0% 0 Mechanical Operations Quiz 7 1 / 50 The main differentiation factor between tube mill and ball mill is the _____? Final product size Length to diameter ratio Operating speed Size of the grinding media 2 / 50 To produce talcum powder, use_______? Ball mill Pin mill Jet mill Hammer mill 3 / 50 The mechanism of size reduction by a hammer mill is by impact and attrition between the_________? Feed particles Both A. and B. Grinding element & the housing Neither A. nor B. 4 / 50 The opening of a 200 mesh screen (Taylor series) is___________? 74 milli-microns 0.0074 mm 0.0074 cm 0.0047 cm 5 / 50 The main size reduction operation in ultrafine grinders is______? Impact Cutting Attrition Compression 6 / 50 The most suitable equipment used to devulcanise rubber scrap and to make water dispersion & rubber solution is a ___________? Boundary mixer None of these Sharpies centrifuge Propeller agitator 7 / 50 The study on washability of coal is done by using the ______ technique? Heavy media separation Elutriation Tabling None of these 8 / 50 The sphericity of a solid particle of cubical shape is _____? (?/6)1/2 ? ?/3 (?/6)1/3 9 / 50 There is practically no alternative/competitor to __________ in the beneficiation treatment of sulphide ores? Jigging Classification Froth floatation Tabling 10 / 50 The most suitable equipment for removing the fine dust particle (< 1 micron dia.) from air below its dew point will be a/an_______? Bag filter Electrostatic precipitator Wet scrubber Cyclone separator 11 / 50 The ratio of the area of openings in one screen (Taylor series) to that of the openings in the next smaller screen is__________? ?2 1.5 None of these 1 12 / 50 To get ultrafine particles, the equipment used is a __________? Fluid energy mill Rod mill Hammer crusher Ball mill 13 / 50 The porosity of a compressible cake is _______? Minimum at the upstream face Minimum at the filter medium Same throughout the thickness of cake Maximum at the filter medium 14 / 50 The work index in Bond?s law for crushing of solids has the following dimensions___________? No units (dimensionless) kW/ton kWh.m1/2/ton kWh/ton 15 / 50 The operating speed of a ball mill should be _______ the critical speed? At least equal to Less than Slightly more than Much more than 16 / 50 Traces of liquid tar fog present in coke oven gas is separated using______? Strainer None of these Electrostatic precipitator Cyclone separator 17 / 50 The important dimensional group involved in the power requirement calculation in mixing operation is the ______ number? Reynold?s Neither A. nor B. Froude Both A. & B. 18 / 50 The material is crushed in a gyratory crusher by the action of___________? Compression Impact Cutting Attrition 19 / 50 The specific cake resistance for incompressible sludges is (where ?P = pressure drop over cake)___________? ? ?P ? 1/ ?P Independent of ?P ? ??P 20 / 50 The specific cake resistance for compressible sludges is a function of the pressure drop___________? Overall Over cake Over medium None of these 21 / 50 The specific surface of spherical particles is given by (where D and ? are diameter and density of particle) ? 6/D.? 12/D.? 4/D.? 2/D.? 22 / 50 The process opposite to ?dispersion? is termed as the_____? Sedimentation None of these Flocculation Filtration 23 / 50 The unit of specific cake resistance is________? cm/gm2 gm/cm2 cm/gm gm/gm 24 / 50 The unit of filter medium resistance is_________? cm/gm-1 gm/cm-1 cm-1 gm-1 25 / 50 The most suitable equipment for the transportation of 200 mesh size particles is a ________? Belt conveyor Bucket elevator Screw conveyor Pneumatic conveyor 26 / 50 The maximum slope of a belt conveyor can be_______? 15? 30? 60? 45? 27 / 50 The inlet pressure in a constant rate filtration______? Increases continuously None of these Remains constant Decreases gradually 28 / 50 The reduction ratio for grinders is defined as (where, Df and Dp are average diameters of feed and product respectively) ? Df ? Dp None of these Df/Dp Dp/Df 29 / 50 To remove very small amount of tiny solid impurities from liquid, we use a_______? Vacuum filter Coagulant Centrifugal filter Pressure filter 30 / 50 The sphericity of a cylinder of 1 mm diameter and length 3 mm is__________? 0.78 0.9 0.6 0.5 31 / 50 The ratio of the actual mesh dimension of Taylor series to that of the next smaller screen is________? 2 ?3 1.5 ?2 32 / 50 Toothed roll crushers achieve size reduction by_____? Neither A. nor B. Both A. & B. Tearing (shear) and compression Impact and attrition 33 / 50 The grinding in a hammer crusher takes place due to the________? Neither A. nor B. Both A. & B. Impact Attrition 34 / 50 The resistance offered by the filter used in a bag filter is proportional to (where, c = dust concentration, and s = particle size)? c/s s . c s/c 1/s . c 35 / 50 The most efficient equipment for the removal of sub-micronic dust particles from blast furnace gas is the___________? Gravity settling chamber Cyclone separator Electro-static precipitator Venturi atomiser 36 / 50 The optimum moisture content in solids to be crushed/ground ranges from ________ percent? 10 to 15 15 to 20 3 to 4 8 to 10 37 / 50 The reduction ratio for fine grinders is______? 20-40 10-May 20-Oct As high as 100 38 / 50 The specific surface of spherical particles is proportional to (where, Dp = diameter of particle)? 1/Dp D2 1/D2p Dp 39 / 50 The most common filter aid is__________? Diatomaceous earth Calcium silicate Silica gel Sodium carbonate 40 / 50 The value of ?angle of nip? is generally about___________? 32? 64? 16? 52? 41 / 50 The filtrate flow rate in constant pressure filtration_____? May increase or decrease; depends on the pressure Continuously increases Continuously decreases Remain constant throughout 42 / 50 The value of work index does not change materially from one equipment to another. If the value of work index determined for close circuit grinding is Wi, then the same for open circuit grinding will be__________? 3.34 Wi 0.5 Wi 1.34 Wi Wi 43 / 50 To get a fine talc powder from its granules, the equipment used is______? Gyratory crusher Ball mill Jaw crusher Roller crusher 44 / 50 Trommels employ ______ for screening of materials? Punched plate Fibrous cloth Woven wire screen None of these 45 / 50 The most suitable filter for the removal of very small amount of precipitate from very large volumes of water is the ______ filter? Vacuum Rotary Plate & frame Sand 46 / 50 The power number for a stirred tank becomes constant at high Reynolds number. In this limit, the variation of power input with impeller rotational speed (N) is proportional to_____? N3 N? N1 N2 47 / 50 The speed of a rotary drum vacuum filter may be about ______ rpm? 1 50 100 500 48 / 50 The process by which fine solids is removed from liquids is termed as _______? Sedimentation Decantation Flocculation Classification 49 / 50 To remove dirt from the flowing fluid, we use a ______? Gravity settler Clarifier Strains Coagulant 50 / 50 The term ?angle of nip? is concerned with the operation of the _____ crushers? None of these Gyratory Jaw Roll Provide Your Information Your score is The average score is 0% LinkedIn Facebook Twitter 0% Restart quiz Send feedback Share on facebook Facebook Share on twitter Twitter Share on whatsapp WhatsApp PrevMechanical Operations Quiz 6 Mechanical Operations Quiz 8Next
