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 : 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 : 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
Last Answer : (C) Friability & oxygen content
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)
Last Answer : (C) Both (A) & (B)
Description : Pick out the correct statement. (A) Oxygen content decreases from lignite to bituminous coal as the coalification increases (B) The less the oxygen content, better is the coal, as it reduces the calorific value (C ... capacity of coal increases and the caking power decreases (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : A coal having higher volatile matter content will necessarily have lower (A) Ash fusion temperature (B) Calorific value (C) Ignition temperature (D) Caking index
Last Answer : (C) Ignition temperature
Description : With increase in moisture content of coal, its (A) Calorific value increases (B) Caking properties diminish (C) Swelling during carbonisation becomes excessive (D) None of these
Last Answer : (B) Caking properties diminish
Description : The weathering index of a coal (A) Gives an idea of the fusion temperature of ash (B) Is related to its calorific value (C) Is a measure of its size stability, when stored & exposed to weather (D) Is a measure of its caking tendency
Last Answer : (C) Is a measure of its size stability, when stored & exposed to weather
Description : Weathering of coal during storage causes (A) Reduction in coal size (B) Increase in its friability (C) Decrease in its caking capacity (D) All (A), (B) and (C)
Description : __________ of the coal is the basis for Seylor's coal classification. (A) Proximate analysis (B) Ultimate analysis (C) Caking index (D) Calorific value
Last Answer : (B) Ultimate analysis
Description : Coke oven gas produced by high temperature carbonisation of coal (as compared to that produced by low temperature carbonisation), has (A) Higher calorific value (B) Lower hydrogen content (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (D) Neither (A) nor (B)
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 : In high temperature carbonisation of coal compared to low temperature carbonisation (A) Yield of ammonia is less (B) Aromatic content of tar is low (C) H2 content in the coke oven gas is more (D) Calorific value of the coke oven gas is lower
Last Answer : (C) H2 content in the coke oven gas is more
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 : Fat' coal means a coal having (A) Low calorific value (B) High volatile matter (C) Low ash content
Last Answer : (B) High volatile matter
Description : A coal with high ash content (A) Has higher calorific value (B) Is harder and stronger (C) Is not subjected to washing (D) Has low quantity of mineral matter
Last Answer : (B) Is harder and stronger
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)
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
Description : Washing of coal decreases its (A) Caking index (B) Mineral matter content (C) Ash content (D) Both (B) and (C)
Last Answer : (B) Mineral matter content
Description : During its calorific value determination by bomb calorimeter, coal is combusted by (A) Air (B) Oxygen (C) Oxygen enriched air (D) None of these
Last Answer : (C) Oxygen enriched air
Description : Which of the following statement (s) regarding India's coal reserves is/are true ? 1. Over 90 percent of total reserves are located in the valleys of Son, Damodar, Mahanadi and Godavari 2. Indian coal reserves are characterised ... reserves (a) I only (b) I and III (c) II and III (d) I, II and III
Last Answer : Ans: (c)
Description : In high temperature carbonisation (as compared to low temperature carbonisation) of coal (A) Coke oven gas yield is more (B) Tar yield is less but free carbon in tar is more (C) Calorific value of coke oven gas is less (D) All (A), (B) and (C)
Description : Low temperature carbonisation of coal produces (A) Metallurgical coke (B) Soft coke (C) Very low calorific value coke oven gas (D) No by-products
Last Answer : (B) Soft coke
Description : Calorific value of coke even gas produced by low temperature carbonisation of coal is about __________ Kcal/Nm3 . (A) 4000 (B) 2500 (C) 6500 (D) 10000
Last Answer : (C) 6500
Description : As the equilibrium moisture content of the coal increases, its (A) Calorific value increases (B) Swelling number decreases (C) Swelling number increases (D) Bulk density decreases
Last Answer : (B) Swelling number decreases
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 : Rate of low temperature oxidation of coal due to bad storage conditions (A) Decreases with increase in surface area (B) Does not vary with increase in surface area (C) Is more for low volatile ... to high volatile coal (D) Is accelerated by storage in large heaps with small surface to volume ratio
Last Answer : (D) Is accelerated by storage in large heaps with small surface to volume ratio
Description : Low temperature oxidation of coal is accelerated by the (A) Storage in large heaps (B) Storage in compressed piles (C) Absence of porous or friable particles (D) All (A), (B) and (C)
Last Answer : (A) Storage in large heaps
Description : Spontaneous combustion of coal on storage results due to (A) Inadequate ventilation (B) Low temperature oxidation (C) Storage in large heaps with small surface to volume ratio (D) All (A), (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 : A coal gasifier operating at 20 atm. (e.g. Lurgi gasifier) as compared to one operating at atmospheric pressure (e.g. Kopper-Totzek or Winkler gasifier) will produce a gas having (A) Higher ... calorific value (B) Higher carbon monoxide content (C) Lower carbon dioxide content (D) None of these
Last Answer : (A) Higher methane content and thus higher calorific value
Description : . A coal having high volatile matter content will (A) Give less yield of tar and gas on carbonisation (B) Burn with a small non-smoky flame (C) Have a very high calorific value (D) None of these
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)
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 : 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 : 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 : Softening temperature of coal ash is a measure of the __________ of coal. (A) Caking tendency (B) Coking tendency (C) Clinkering tendency (D) Size stability
Last Answer : (C) Clinkering tendency
Description : 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
Last Answer : (C) Heat of combustion
Description : Coals used for the generation of producer gas should have (A) High caking index (B) Low fusion point of ash (C) High volatile matter content (D) Very low ash content (8-10%)
Last Answer : (C) High volatile matter content
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 : For long flame and easy ignition, the coal used should have (A) High volatile matter (B) Low ash (C) High calorific value (D) High ash
Last Answer : (A) High volatile matter
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 : A coal having higher volatile matter content, has lower (A) Smoking tendency on burning (B) Coke oven gas yield on carbonisation (C) Chance of catching fire during storage in open space (D) Ignition temperature
Last Answer : (D) Ignition temperature
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 : Caking index of a coal is a measure of its (A) Abradability (B) Reactivity (C) Agglutinating (binding) properties (D) Porosity
Last Answer : (C) Agglutinating (binding) properties
Description : Which of the following is a measure of the agglutinating (i.e., binding) property of coal? (A) Thickness of plastic layer (B) Caking index (C) Swelling index (D) Gray-king index
Last Answer : (B) Caking index
Description : Pick out the wrong statement. (A) Indian coals on an average contain 25-30% ash as against 10-12% ash in imported coking coal (B) Ammonia is recovered in the form of ammonium sulphate in direct ... indicates poor caking properties of coal (D) Wash oil is used for scrubbing Benzol from coke oven gas
Last Answer : (C) A high swelling index number of coking coal indicates poor caking properties of coal
Description : Caking coal is desirable for (A) Burning on travelling grate (B) Coke making (C) Burning on firebars (D) All (A), (B) and (C)
Last Answer : (B) Coke making
Description : A coal that softens and fuses on heating is (A) Classified (B) Carbonised (C) Caking (D) Non-caking
Last Answer : (C) Caking
Description : A travelling grate stoker is meant for the efficient burning of __________ coal. (A) Caking (B) Pulverised (C) Non-caking (D) High ash
Last Answer : (C) Non-caking