Mechanical Operations

101. Equivalent diameter of a particle is the diameter of the sphere having the same

1. Ratio of surface to volume as the actual volume
2. Ratio of volume to surface as the particle
3. Volume as the particle
4. None of these

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102. Feed size of ≥ 25 cms can be accepted by

1. Ball mill
2. Rod mill
3. Fluid energy mill
4. Jaw crusher

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103. Fibrous material is broken by a

1. Roll-crusher
2. Squirrel-cage disintegrator
3. Ball mill
4. Tube mill

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104. Fick's law relates to

1. Energy consumption
2. Final particle size
3. Feed size
4. None of these

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105. Filter aid is used to

1. Increase the rate of filtration
2. Decrease the pressure drop
3. Increase the porosity of the cake
4. Act as a support base for the septum

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106. Filter aids like asbestos, kieselguhr, diatomaceous earth etc. are used to increase the porosity of the final filter cake & reducing the cake resistance during filtration. Filter aid is

1. AD⁵ed to the feed slurry
2. Pre-coated on the filter medium prior to filtration
3. Separated from the cake by dissolving solids or by burning it off
4. All 'a', 'b' & 'c'

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107. Filter medium resistance is important during the _________ of filtration.

1. Early stages
2. Final stages
3. Entire process
4. None of these

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108. Filter medium resistance is that offered by the

1. Filter cloth
2. EmbeD⁵ed particles in the septum
3. Filter cloth and the embeD⁵ed particle collectively
4. None of these

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109. Filtrate flow rate in case of a rotary drum vacuum filter (in which R_m < < Rc) is proportional to _________ and the cycle time (where, μ = filtrate viscosity R_m = filter medium resistance Rc = cake resistance).

1. √μ
2. 1/√μ
3. 1/μ
4. 1/μ2

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110. Filtration capacity of a rotary drum vacuum filter depends upon the

1. Cake thickness
2. Characteristics of the feed slurry
3. Both (A) & (B)
4. Neither (A) nor (B)

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