Description : Separation of solid particles based on their densities is called (A) Sizing (B) Sorting (C) Clarification (D) Dispersion
Last Answer : (B) Sorting
Description : Sorting classifiers employing differential settling methods forseparation of particles make use of the differences in their (A) Particle sizes (B) Densities (C) Terminal velocities (D) None of these
Last Answer : (C) Terminal velocities
Description : Sedimentation on commercial scale occurs in (A) Classifiers (B) Thickeners (C) Rotary drum filters (D) Cyclones
Last Answer : (C) Rotary drum filters
Description : The capacity of a classifier in 'tons of solid/hr' is given by (where, A = cross-sectional area in m2 , V = rising velocity of fluid in m/sec, S = percentage of solids in the suspension by volume, ρ = density of solids in kg/m3 ) (A) 3.6 AVS.ρ (B) 3.6 A.V.ρ (C) 3.6 A.S. ρ (D) 3.6 AVS/ρ
Last Answer : (A) 3.6 AVS.ρ
Description : Separation of particles of various sizes, shapes and densities by allowing them to settle in a fluid is called (A) Classification (B) Froth floatation (C) Thickening (D) Clarification
Last Answer : (A) Classification
Description : The terminal velocity of a solid spherical particle falling through a stationary fluid mass in the Stoke's law range is proportional to the (A) Inverse of fluid viscosity (B) Square of particle size (C) Difference in the densities of the particle & fluid (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : What does gases low densities show about the distance between gas particles?
Last Answer : A low-density gas would have molecules that are farther apartand fewer in numbers per unit volume.
Description : Which of the following laws best describes the statement: The members of an homologous (pron: ho-MOL-eh-gus) pair of genes are separated during meiosis (pron: my-O-sis) of reproductive cells so that ... law of independent assortment c) law of filial (pron: FILL-ee-al) generation d) law of sorting
Last Answer : ANSWER: A -- LAW OF SEGREGATION
Description : Jigging is a technique by which different particles can be (A) Separated by particle size (B) Separated by particle density (C) Separated by particle shape (D) Mixed
Last Answer : (A) Separated by particle size
Description : How do water relative densities as a solid and a liquid differ from most other substances?
Last Answer : The solid phase of water (ice) is less dense than its liquid phase, therefore ice floats on liquid water. For other substances, the solid phase is most dense and it sinks in its liquid.
Description : Gravity settling process is not involved in the working of a (A) Hydrocyclone (B) Classifier (C) Dorr-thickener (D) Sedimentation tank
Last Answer : (A) Hydrocyclone
Description : Pick out the wrong statement. (A) Recycled coarse material to the grinder by a classifier is termed as circulating load (B) Wear and tear in wet crushing is more than that in dry crushing of ... a pipeline which permits the solids to settle down due to reduction in velocity of the dust laden gas
Last Answer : (C) Size enlargement (opposite of size reduction) is not a mechanical operation
Description : Pick out the wrong statement. (A) Close circuit grinding is more economical than open circuit grinding (B) Cod oil, beef tallow or aluminium stearates are used as grinding aids in cement ... is called a classifier (D) Size enlargement is a mechanical operation exemplified by medicinal tablet making
Last Answer : (C) The equipment used for the removal of traces of solids from a liquid is called a classifier
Description : Which of the following is not a wet classifier? (A) Sharpies super-centrifuge (B) Hydrocyclones (C) Dorr Oliver rake classifier (D) None of these
Last Answer : (D) None of these
Description : Close circuit grinding by a ball mill with air sweeping employs a (A) Classifier (B) Cyclone separator between mill & classifier (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) & (B)
Description : __________ employs a set of screen across a flow channel for the separation of dirt/rust from a flowing liquid stream. (A) Thickener (B) Classifier (C) Strainer (D) Clarifier
Last Answer : (C) Strainer
