Mechanical Operations

111. Filtration of water in a paper mill is done by a/an _________ filter.

1. Open sand
2. Plate and frame
3. Vacuum leaf
4. Sparkler

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112. Filtration operation carried out by continuous increase of the inlet pressure of slurry, is called the _________ filtration.

1. Constant rate
2. Varying pressure
3. Varying rate
4. Constant pressure

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113. Filtration rate does not depend upon the

1. Pressure drop & area of filtering surface
2. Resistance of the cake & the septum
3. Properties of the cake & the filtrate
4. None of these

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114. Filtration rate through a filter cake is proportional to (where, S = filtering surface R = specific cake resistance μ = viscosity of the filtrate)

1. S
2. 1/R
3. 1/μ
4. All (A), (B) & (C)

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115. Filtration should be stopped in a filter press, if the

1. Cake becomes very dense
2. Liquor stops flowing out to the discharge
3. Filtration pressure rises suD⁵enly
4. Both (B) & (C)

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116. Float and sink test determines the possibility of cleaning of coal by a process based on the

1. Gravity separation
2. Wettability
3. Particle shape
4. None of these

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117. Flow of filtrate through the cake in a plate and frame filter press is best described by the _________ equation.

1. Kozeny-Carman
2. Hagen-Poiseuille's
3. Fanning's
4. Kremser

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118. Fluid energy mill comes in the category of

1. Grinder
2. Crusher
3. Cutter
4. Ultrafine grinder

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119. Fluid medium used in the classification technique of mineral beneficiation is

1. Air
2. Water
3. Either (A) or (B)
4. Neither (A) nor (B)

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120. For a cyclone of diameter 0.2 m with a tangential velocity of 15 m/s at the wall, the separation factor is

1. 2250
2. 1125
3. 460
4. 230

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