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
Description : 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
Last Answer : (D) None of these
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
Description : Gasification of the solid fuel converts its organic part into combustible by interaction with air/oxygen and steam so as to obtain a secondary gaseous fuel of high calorific value having no ash. Gasification reactions are ... __________ °C. (A) 400-500 (B) 900-1000 (C) 1400-1500 (D) 1700-1800
Last Answer : (B) 900-1000
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)
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
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
Description : A gaseous fuel in order to develop luminosity on burning, must contain (A) Carbon monoxide (B) Hydrocarbons (C) Hydrogen (D) Oxygen
Last Answer : (B) Hydrocarbons
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
Description : Junker's calorimeter is used to determine the calorific value of (A) Pulverised coal (B) Gaseous fuels (C) Fuel oil (D) None of these
Last Answer : (B) Gaseous fuels
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
Description : 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 ... and net calorific value of a fuel is the same, if it does not contain hydrogen or hydrocarbons
Last Answer : (A) Carburetted water gas is also called blue gas
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)
Description : During combustion of a gaseous fuel, the presence of a non-luminous flame is an indication of the (A) Incomplete combustion (B) Complete combustion (C) High oxygen in flue gas (D) None of these
Last Answer : (B) Complete combustion
Description : 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
Last Answer : (B) 25-30
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)
Description : Bomb calorimeter is used for the determination of calorific value of the __________ fuels. (A) Gaseous (B) Solid (C) Liquid (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
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
Description : 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
Last Answer : (D) Oxygen content
Description : Oxygen percentage in the flue gas coming out of a gaseous fuel fired furnace should be ideally about __________ percent. (A) < 2 (B) < 5 (C) < 8 (D) < 10
Last Answer : (A) < 2
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)
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)
Description : Which of the following gaseous fuels has the lowest calorific value? (A) Gobar gas (B) Refinery gas (C) Converter gas (D) Blast furnace gas
Last Answer : (D) Blast furnace gas
Description : Which of the following gaseous fuels is likely to have the highest gross calorific value? (A) Sewage gas (B) LPG (C) Producer gas (D) Natural gas
Last Answer : (B) LPG
Description : Which of the following gaseous fuels has the highest net calorific value (kcal/Nm3 )? (A) Producer gas (B) Carburetted water gas (C) Natural gas (D) Liquefied petroleum gas
Last Answer : (D) Liquefied petroleum gas
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)
Description : Ratio of primary air to secondary air increases with increase in the rank of coal, because the (A) High rank coals have higher amount of volatile matter (B) Ratio of fixed carbon to volatile matter increases (C) Oxygen content progressively decreases (D) Calorific value of the coal increases
Last Answer : (B) Ratio of fixed carbon to volatile matter increases
Description : Natural gas recovered along with crude oil from oil wells is called wet natural gas which has a higher __________ compared to the dry natural gas. (A) Unsaturated hydrocarbon content (B) Calorific value (C) Quantity of propane (D) Quantity of butane
Last Answer : (B) Calorific value
Description : Calorific value of dry wood may be around __________ Kcal/kg. (A) 5 (B) 50 (C) 500 (D) 5000
Last Answer : (A) 5
Description : Calorific value of a typical dry anthracite coal may be around __________ Kcal/kg. (A) 1000 (B) 4000 (C) 8000 (D) 15000
Last Answer : (C) 8000
Description : With increase in the oxygen content of the coal, its __________ decreases. (A) Calorific value (B) Caking power (C) Both (A) & (B) (D) Neither (A) nor (B)
Description : 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
Last Answer : (C) Brittleness of steel made by using it
Description : Washing of coal (A) Reduces its sulphur and ash content (B) Controls its ash fusibility and increases its calorific value (C) Improves its coking properties (D) All (A), (B) and (C)
Description : The unit of calorific value of fuel is __________ . a) Kj /Kg b) J/Kg c)Kj /g d)J/g
Last Answer : a) Kj /Kg
Description : Ultimate analysis of coal determines its __________ content. (A) Carbon, hydrogen, nitrogen & sulphur (B) Carbon, ash, sulphur & nitrogen (C) Carbon, sulphur, volatile matter & ash (D) Carbon, volatile matter, ash & moisture
Last Answer : (A) Carbon, hydrogen, nitrogen & sulphur
Last Answer : (C) Carbon, sulphur, volatile matter & ash
Description : In low temperature carbonisation of coal as compared to high temperature carbonisation __________ produced is less. (A) Difference in gross & net calorific value of the coke oven gas (B) Free carbon content in tar (C) Yield percentage of coke (D) Yield of ammonia present in coke oven gas
Last Answer : (A) Difference in gross & net calorific value of the coke oven gas
Description : Two elements which can form a large number of compounds are (1) Carbon and Hydrogen (2) Carbon and Nitrogen (3) Carbon and Oxygen (4) Carbon and Sulphur
Last Answer : (1) Carbon and Hydrogen Explanation: The carbon-hydrogen bond (C-H bond) is a bond between carbon and hydrogen atoms that can be found in many organic compounds. Compound classes ... bonds are alkanes, alkenes, alkynes, and aromatic hydrocarbons. Collectively they are known as hydrocarbons.
