbons

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Last Answer : (A) Carburetted water gas is also called blue gas

Explain higher and lower calorific value of a coal having following composition by mass Carbon 81%,Hydrogen 7%, Oxygen 8%,Nitrogen 2.5%, sulphur 1.5% and remaining is ash

Description : Explain higher and lower calorific value of a coal having following composition by mass Carbon 81%,Hydrogen 7%, Oxygen 8%,Nitrogen 2.5%, sulphur 1.5% and remaining is ash

Last Answer : Carbon C = 81% = 0.81 Hydrogen = H2 = 7% = 0.07 Oxygen = O2 = 8% = 0.08 Nitrogen = N = 2.5% = 0.025 Sulphur = S =1.5% = 0.015 Ash = 2.5% = 0.025 Dulong's formula: H.C.V. of coal = 33800 C + 144500 ... = H.C.V.- 9H2 x 2442 KJ / Kg = 36187.5- 9 x 0.07 x 2442 L.C.V. of coal = 34649.04 KJ / Kg 

Which of the following is the most major constituents of air pollutants? (A) Oxides of sulphur (B) Oxides of nitrogen (C) Carbon monoxide (D) Hydrogen sulphide

Description : Which of the following is the most major constituents of air pollutants? (A) Oxides of sulphur (B) Oxides of nitrogen (C) Carbon monoxide (D) Hydrogen sulphide

Last Answer : (A) Oxides of sulphur

Preheating of combustion air is done to (A) Increase the adiabatic flame temperature (B) Increase the calorific value of the fuel (C) Complete the combustion of fuel (D) Reduce its requirement for effecting the complete combustion

Description : Preheating of combustion air is done to (A) Increase the adiabatic flame temperature (B) Increase the calorific value of the fuel (C) Complete the combustion of fuel (D) Reduce its requirement for effecting the complete combustion

Last Answer : (A) Increase the adiabatic flame temperature

Coke oven gas is a better fuel than blast furnace gas, because of its higher (A) Calorific value, cleanliness and relatively low distribution cost (due to its low specific gravity) (B) Adiabatic flame temperature (C) Heat release rate (thus requiring smaller combustion chamber) (D) All (A), (B) and (C)

Description : Coke oven gas is a better fuel than blast furnace gas, because of its higher (A) Calorific value, cleanliness and relatively low distribution cost (due to its low specific gravity) (B) Adiabatic flame temperature ... release rate (thus requiring smaller combustion chamber) (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Temperature of a furnace fired with low calorific value fuel gas (i.e. lean gas) can be increased by (A) Preheating the combustion air (B) Oxygen enrichment of combustion air (C) Preheating the fuel gas (D) All (A), (B) & (C)

Description : Temperature of a furnace fired with low calorific value fuel gas (i.e. lean gas) can be increased by (A) Preheating the combustion air (B) Oxygen enrichment of combustion air (C) Preheating the fuel gas (D) All (A), (B) & (C)

Last Answer : (D) All (A), (B) & (C)

Which of the following advantages is not associated with the use of preheated air for combustion of a fuel in the furnace? (A) Increase in calorific value of the fuel (B) Increase in flame temperature (C) Reduction in scale losses (D) Saving in fuel consumption

Description : Which of the following advantages is not associated with the use of preheated air for combustion of a fuel in the furnace? (A) Increase in calorific value of the fuel (B) Increase in flame temperature (C) Reduction in scale losses (D) Saving in fuel consumption

Last Answer : (A) Increase in calorific value of the fuel

A fuel with high heat release rate will (A) Require smaller combustion chamber (B) Have high calorific value (C) Have high adiabatic flame temperature (D) None of these

Description : A fuel with high heat release rate will (A) Require smaller combustion chamber (B) Have high calorific value (C) Have high adiabatic flame temperature (D) None of these

Last Answer : (A) Require smaller combustion chamber

Use of preheated air for combustion of fuel in the furnace, increases the (A) Scale losses of the furnace stock (B) Calorific value of the fuel (C) Flame temperature (D) None of these

Description : Use of preheated air for combustion of fuel in the furnace, increases the (A) Scale losses of the furnace stock (B) Calorific value of the fuel (C) Flame temperature (D) None of these

Last Answer : (C) Flame temperature

If the specific heat of gaseous products of combustion of a fuel is high, the abiabatic flame temperature will be (A) Low (B) High (C) Very high, if the fuel is of low calorific value (D) None of these

Description : If the specific heat of gaseous products of combustion of a fuel is high, the abiabatic flame temperature will be (A) Low (B) High (C) Very high, if the fuel is of low calorific value (D) None of these

