Q.1

Moore filter is a __________ filter.

  • leaf
  • press
  • rotary
  • sand
Q.2

mesh screen meansopenings per

  • cm2
  • cm
  • inch
  • inch2
Q.3

__________ is the most commonly used 'filter aid'.

  • Diatomaceous earth
  • Fuller's earth
  • Vermiculite
  • Semi-plastic clay
Q.4

Gravity settling process is not involved in the working of a

  • hydrocyclone
  • classifier
  • dorr-thickener
  • sedimentation tank
Q.5

Sulphuric acid mist is arrested by using a __________ scrubber.

  • packed wet
  • hollow wet
  • venturi
  • co-current
Q.6

For a non-spherical particle, the sphericity

  • is defined as the ratio of surface area of a sphere having the same volume as the particle to the actual surface area of the particle.
  • has the dimension of length.
  • is always less than 1.
  • is the ratio of volume of a sphere having the same surface area as the particle to the actual volume of the particle.
Q.7

Shape factor for a cylinder whose length equals its diameter is

  • 1.5
  • 0.5
  • 1.0
  • 2.0
Q.8

Screen capacity is not a function of

  • its openings size.
  • screening mechanism.
  • screening surface.
  • atmospheric humidity.
Q.9

Coal is finally pulverised tomesh size for burning in boilers by a

  • hammer crusher
  • ball mill
  • roll crusher
  • gyratory crusher
Q.10

__________ are used for the separation of coarse particles from a slurry of fine particles.

  • Thickeners
  • Classifiers
  • Hydrocyclones
  • Decanters
Q.11

Sphericity of a cubical particle, when its equivalent diameter is taken as the height of the cube, is

  • 0.5
  • 1
  • 2
  • 3
Q.12

Froth floatation is the most suitable for treating

  • iron ores
  • sulphide ores
  • quartzite
  • none of these
Q.13

The main size reduction operation in ultrafine grinders is

  • cutting
  • attrition
  • compression
  • impact
Q.14

In washing type plate and frame filter press, the ratio of washing rate to the final filtrate rate is

  • 4
  • 1/4
  • 1
  • 1/2
Q.15

In case of a hammer crusher, the

  • feed may be highly abrasive (Moh's scale >5).
  • minimum product size is 3 mm.
  • maximum feed size may be 50 mm.
  • rotor shaft carrying hammers can be vertical or horizontal.
Q.16

Dust laden air can be purified using a

  • cyclone separator
  • bag filter
  • gravity settler
  • tubular centrifuge
Q.17

Which of the following is a vacuum filter ?

  • Filter press
  • Rotary disc filter
  • Batch basket centrifuge
  • Tank filter (Nutsch filter)
Q.18

Pine oil used in froth floatation technique acts as a/an

  • collector
  • modifier
  • frother
  • activator
Q.19

Crushing efficiency is the ratio of the

  • surface energy created by crushing to the energy absorbed by the solid.
  • energy absorbed by the solid to that fed to the machine.
  • energy fed to the machine to the surface energy created by crushing.
  • energy absorbed by the solid to the surface energy created by crushing.
Q.20

Fibrous material is broken by a

  • rollcrusher
  • squirrel-cage disintegrator
  • ball mill
  • tube mill
Q.21

__________ is the most suitable for compounding rubber and plastic solids.

  • Banbery mixer
  • Pan mixer
  • Pug mill
  • Charge can mixer
Q.22

Ball mill is used for

  • crushing
  • coarse grinding
  • fine grinding
  • attrition
Q.23

In case of a hammer crusher,

  • crushing takes place by impact breaking.
  • maximum acceptable feed size is 30 cms.
  • reduction ratio can be varied by adjusting the distance from cage to hammers.
  • all (a), (b) and (c).
Q.24

Ball mills and tube mills with flint or porcelain balls are used for size reduction of

  • asbestos
  • rubber
  • non-metallic ores
  • limestone
Q.25

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
Q.26

In case of a ball mill,

  • coarse feed requires a larger ball.
  • fine feed requires a larger ball.
  • operating speed should be more than the critical speed.
  • none of these
Q.27

Short distance transportation of grain, gravel, sand, ash, asphalt etc. is done by using a __________ conveyor.

