- A. Apron conveyor
- B. Belt conveyor
- C. Screw conveyor
- D. Pneumatic conveyor
Mechanical Operations
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Which is the most suitable conveyor for transportation of sticky material?
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Length/diameter ratio of a ball mill is_____.
- A. 1.5
- B. 1
- C. < 1
- D. > 1
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Rod mills employed for grinding_____.
- A. Employ a steel shell having L/D ratio of 1.5 to 3.0
- B. Is useful for handling sticky materials
- C. Employ steel rods of 2-12 cms diameter extending over full length of the mill
- D. All of the above
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Particle size range in which dust catcher (gravity settling chamber) works most effectively and efficiently is _____ microns.
- A. < 5
- B. 10 to 25
- C. < 74
- D. > 1000
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The maximum slope of a belt conveyor can be_____.
- A. 15°
- B. 30°
- C. 45°
- D. 60°
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Grinding efficiency of a ball mill is of the order of ______ percent.
- A. 1-5
- B. 40-50
- C. 75-80
- D. 90-95
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Filter aid is used to_____.
- A. Increase the rate of filtration
- B. Decrease the pressure drop
- C. Increase the porosity of the cake
- D. Act as a support base for the septum
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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 ‘industries’
- C. The equipment used for the removal of traces of solids from a liquid is called a classifier
- D. Size enlargement is a mechanical operation exemplified by medicinal tablet making
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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
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Filtration rate through a filter cake is proportional to (where, S = filtering surface R = specific cake resistance μ = viscosity of the filtrate)
- A. S
- B. 1/R
- C. 1/μ
- D. All of the above