Description : Pick out the wrong statement pertaining to leaching. (A) Fine solids cannot be leached in a Pachuca tank (B) Door classifier can be used for leaching of coarse solids (C) Vegetable seeds can be ... , Rotocel or Kennedy extractor (D) Very high temperature is not needed for the leaching of sugar beet
Last Answer : (A) Fine solids cannot be leached in a Pachuca tank
Description : Hydro-cyclone is a (A) Crusher (B) wet classifier (C) Dry classifier (D) Magnetic separator
Last Answer : (B) wet classifier
Description : Gravity settling tanks/porous filters are used to remove particles larger than
Last Answer : Gravity settling tanks/porous filters are used to remove particles larger than A. `2 mum ` B. `50 mum` C. `20 mum` D. `10 mum`
Description : Ivanowsky, Beijerinck and Reed all began studies with particles smaller than the filters they were working with. This began the study of _____. a. measles b. viruses c. prions d. bacteria
Last Answer : b. viruses
Description : Tabling process used for separating two materials of different densities by passing the dilute pulp over a table/deck, which is inclined from the horizontal surface at an angle of about (A) 1 to 2° (B) 2 to 5° (C) 5 to 10° (D) 10 to 15°
Last Answer : (B) 2 to 5°
Description : If a force greater than that of gravity is used to separate solids & fluidsof different densities, the process is termed as the (A) Sedimentation (B) Flocculation (C) Dispersion (D) Centrifugation
Last Answer : (D) Centrifugation
Description : The range of a particular Rotameter can be increased by (A) Use of floats of different densities (B) No means (C) Increasing the diameter of the float (D) Decreasing the diameter of the float
Last Answer : (A) Use of floats of different densities
Description : How do you separate substances with different densities?
Last Answer : Feel Free to Answer
Description : Cherapunji receives more rainfall than Shillong because: (a) the former is nearer to the sea (b) the air of different densities and temperature tends to converge towards Cherapunjl from ... Cherapunji is located on the windward side (d) convective precipitation brings more rain at Cherapunji
Last Answer : Ans: (b)
Description : When a beam of light travels through media of two different densities, if theangle of incidence isgreater than the critical angle, _______ occurs. A) reflection B) refraction C) incidence D) criticism
Last Answer : reflection
Description : During drying of a solid, the critical moisture content increases with (A) Decreased drying rate (B) Increased thickness of the solid (C) Increased drying rate (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : The drying time between fixed moisture contents within the 'constant rate period' is proportional to (assuming that drying occurs from all surfaces of the solid) (where, T = thickness of the solid). (A) √T (B) T (C) T 1.5 (D) T
Last Answer : (B) T
Description : For __________ drying, the effects of velocity, temperature and humidity of the gas and the thickness of the solid are the same. (A) Unsaturated surface (B) Constant rate (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) and (B)
Description : The drying time between fixed moisture content within diffusion controlled 'falling rate period' is proportional to (assuming that drying occurs from all surfaces of the solid) (where, T = thickness of the solid). (A) √T (B) T (C) T 2 (D) T
Last Answer : (C) T
Description : . In a linear polymer, the monomeric units are linked together to form long straight chains. The cross linked or branched chain polymers compared to linear polymers have higher (A) Densities (B) Melting point (C) Tensile strength (D) Hardness, rigidity & brittleness
Last Answer : (D) Hardness, rigidity & brittleness
Description : Electrostatic separation of minerals from each other is based on their differences in the following property. (A) Densities (B) Magnetic permeabilities (C) Electrical conductivities (D) Hardness
Last Answer : (C) Electrical conductivities
Description : The same volume of all gases is representative of their (A) Specific gravities (B) Densities (C) Gas characteristic constants
Last Answer : Option D
Description : The solid and liquid can be separated by the process of:
Last Answer : Filtration
Description : Separation of materials of the same density based on their sizes by using then-different rates of flow is called (A) Sorting (B) Sizing (C) Flocculation (D) Elutriation
