Description : Which is the highest grade of coal whose surface is shining and has the highest calorific value? -Do You Know?
Last Answer : answer:
Description : Which is the highest grade of coal whose surface is shining and has the highest calorific value?
Last Answer : Anthracite
Description : Among the fuels given below, the one with highest calorific value is – (1) Coke (2) Coal (3) Wood (4) Natural gas
Last Answer : (4) Natural gas Explanation: The calorific values of different fuels (in Kcal/kg) in dry state are: Wood: 3500; Coal: 4000-7000; Coke: 6500; and Natural Gas: 8600 Kcal/kg.
Description : Which one of the following gases has the highest calorific value? (1) Natural gas (2) Water gas (3) Coal gas (4) Indane gas
Last Answer : (4) Indane gas Explanation: The basic calorific value for solid and liquid fuels is the gross calorific value at constant volume and for gaseous fuels it is the gross calorific value at constant pressure. The ... Water gas: 4600-4800; and LPG (liquefied petroleum gas such as Indane): 11,900 Kcal/Kg.
Description : 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
Last Answer : (C) Liquefied petroleum gas (LPG)
Description : Which of the following fuels has the highest calorific value per unit mass (kcal/kg)? (A) Coal (B) Kerosene (C) Natural gas (D) Furnace oil
Last Answer : (D) Furnace oil
Description : Which of the following has the highest calorific value? (A) Lignite (B) Sub-bituminous coal (C) Anthracite (D) Peat
Last Answer : (C) Anthracite
Description : Among the fuels given below, the one with highest calorific value is (1) Coke (2) Coal (3) Wood (4) Natural gas
Last Answer : Natural gas
Description : Which one of the following gases has the highest calorific value? (1) Natural gas (2)Water gas (3) Coal gas (4)Indane gas
Last Answer : Indane gas
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 : Use of pulverised coal in boilers provides (A) Higher calorific value (B) Better combustion (C) Smokeless burning (D) Less erosion on furnace wall
Last Answer : (B) Better combustion
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 : 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 : Calorific value of pitch creosote mixture (PCM) i.e., C.T.F.-200 is about (A) 8800 kcal/m3 (B) 8800 kcal/kg (C) Same as that of coal middling (D) 25000 kcal/kg
Last Answer : (B) 8800 kcal/kg
Description : Calorific value of bituminous coal may be around __________ Kcal/kg. (A) 500 (B) 1500 (C) 6500 (D) 20000
Last Answer : (C) 6500
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 : 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 : 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 : 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 : 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)
Last Answer : (D) All (A), (B) and (C)
Description : Use of pulverised coal in boiler furnace provides (A) High calorific value (B) Better combustion (C) Smokeless burning (D) Less erosion on furnace walls
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 : 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 : 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 : 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 : 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 : 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 : 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 : 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 : 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
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 : Pick out the wrong statement. (A) Percentage of ash in coke produced from medium coking coal is more than that in coal (B) The calorific value (kcal/Nm3 ) of coke oven gas reduces on ... plants in India at Talcher (Orissa) and Ramagundam (A.P) employ Kopper-Totzek process of coal gasification
Last Answer : (C) Ash is normally removed as 'fly-ash' in Kopper-Totzek process of coal gasification
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 : 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 : Low temperature oxidation of coal during storage does not decrease its (A) Oxygen content (B) Caking power (C) Calorific value (D) None of these
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 : 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 : 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 : 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 : 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 : 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 : Calorific value of coal middling generated in coal washeries during washing of coal may be around __________ Kcal/kg. (A) 1000 (B) 4000 (C) 6000 (D) 8000
Last Answer : (B) 4000
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)
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 : Out of the following fuels, the difference between the net and gross calorific value is maximum in case of (A) Pitch (B) Fuel oil (C) Blast furnace gas (D) Bituminous coal
Last Answer : (B) Fuel oil
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