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1) A sand mixture was screened through a standard 10-mesh screen. The mass fraction of the oversize material in feed, overflow and underflow were found to be 0.38, 0.79 and 0.22 respectively. The screen effectiveness based on the oversize is_________________? a. 0.50 b. 0.58 c. 0.68 d. 0.62
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2) ____________ conveyor is the most suitable for long distance transportation of cold, nonabrasive granular/irregular shape/fine materials? a. Bucket b. Belt c. Screw d. Apron
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3) ____________ mills fall in the category of tumbling mills ? a. Ball and pebble b. Rod and tube c. Compartment d. All A., B. & C.
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4) Pulverised coal passing through 200 mesh screen has a diameter of 0.074 mm (74 micron). The same passing through 50 mesh screen will have a dia of ____________ mm? a. 0.007 b. 0.30 c. 50 d. 0.014
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5) For Indian standard (IS) screens, the mesh number is equal to its aperture size expressed to the nearest deca-micron (0.01 mm). Aperture width of IS screen of mesh number 50 will be approximately _____________ microns? a. 5 b. 50 c. 500 d. 5000
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6) Which of the following is not categorised as a “mechanical operation”? a. Agitation b. Filtration c. Size enlargement d. Humidification
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7) Grinding characteristic of a material is given by its___________________? a. HGI b. Angle of repose c. Shatter index d. Abrasion index
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8) Ball mills and tube mills with flint or porcelain balls are used for size reduction of_______________? a. Asbestos b. Rubber c. Non-metallic ores d. Limestone
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9) Gravity settling process is not involved in the working of a________________? a. Hydrocyclone b. Classifier c. Dorr-thickener d. Sedimentation tank
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10) With increase in drum speed, in a rotary drum filter, the filtration rate_______________? a. Increases b. Increases linearly c. Decreases d. Is not affected
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11) Mixing of plastic solids is generally facilitated by___________________? a. Dispersion b. Mastication c. Kneading d. None of these
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12) The main size reduction operation in ultrafine grinders is_____________? a. Cutting b. Attrition c. Compression d. Impact
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13) Which of the following is not used as a filter medium in case of corrosive liquids? a. Nylon b. Glass cloth c. Metal cloth of monel or stainless steel d. Cotton fabric
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14) Which of the following is a pressure filter ? a. Leaf filter (Moore filter) b. Plate and flame filter c. Rotary drum filter d. Sand filter
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15) 200 mesh sieve size corresponds to _____________ microns? a. 24 b. 74 c. 154 d. 200
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16) Which of the following mineral dressing operations is termed as ‘comminution’? a. Panning b. Spiralling c. Tabling d. None of these
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17) Which of the following is not an industrial screening equipment ? a. Sharpies centrifuge b. Vibrating screen c. Grizzly d. Trommel
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18) Highly viscous liquids & pastes are agitated by________________? a. Propellers b. Turbine agitators c. Multiple blade paddles d. None of these
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19) Supporting legs of a plate and frame filter is normally made of________________? a. Stainless steel b. Cast iron c. High speed steel d. Wooden plank
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20) What is the usual value of angle of nip for crushing of ordinary rock in smooth steel crushing rolls? a. 16° b. 32° c. 40° d. 46°
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21) Size reduction of _____________ is accomplished in steam heated rollers and roll crushers? a. Resins b. Gums c. Hard rubber d. Waxes
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22) If radius of a batch basket centrifuge is halved & the r.p.m. is doubled, then the_________________? a. Linear speed of the basket is doubled b. Linear speed of the basket is halved c. Centrifugal force is doubled d. Capacity of centrifuge is increased
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23) Range of compressibility co-efficient of the commercial compressible cake obtained in filtration operation is_____________________? a. 0.01 to 0.1 b. 0.1 to 0.3 c. 0.2 to 0.8 d. 0.2 to 0.4
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24) Tabular bowl centrifuges as compared to disk bowl centrifuges___________________? a. Operate at higher speed b. Employ bowl of larger diameter c. Can’t be operated under pressure/vacuum d. Can’t be used for separation of fine suspended solids from a liquid
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25) _____________ Centrifuge is normally used in sugar mills? a. Tubular bowl b. Disc-bowl c. Suspended batch basket d. Perforated horizontal basket continuous
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26) Vertical transportation of materials can be done by a/an_______________? a. Apron conveyor b. Pneumatic conveyor c. Bucket elevator d. Both B. & C.
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27) The capacity of a pneumatic conveying system depends upon the ______________________? a. Bulk density of materials b. Pressure of the conveying air c. Diameter of the conveying line d. All A., B. and C.
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28) Which of the following parts of a jaw crusher is subjected to maximum wear and tear during its operation ? a. Check plates b. Jaw plates c. Toggles d. Crush shaft
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29) The term ‘angle of nip’ is concerned with the operation of the ____________ crushers? a. Jaw b. Roll c. Gyratory d. None of these
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30) Which of the following gives the work required for size reduction of coal to -200 mesh in a ball mill most accurately? a. Rittinger’s law b. Kick’s law c. Bond’s law d. None of these
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