Last Answer : (A) Low(A) Low

Which of the following is not increased by using preheated combustion air in place of ordinary air at room temperature? (A) Calorific value of the fuel (B) Flame temperature achieved (C) Speed of combustion of fuel (D) Heat transfer rate to the stock in the furnace

Description : Which of the following is not increased by using preheated combustion air in place of ordinary air at room temperature? (A) Calorific value of the fuel (B) Flame temperature achieved (C) Speed of combustion of fuel (D) Heat transfer rate to the stock in the furnace

Last Answer : (A) Calorific value of the fuel

Tar is a better fuel than furnace oil, because of its (A) Higher calorific value (B) Lower sulphur content (C) Higher emissivity (0.8-0.9) resulting in higher radiation heat transfer rate (D) Both (A) and (B)

Description : Tar is a better fuel than furnace oil, because of its (A) Higher calorific value (B) Lower sulphur content (C) Higher emissivity (0.8-0.9) resulting in higher radiation heat transfer rate (D) Both (A) and (B)

Last Answer : (D) Both (A) and (B)

Coal tar fuels (CTF) as compared to petroleum based fuel oils have higher (A) Calorific value (B) Higher C/H ratio (C) Sulphur content (D) Difference in gross & net calorific value

Description : Coal tar fuels (CTF) as compared to petroleum based fuel oils have higher (A) Calorific value (B) Higher C/H ratio (C) Sulphur content (D) Difference in gross & net calorific value

Last Answer : (B) Higher C/H ratio

Which of the following is not endothermic in nature? (A) Combustion of sulphur (B) Gasification of carbon (C) Thermal cracking of fuel oil (D) Steam reforming of naphtha

Description : Which of the following is not endothermic in nature? (A) Combustion of sulphur (B) Gasification of carbon (C) Thermal cracking of fuel oil (D) Steam reforming of naphtha

Last Answer : (A) Combustion of sulphur

Low temperature oxidation of stored coal results in the (A) Decrease in its caking power & calorific value (B) Decrease in its carbon & hydrogen content (C) Increase in its oxygen content (D) All (A), (B) and (A)

Description : Low temperature oxidation of stored coal results in the (A) Decrease in its caking power & calorific value (B) Decrease in its carbon & hydrogen content (C) Increase in its oxygen content (D) All (A), (B) and (A)

Last Answer : (D) All (A), (B) and (A)

With increase in the temperature of carbonisation of coal (A) Hydrogen content of coke oven gas increases due to cracking ofhydrocarbons(B) Methane content in the coke oven gas decreases and carbon monoxidecontent increases(C) Calorific value of the coke oven gas decreases due to cracking ofhydrocarbons which is not compensated by increase in CO & H2 content(D) All (A), (B) and (C)

Description : With increase in the temperature of carbonisation of coal (A) Hydrogen content of coke oven gas increases due to cracking ofhydrocarbons (B) Methane content in the coke oven gas decreases and carbon monoxide content increases ( ... compensated by increase in CO & H2 content (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

What are the major constituents of typical fly ash particles generated from the combustion of coal? w) acidic and basic oxides x) trace elements y) unburned carbon z) sulfates and phosphates

Description : What are the major constituents of typical fly ash particles generated from the combustion of coal? w) acidic and basic oxides x) trace elements y) unburned carbon z) sulfates and phosphates

Last Answer : ANSWER: W -- ACIDIC AND BASIC OXIDES 

Improper storage condition results in the weathering of coal and spontaneous combustion, which increases its (A) Caking index (B) Yield of carbonised products (C) Friability & oxygen content (D) Calorific value

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Last Answer : (C) Friability & oxygen content

With increase in moisture content of coal, its (A) Calorific value increases sometimes (B) Bulk density always decreases (C) Clinkering tendency during combustion increases (D) None of these

Description : With increase in moisture content of coal, its (A) Calorific value increases sometimes (B) Bulk density always decreases (C) Clinkering tendency during combustion increases (D) None of these

Last Answer : (D) None of these

Coal is pulverised before burning in large capacity boiler furnaces mainly to (A) Ensure its complete combustion (B) Facilitate easy ash removal (C) Enhance its calorific value (D) Provide trouble free operation

Description : Coal is pulverised before burning in large capacity boiler furnaces mainly to (A) Ensure its complete combustion (B) Facilitate easy ash removal (C) Enhance its calorific value (D) Provide trouble free operation

Last Answer : (A) Ensure its complete combustion

Use of pulverised coal in boilers provides (A) Higher calorific value (B) Better combustion (C) Smokeless burning (D) Less erosion on furnace wall

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Last Answer : (B) Better combustion

With increase in calorific value of fuels, their adiabatic flame temperatures (A) Increase (B) Decrease (C) Remain unchanged (D) May increase or decrease; depends on the quantity of products of combustion

Description : With increase in calorific value of fuels, their adiabatic flame temperatures (A) Increase (B) Decrease (C) Remain unchanged (D) May increase or decrease; depends on the quantity of products of combustion

Last Answer : (D) May increase or decrease; depends on the quantity of products of combustion

Use of pulverised coal in boiler furnace provides (A) High calorific value (B) Better combustion (C) Smokeless burning (D) Less erosion on furnace walls

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Last Answer : (B) Better combustion

Net calorific value is the gross calorific value less the __________ heat of water in the product of combustion when cooled to 15°C(A) Sensible (B) Latent (C) Sensible and latent (D) None of these.

