Q.1

Arrange the following size reduction equipment in the decreasing order of the average particle size produced by each of them.

  • Jaw crusher, Ball mill, Fluid energy mill
  • Ball mill, Jaw crusher, Fluid energy mill
  • Fluid energy mill, Jaw crusher, Ball mill
  • Fluid energy mill, Ball mill, Jaw crusher
Q.2

For Indian standard (IS) screens, the mesh number is equal to its aperture size expressed to the nearest deca-micron (0.mm). Aperture width of IS screen of mesh numberwill be approximately __________ microns.

  • 5
  • 50
  • 500
  • 5000
Q.3

__________ mills are termed as disintegrators.

  • Cage
  • Compartment
  • Pebble
  • All tumbling
Q.4

Size reduction of ice and gypsum can be accomplished suitably by a __________ crusher.

  • Blake jaw
  • toothed roll
  • gyratory
  • none of these.
Q.5

Carbon black is pulverised in a

  • hammer crusher
  • ball mill
  • roll crusher
  • gyratory crusher
Q.6

Screen capacity is expressed in terms of

  • tons/hr
  • tons/ft2
  • both (a) & (b)
  • tons/hr-ft2
Q.7

Solid particles of different densities are separated by

  • filters
  • thickness
  • cyclones
  • sorting classifier
Q.8

With increase in the capacity of screens, the screen effectiveness

  • remains unchanged
  • increases
  • decreases
  • decreases exponentially
Q.9

Which of the following achieves the least reduction ratio for a given feed size?

  • Jaw crusher
  • Roll crusher
  • Cone crusher
  • Gyratory crusher
Q.10

Which of the following is not a non-metalliferous mineral?

  • Calcite
  • Fluorspar
  • Quartz
  • Cassiterrite
Q.11

Filter medium resistance is important during the __________ of filtration.

  • early stages.
  • final stages.
  • entire process.
  • none of these.
Q.12

In classification, particles are said to be equal settling, if they have the same terminal velocities in the

  • different fluids
  • same fluid
  • same field of force
  • both (b) and (c)
Q.13

Mixer used for rubber compounding is

  • mixer-extruder
  • banbury internal mixer
  • muller mixer
  • pug mill
Q.14

Filtration rate does not depend upon the

  • pressure drop & area of filtering surface.
  • resistance of the cake & the septum.
  • properties of the cake & the filtrate.
  • none of these.
Q.15

Which of the following is a batch sedimentation equipment ?

  • Dust catcher
  • Filter thickener
  • Dry cyclone separator
  • Rotary sprayer scrubber.
Q.16

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

  • classification
  • sedimentation
  • clarification
  • decantation
Q.17

Reduction ratio of crushers is the

  • ratio of feed opening to discharge opening.
  • ratio of discharge opening to feed opening.
  • determining factor for minimum dia of the feed and the product.
  • none of these.
Q.18

Mechanical conveyors which push the material along an endless trough or tube are called scrappers. Which of the following conveying equipments comes under the category of 'scrappers' ?

  • Bucket conveyor
  • Flight conveyor
  • Screw conveyor
  • Both (b) and (c)
Q.19

mesh seive size corresponds to __________ microns.

  • 24
  • 74
  • 154
  • 200
Q.20

Supporting legs of a plate and frame filter is normally made of

  • stainless steel
  • cast iron
  • high speed steel
  • wooden plank
Q.21

A filter press is

  • a batch filter.
  • not suitable, if the liquid is the main product.
  • having prohibitively high maintenance cost.
  • not suitable for wide range of materials under varying operating conditions of cake thickness and pressure.
Q.22

Xanthates are used in the froth floatation process as a/an

  • conditioner
  • frother
  • collector
  • activator
Q.23

The most efficient equipment for the removal of sub-micronic dust particles from blast furnace gas is the

  • venturi atomiser
  • gravity settling chamber
  • electro-static precipitator
  • cyclone separator
Q.24

The filtrate flow rate in constant pressure filtration

  • continuously increases.
  • continuously decreases.
  • remains constant throughout.
  • may increase or decrease ; depends on the pressure.
Q.25

A screen is said to be blinded, when the

  • oversizes are present in undersize fraction.
  • undersizes are retained in oversize fraction.
  • screen is plugged with solid particles.
  • screen capacity is abruptly increased.
Q.26

What is the critical rotation speed in revolutions per second, for a ball mill of 1.2 m diameter charged withmm dia balls ?

