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1) For a cyclone of diameter 0.2 m with a tangential velocity of 15 m/s at the wall, the separation factor is__________________? a. 2250 b. 1125 c. 460 d. 230
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2) Traces of liquid tar fog present in coke oven gas is separated using____________________? a. Electrostatic precipitator b. Cyclone separator c. Strainer d. None of these
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3) Cyclones are used primarily for separating_________________? a. Solids b. Solids from fluids c. Liquids d. Solids from solids
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4) Which of the following is a batch sedimentation equipment ? a. Dust catcher b. Filter thickener c. Dry cyclone separator d. Rotary sprayer scrubber
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5) Shape factor for a cylinder whose length equals its diameter is_________________? a. 1.5 b. 0.5 c. 1.0 d. 2.0
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6) Filtration rate does not depend upon the________________? a. Pressure drop & area of filtering surface b. Resistance of the cake & the septum c. Properties of the cake & the filtrate d. None of these
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7) The operating speed of a ball mill should be ______________ the critical speed? a. Less than b. Much more than c. At least equal to d. Slightly more than
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8) Xanthates are used in the froth floatation process as a/an _______________________? a. Conditioner b. Frother c. Collector d. Activator
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9) Filtration should be stopped in a filter press, if the_________________? a. Cake becomes very dense b. Liquor stops flowing out to the discharge c. Filtration pressure rises suddenly d. Both B. & C.
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10) The reduction ratio for fine grinders is_____________? a. 5-10 b. 10-20 c. 20-40 d. As high as 100
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11) Which of the following is a coarse crusher ? a. Smooth roll crusher b. Toothed roll crusher c. Gyratory crusher d. Tube mill
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12) A _____________ mixer resembles a ball mill without balls? a. Banbury b. Pug mill c. Tumbling d. Pan
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13) In case of a plate and frame filter press, filtrate flow through the cake follows _______________ flow? a. Plug b. Turbulent c. Laminar d. None of these
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14) Grindability of a material does not depend upon its_____________________? a. Elasticity b. Hardness c. Toughness d. Size
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15) Work index is defined as the_________________? a. Gross energy (kWh/ton of feed) needed to reduce very large feed to such a size that 80% of the product passes through a 100 micron screen b. Energy needed to crush one tonne of feed to 200 microns c. Energy (kWh/ton of feed) needed to crush small feed to such a size that 80% of the product passes a 200 mesh screen d. Energy needed to crush one ton of feed to 100 microns
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16) Fibrous material is broken by a__________________? a. Roll-crusher b. Squirrel-cage disintegrator c. Ball mill d. Tube mill
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17) _____________ conveyors are also called scrapers? a. Apron b. Screw c. Helical flight d. Both B. & C.
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18) Sorting classifiers employing differential settling methods for separation of particles make use of the differences in their_________________? a. Particle sizes b. Densities c. Terminal velocities d. None of these
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19) __________ conveyor is the most suitable for short distance transportation of non-abrasive loose materials like garbage, grain, food wastes etc? a. Flight b. Screw c. Drag d. Belt
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20) Gelatinous solid (which plug the septum) can be filtered by a _____________ filter? a. Sparkler b. Plate and frame c. Vacuum leaf d. Pre-coat
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21) Sphericity of a cubical particle, when its equivalent diameter is taken as the height of the cube, is ________________ ? a. 0.5 b. 1 c. √2 d. √3
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22) For benefication of iron ore, the most commonly used method is______________? a. Flocculation b. Froth floatation c. Jigging & tabling d. None of these
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23) Basic slag is not ground in_________________? a. Jaw crushers b. Ball mills c. Compartment mills d. Tube mills
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24) Stamp mills are generally used for crushing__________________? a. Iron ores b. Gold ores c. Talc d. Diamond
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25) Which of the following minerals is not subjected to magnetic separation method ? a. Rutile b. Galena c. Chromite d. Siderite
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26) The work index in Bond’s law for crushing of solids has the following dimensions__________________? a. No units (dimensionless) b. kWh/ton c. kW/ton d. kWh.m1/2/ton
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27) Metallic wire mesh is used as a filtering medium for the separation of dust from dust laden gas in case of a/an________________? a. Air filter b. Bag filter c. Venturi scrubber d. Hydrocyclones
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28) All resistances during washing of cake _____________________? a. Increases b. Decreases c. Remain constant d. None of these
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29) Which of the following is the softest material ? a. Talc b. Feldspar c. Corundum d. Calcite
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30) Which of the following mechanical conveyors does not come under the division „scrapers‟ ? a. Ribbon conveyor b. Flight conveyor c. Bucket elevators d. Drag conveyor
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