  • flight
  • slat or drag
  • ribbon
  • screw
Q.28

Rittinger's number designates the new surface created per unit mechanical energy absorbed by the material being crushed. Larger value of Rittinger's number of a material indicates its

  • easier grindability
  • poor grindability
  • high power consumption in grinding
  • none of these
Q.29

Cement clinker is reduced to fine size by a

  • roll crusher
  • ball mill
  • tube mill
  • hammer mill
Q.30

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

  • ratio of surface to volume as the actual volume.
  • ratio of volume to surface as the particle.
  • volume as the particle.
  • none of these.
Q.31

If dp is the equivalent diameter of a non-spherical particle, Vp its volume and sp its surface area, then its sphericity is Φs is defined by

  • Φs = 6 Vp/dp sp
  • Φs = Vp/dp sp
  • Φs = 6 dp Sp/Vp
  • Φs = dp Sp/Vp
Q.32

Energy consumed for crushing one ton of material ranges from __________ kWh.

  • 0.01 to 0.1
  • 0.5 to 1.5
  • 2 to 3.5
  • 4 to 5.
Q.33

Capacity (in tons/hr) of jaw/gyratory crusher is equal to (where, L = length of the receiving opening, cm S = greater width of the discharge opening, cm)

  • 0.01 L.S
  • 0.087 L.S
  • L.S
  • L.S/0.087
Q.34

The crushed material received for separation is called feed or

  • tailing
  • heading
  • concentrate
  • middling
Q.35

Power required to drive a ball mill with a particular ball load is proportional to (where, D = diameter of ball mill )

  • D
  • 1/D
  • D2.5
  • 1/D2.5
Q.36

For transporting pasty material, one will use a/an

  • apron conveyor
  • belt conveyor
  • screw colaveyor
  • bucket elevator
Q.37

Where the density difference of the two liquid phase to be separated is very small (as in milk cream separator), the most suitable separator is a

  • disc bowl centrifuge.
  • sharpies supercentrifuge.
  • batch basket centrifuge.
  • sparkler filter.
Q.38

Vacuum is applied in __________ zone, in case of a general type continuous rotary drum vacuum filter.

  • filtering
  • washing
  • drying
  • all (a), (b) & (c)
Q.39

For spheres, volume shape factor is given by

  • π(=A/D2)
  • 2π(=2A/D2)
  • π/6(=V/D3)
  • AD/V
Q.40

Pick out the wrong statement.

  • Recycled coarse material to the grinder by a classifier is termed as circulating load.
  • Wear and tear in wet crushing is more than that in dry crushing of materials.
  • Size enlargement (opposite of size reduction) is not a mechanical operation.
  • A 'dust catcher' is simply an enlargement in a pipeline which permits the solids to settle down due to reduction in velocity of the dust laden gas.
Q.41

A tube mill compared to a ball mill

  • has a higher length/diameter ratio.
  • produces a coarser product.
  • has a higher diameter/length ratio.
  • uses much larger balls.
Q.42

Which of the follwoing mechanical conveyors does not come under the division 'scrapers' ?

  • Ribbon conveyor
  • Flight conveyor
  • Bucket elevators
  • Drag conveyor.
Q.43

Which of the following agitators having a large blade area, rotating at slow speed is used for mixing high viscosity liquids ( >centipoise) ?

  • Propeller
  • Helical screw
  • Flat blade turbine
  • Curved blade turbine
Q.44

Trommels separate a mixture of particles depending on their

  • size
  • density
  • wettability
  • electrical & magnetic properties
Q.45

__________ is defined as the geometric mean of the relative rejections and the relative recoveries of two minerals.

  • Separation efficiency
  • Selectivity index
  • Concentration ratio
  • none of these
Q.46

Which of the follwoing mechanical conveyors does not come under the division 'scrapers' ?

  • Ribbon conveyor
  • Flight conveyor
  • Bucket elevators
  • Drag conveyor.
0 h : 0 m : 1 s