Description : About 98 percent of the mass of every living organism is composed of just six elements including carbon, hydrogen, nitrogen, oxygen and (a) sulphur and magnesium (b) magnesium and sodium (c) calcium and phosphorus (d) phosphorus and sulphur.
Last Answer : (d) phosphorus and sulphur.
Last Answer : Carbon and Hydrogen
Description : Which one of the following is not a gaseous biogeochemical cycle in ecosystem? (a) Sulphur cycle (b) Phosphorus cycle (c) Nitrogen cycle (d) Carbon cycle
Last Answer : b) Phosphorus cycle
Description : In which of the following both pairs have correct combination? (a) Gaseous nutrient cycle, Sedimentary nutrient cycle Nitrogen and Sulphur, Carbon and Phosphorus (b) Gaseous nutrient cycle ... (d) Gaseous nutrient cycle, Sedimentary nutrient cycle Carbon and Sulphur, Nitrogen and Phosphorus
Last Answer : (c) Gaseous nutrient cycle, Sedimentary nutrient cycle Carbon and Nitrogen, Sulphur and Phosphorus
Description : Which one of the following is not a gaseous biogeochemical cycle in ecosystem ? (1) Carbon cycle (2) Sulphur cycle (3) Phosphorus cycle (4) Nitrogen cycle
Last Answer : (3) Phosphorus cycle
Description : Presence of phosphorous in metallurgical coal (A) Is not undesirable (B) Reduces its calorific value (C) Badly affects the quality of steel
Last Answer : (C) Badly affects the quality of steel
Description : The Classical example of redox reaction is Combustion of fossil fuel. During combustion of fossil fuels, the carbon compound in the fossil fuel reacts with oxygen in the presence of a heat source to ... to react with oxygen, so the energy used in portion of combustion is an endothermic reaction.
Last Answer : Combustion of fossil fuel
Description : Pick out the wrong statement. (A) Minimum number of degree of freedom of a system is zero (B) Degree of freedom of a system containing a gaseous mixture of helium, carbon ... ) Enthalpy and internal energy change is zero during phase change processes like melting, vaporisation and sublimation
Last Answer : (D) Enthalpy and internal energy change is zero during phase change processes like melting, vaporisation and sublimation
Description : Ozone-hole in the atmosphere is largely caused by the presence of (1) Oxygen (2) Hydrogen (3) Chloro-floro-carbon (4) Radio-active waste
Last Answer : Chloro-floro-carbon
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
Last Answer : (1) Carbon dioxide and Methane Explanation: The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone. When ranked by their direct contribution to the greenhouse ... 72 %, Carbon Dioxide: 9- 26 %, Methane: 4-9 % and Ozone: 3-7 %.
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 tetraflouride and Nitrous oxide
Last Answer : Carbon dioxide and Methane
Description : The most important property for a jet fuel is its (A) Viscosity (B) Freezing point (C) Calorific value (D) Flash poin
Last Answer : (B) Freezing point