  • 0.5
  • 1.0
  • 2.76
  • 0.66
Q.27

During agitation of liquids, power consumption during laminar flow is not proportional to the

  • density of the liquid
  • viscosity of the liquid
  • cube of impeller diameters
  • square of rotational speed.
Q.28

As particle size is reduced

  • screening becomes progressively more difficult.
  • screening becomes progressively easier.
  • capacity and effectiveness of the screen is increased.
  • none of these.
Q.29

During the washing of cake

  • all the resistances are constant.
  • filter medium resistance increases.
  • filter medium resistance decreases.
  • cake resistance decreases.
Q.30

In constant pressure filtration,

  • resistance decreases with time
  • rate of filtration is constant
  • rate of filtration increases with time
  • rate of filtration decreases with time
Q.31

Which of the following oxides is not present in hematite iron ore?

  • Titanium oxide
  • Calcium oxide
  • Cobalt oxide
  • Manganese oxide
Q.32

To get a fine talc powder from its granules, the equipment used is

  • roller crusher
  • ball mill
  • jaw crusher
  • gyratory crusher
Q.33

A fluid energy mill is used for

  • cutting
  • grinding
  • ultragrinding
  • crushing
Q.34

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

  • gravity separation
  • wettability
  • particle shape
  • none of these
Q.35

Dispersion of a gas through liquid is done by using a

  • sparger
  • kneader
  • masticator
  • none of these
Q.36

Work index is defined as the

  • gross energy (kWh/ton of feed) needed to reduce very large feed to such a size that 80% of the product passes through a 100 micron screen.
  • energy needed to crush one tonne of feed to 200 microns.
  • energy (kWh/ton of feed) needed to crush small feed to such a size that 80% of the product passes a 200 mesh screen.
  • energy needed to crush one ton of feed to 100 microns.
Q.37

For spheres, the specific surface shape factor is given by

  • AD/V
  • D/V
  • A/V
  • AD/V
Q.38

__________ mill is not used for grinding wheat into flour and for milling of cereals & other vegetable products.

  • Buhrstone
  • Roller
  • Attrition
  • Pebble
Q.39

Kick's law relates to

  • energy consumption
  • final particle size
  • feed size
  • none of these
Q.40

To get ultrafine particles, the equipment used is a

  • ball mill
  • rod mill
  • hammer crusher
  • fluid energy mill
Q.41

For a turbine agitated and baffled tank, operating at low Reynold's number (based on impeller diameter), the power number (Np) varies with NRe as

  • NpNRe
  • NpNRe
  • Np → constant
  • Np ∝ 1/NRe
Q.42

Which of the following is a fine crusher?

  • Blake jaw crusher
  • Gyratory crusher
  • Toothed roll crusher
  • Dodge jaw crusher
Q.43

__________ is a cohesive solid.

  • Wheat
  • Sand
  • Wet clay
  • none of these
Q.44

A cottrel precipitator makes use of the __________ for dusty air cleaning.

  • electric spark
  • corrona discharge
  • alternating current
  • none of these.
Q.45

The most suitable equipment for the transportation ofmesh size particles is a

  • bucket elevator
  • pneumatic conveyor
  • screw conveyor
  • belt conveyor
Q.46

Which of the following is not used as filter aid?

  • Asbestos
  • Diatomaceous earth
  • Purified wood cellulose
  • Rice husk
Q.47

Reciprocal of sphericity is termed as the

  • specific surface ratio
  • shape factor
  • sauter diameter
  • surface area per unit mass
Q.48

Which is a secondary crusher for a hard & tough stone ?

  • Jaw crusher
  • Cone crusher
  • Impact crusher
  • Toothed roll crusher
Q.49

Sphericity of pulverised coal is

  • 1
  • <1
  • >1
Q.50

What is the usual value of angle of nip for crushing of ordinary rock in smooth steel crushing rolls ?

  • 16°
  • 32°
  • 40°
  • 46°
0 h : 0 m : 1 s