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 : 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 : 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 : 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 : 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 : Fat coals' are those coals which have very high (A) Caking capacity (B) Volatile matter content (C) Fusion point of its ash (D) Inherent moisture conten
Last Answer : (A) Caking capacity
Description : Mineral matter content (M) and ash content (A) in coal are approximately related as (A) M = 1.1A (B) M = A (C) M = 1.5A (D) M = 2A
Last Answer : (A) M = 1.1A
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 : 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 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 : 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 : 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
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 : Washing of coal does not reduce its (A) S & P content (B) Heating value (C) Fusion point of ash (D) None of these
Last Answer : (D) None of these
Description : Washing of coal (A) Reduces its ash & sulphur content (B) Improves its coking properties (C) Increase the fusion point of its ash by removing chlorine compounds (D) All (A), (B) and (C)
Description : Washing of coal is done to reduce the (A) Inherent impurities (B) Adhering impurities (C) Mineral matter (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : Coal containing large quantity of __________ are difficult to wash. (A) Ash (B) Inherent mineral matter (C) Free impurities (D) Volatile matter
Last Answer : (B) Inherent mineral matter
Description : Mineral matter, 'M' and ash percentage 'A' in coal are roughly related as (A) M = 1.8 A (B) M = 0.5 A (C) M = 1.1 A (D) M = A
Last Answer : (C) M = 1.1 A
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 : Caking index of the coal blend used for the manufacture of metallurgical coke should be around (A) 5 (B) 21 (C) 40 (D) 48
Last Answer : (B) 21
Description : Caking index of coal blend used for blast furnace coke making is about (A) 8 (B) 12 (C) 22 (D) 36
Last Answer : (C) 22
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 : During coking of coal, the ash content (percentage) (A) Increases (B) Decreases (C) Remain constant (D) None of these
Last Answer : (A) Increases
Description : The specific gravity of coal depends mainly on its __________ content. (A) Carbon (B) Volatile matter (C) Ash (D) Moisture
Last Answer : (C) Ash
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
Description : A coal containing high amount of volatile matter will have (A) Low ignition temperature (B) Very little ash content (C) High fusion point of its ash (D) Low adiabatic flame temperature
Last Answer : (A) Low ignition temperature
Description : Proximate analysis of coal determines its __________ content. (A) Moisture, ash, sulphur & volatile matter (B) Moisture, volatile matter, ash & fixed carbon (C) Moisture, sulphur, nitrogen & fixed carbon (D) None of these
Last Answer : (B) Moisture, volatile matter, ash & fixed carbon
Description : Proximate analysis of coal determines its __________ content. (A) Moisture, ash, sulphur & volatile matter (B) Moisture & volatile matter (C) Moisture, sulphur, nitrogen & fixed carbon (D) None of these
Last Answer : (B) Moisture & volatile matter
Last Answer : (C) Carbon, sulphur, volatile matter & ash
Last Answer : Option D
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 : Degree of carbonisation of coal during coke making can be roughly judged by the __________ of the coke produced. (A) Colour (B) Moisture content (C) Ash content (D) Volatile matter
Last Answer : (D) Volatile matter
Description : A coal with high __________ content, would ignite most easily. (A) Fixed carbon (B) Volatile matter (C) Ash (D) Oxygen
Last Answer : (B) Volatile matter
Description : Ignition temperature decreases progressively from anthracite to lignite, because (A) Volatile matter content increases (B) Carbon content decreases (C) Moisture content increases (D) Ash content increases
Last Answer : (A) Volatile matter content increases
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 : 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 : Pick out the wrong statement. (A) Angle of repose of coal increases with its increasing size (B) Specific gravity of coal increases with its increasing maturity (C) Refractive index and reflectance of ... of coal decreases with increases in the volatile matter and decrease in the C/H ratio of coal
Last Answer : (D) Specific heat of coal decreases with increases in the volatile matter and decrease in the C/H ratio of coal
Description : Froth floatation is used for (A) Washing fine coal dust (< 0.5 mm size) (B) Washing lump coal (> 80 mm size) (C) Removing ash from the coal based on difference in specific gravity of coal and ash
Last Answer : (A) Washing fine coal dust (< 0.5 mm size)
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 : The liquid used for the washing of coal in an industrial coal washery is a mixture of water and (A) Carbon tetrachloride (B) Sand (40%) (C) Mineral oil of high viscosity & specific gravity (1.6) (D) None of these
Last Answer : (B) Sand (40%)
Description : Higher percentage of ash in coal meant for the production of metallurgical grade coke (A) Decreases the hardness of coke (B) Decreases the abrasion resistance of coke (C) Causes brittleness in steel (D) None of these
Description : Fixed carbon in coal is defined as (A) That present in volatile matters (B) The total quantity of carbon present in the coal (C) Hundred minus the percentage of volatile matter, ash and moisture (D) The one which is present in the residue after combustion
Last Answer : (C) Hundred minus the percentage of volatile matter, ash and moisture
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 compared to the coal from which it has been made, contains (A) Less volatile matter (B) More carbon (C) Greater percentage of ash (D) All (A), (B) and (C)
Description : Which of the following would require least amount of secondary air for combustion? (A) Coke breeze containing 25% ash and 2% volatile matter (B) Anthracite containing 10% volatile matter and 8% ash ... ash and 25% volatile matter (D) Semi-bituminous coal containing 25% ash and 20% volatile matter
Last Answer : (A) Coke breeze containing 25% ash and 2% volatile matter
Description : Coal is heated in presence of air to a temperature of about __________ °C, while determining its ash content for proximate analysis. (A) 500 (B) 750 (C) 950 (D) 1100
Last Answer : (B) 750
Description : A coal with high ash content is undesirable, as (A) It is abrasive to the coal pulveriser (i.e. ball mill) and the combustion chamber (B) The ash in molten condition gets absorbed in the pores of the ... and stick to the boiler tubes thereby reducing the heat transfer (D) All (A), (B) and (C)