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Last Answer : (C) Sensible and latent

Change of heat content when one mole of compound is burnt in oxygen at constant pressure is called the (A) Calorific value (B) Heat of reaction (C) Heat of combustion (D) Heat of formation

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Last Answer : (C) Heat of combustion

Acid dew point temperature (ADT) of a flue gas produced by the combustion of a fuel containing 1% sulphur may be about __________ °C. (A) 80 (B) 130 (C) 180 (D) 250

Description : Acid dew point temperature (ADT) of a flue gas produced by the combustion of a fuel containing 1% sulphur may be about __________ °C. (A) 80 (B) 130 (C) 180 (D) 250

Last Answer : (B) 130

Higher fuel combustion efficiency cannot be achieved by (A) Preheating of fuel gases & combustion air (B) Reducing sulphur content in the fuel (C) Adopting proper fuel firing technique & fuel preparation (D) Supplying correct amount of combustion air

Description : Higher fuel combustion efficiency cannot be achieved by (A) Preheating of fuel gases & combustion air (B) Reducing sulphur content in the fuel (C) Adopting proper fuel firing technique & fuel preparation (D) Supplying correct amount of combustion air

Last Answer : (B) Reducing sulphur content in the fuel

High sulphur content in a fuel __________ of the flue gases. (A) Decreases the dew point (B) Increases the dew point (C) Reduces the combustion efficiency by limiting the permissible temperature reduction (D) Both (B) and (C)

Description : High sulphur content in a fuel __________ of the flue gases. (A) Decreases the dew point (B) Increases the dew point (C) Reduces the combustion efficiency by limiting the permissible temperature reduction (D) Both (B) and (C)

Last Answer : (D) Both (B) and (C)

High amount of sulphur and phosphorous in coke causes (A) Decrease in its calorific value (B) Increase in its strength(C) Brittleness of steel made by using it(D) None of these

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Last Answer : (D) All (A), (B) and (C)

Bomb calorimeter can be used to determine the __________ of the coal. (A) Sulphur content (B) Calorific value (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Bomb calorimeter can be used to determine the __________ of the coal. (A) Sulphur content (B) Calorific value (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

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Volumetric composition of flue gas analysed with the Orsat apparatus is : CO2 = 12%, O2 = 8%, CO = nil, N2 = 80%. This flue gas composition indicates that (A) Pure oxygen has been used for combustion (B) Nitrogen percentage in the fuel is very high (C) Excess air has been used for combustion (D) Hydrogen is not present in the fuel

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Last Answer : (C) Excess air has been used for combustion

The main constituents of biogas are (a) methane and hydrogen (b) carbon monoxide and carbon dioxide (c) butane, propane and nitrogen (d) carbon dioxide and methane

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Last Answer : Ans:(d)

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Description : Which one of the following group of gases contribute to the "Green House Effect"? (1) Carbon dioxide and Methane (2) Ammonia and Ozone (3) Carbon monoxide and Sulphur dioxide (4) Carbon tetrailouride and Nitrous oxide

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Which one of the following group of gases contribute to the “Green House Effect”? (1) Carbon dioxide and Methane (2) Ammonia and Ozone (3) Carbon monoxide and Sulphur dioxide (4) Carbon tetraflouride and Nitrous oxide

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Last Answer : (B) 900-1000

Removal of hydrogen from coke oven gas (A) Increases its calorific value (B) Decreases its calorific value (C) Does not alter its calorific value (D) Is not possible on commercial scale

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Low temperature oxidation of coal resulting from bad storage conditions does not decrease its (A) Caking power (B) Calorific value (C) Hydrogen content (D) Oxygen content

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Last Answer : (D) Oxygen content

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Which of the following fuel gases has the highest calorific value? (A) Natural gas (B) Coal bed methane (CBM) (C) Liquefied petroleum gas (LPG) (D) Sewage gas

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Junker's calorimeter is used to determine the calorific value of (A) Pulverised coal (B) Gaseous fuels (C) Fuel oil (D) None of these

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Last Answer : (B) Gaseous fuels

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. (A) 3-5 (B) 25-30 (C) 60-65 (D) 95-100

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Last Answer : (B) 25-30