Last Answer : (B) Sizing
Description : Cyclones are used primarily for separating (A) Solids (B) Solids from fluids (C) Liquids (D) Solids from solids
Last Answer : (B) Solids from fluids
Description : A circular solid of uniform thickness 20 mm, radius 200 mm and mass 20 kg, is used as a flywheel. If it rotates at 600 rpm, the kinetic energy of the flywheel, in joules is 1. 395 2. 790 3. 1580 4. 3160
Last Answer : 2. 790
Description : Ultra centrifuges are used for the separation of __________ solid particles. (A) Coarse (B) Fine (C) Colloidal (D) Dissolved
Last Answer : (C) Colloidal
Description : Pick out the wrong statement. (A) Gape is the greatest distance between the crushing surfaces or the jaws (B) The angle of nip (2α) is the angle between roll faces at the level where they will ... Reduction ratio is the ratio of the maximum size of the particles in the feed to that in the product
Last Answer : (C) Crushing efficiency is the ratio of the energy absorbed by the solid to the surfaces energy created by crushing
Description : Which of the following is not accomplished by agitation of liquids in agitators? (A) Dispersing gas in liquid (B) Blending of immiscible liquids (C) Dispersing immiscible liquid in form of emulsion (D) Suspending solid particles
Last Answer : (B) Blending of immiscible liquids
Description : A screen is said to be blinded, when the (A) Over-sizes are present in undersize fraction (B) Under-sizes are retained in oversize fraction (C) Screen is plugged with solid particles (D) Screen capacity is abruptly increased
Last Answer : (C) Screen is plugged with solid particles
Description : Solid particles separation based on the difference in their flow velocities through fluids is termed as the (A) Clarification (B) Classification (C) Elutriation (D) Sedimentation
Last Answer : (B) Classification
Description : Separation of a suspension or slurry into a supernatant clear liquid (free from particles) and a thick sludge containing a high concentration of solid is called (A) Classification (B) Sedimentation (C) Clarification (D) Decantation
Last Answer : (B) Sedimentation
Description : Number of particles in a crushed solid sample is given by (where, m = mass of particles in a sample, Vp = volume of one particle, ρ= density of particles) (A) m/ρ . Vp (B) m . ρ/Vp (C) m . Vp /ρ (D) Vp /m . ρ
Last Answer : (A) m/ρ . Vp
Description : Pick out the wrong statement. (A) The binary diffusivity in liquids is of the order of 10 -5 cm2 /sec (B) Molecular diffusion in solid is much faster than that in liquids ( ... Poiseuille's law, the permeability decreases with increase in temperature for flow of a gas through a given capillary
Last Answer : (B) Molecular diffusion in solid is much faster than that in liquids
Description : A globe valve is the most suitable for applications, in which (A) Fluid flow control is required (B) Fluid contains dispersed solid particles (C) Valve is required to be either fully open or fully closed (D) One way flow is required
Last Answer : (A) Fluid flow control is required
Description : The uniformity of a gas fluidised bed depends upon the __________ of the solid particles. (A) Size (B) Surface properties (C) Both (A) and (B) (D) Neither (A) nor (B)
Description : Which of the following is not an advantage of fluidisation from transferoperation point of view? (A) Intimate contact of the fluid with all parts of the solid particles (B) Lower fluid pumping power requirement (C) Minimisation of temperature variation (D) Prevention of particle segregation
Last Answer : (B) Lower fluid pumping power requirement
Description : Coal washing waste water containing about 3% suspended solids (comprising of clay, slate, stone etc.) is treated for solid particles removal (A) By chemical coagulation (B) In sedimentation tanks equipped with mechanical scrapper (C) In vacuum filter (D) In clarifiers
Last Answer : (B) In sedimentation tanks equipped with mechanical scrapper
Description : Sooty and sulphurous smog formed due to combustion of fossil fuels particularly in winter, continues throughout the day and night. When the moist atmospheric air's water vapor condenses on the solid particles of smoke thereby ... B) Irritation in eyes (C) Respiratory trouble (D) All (A), (B) and (C)