Q.1
Two particles are called to be equal settling, if they are having the same.
Q.2
Which of the following must be stored in silos and not in open yard?
Q.3
Raw materials are charged in the iron blast furnace using
Q.4
If a force greater than that of gravity is used to separate solids & fluids of different densities, the process is termed as the
Q.5
The capacity of a classifier in 'tons of solid/hr' is given by (where, A = cross-sectional area, m² V = rising velocity of fluid, m/sec.S = percentage of solids in the suspension by volume.ρ = density of solids, kg/m³)
Q.6
The value of 'angle of nip' is generally about
Q.7
A. __________ mill is a revolving mill divided into two or more sections by perforated partitions in which preliminary grinding takes place at one end and the finishing grinding at the discharge end.
Q.8
Vertical transportation of materials can be done by a/an
Q.9
Sphericity is the ratio of the surface area of a spherical particle having the same volume as the particle to the surface area of the particle. Which of the following has the maximum value of sphericity?
Q.10
What is the selectivity index, if the grade of tailings & concentrate is the same?
Q.11
Sphericity of raschig ring (whose length and diameter are equal) is
Q.12
Fluid energy mill comes in the category of
Q.13
__________ mill is not a revolving mill.
Q.14
During size reduction by a jaw crusher, the energy consumed decreases with the
Q.15
Which of the following is not a revolving/tumbling mill used for size reduction?
Q.16
For spheres, the surface shape factor is given by (where, A = area, V = volume, and D = diameter)
Q.17
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
Q.18
The specific cake resistance for incompressible sludges is (where ΔP = pressure drop over cake)
Q.19
Height of liquid in agitation tank is normally maintained equal to the tank diameter. However, if the tank is too tall and a large liquid hold up is desired, then two or more impellers mounted on the same shaft may be used. The clearance between the tank bottom and the bottom most impeller should be about (where, D = impeller diameter)
Q.20
Height of liquid in agitation tank is normally maintained equal to the tank diameter. However, if the tank is too tall and a large liquid hold up is desired, then two or more impellers mounted on the same shaft may be used. The clearance between the tank bottom and the bottom most impeller should be about (where, D = impeller diameter)
Q.21
Filter medium resistance is important during the __________ of filtration.
Q.22
In closed circuit grinding as compared to open circuit grinding, the
Q.23
In washing type plate and frame filter press, the ratio of washing rate to the final filtrate rate is
Q.24
Vibrating screens are used for handling large tonnages of materials. The vibrating motion is imparted to the screening surface by means of
Q.25
Power consumption during turbulent flow in agitation tank is proportional to the __________ of the liquid.
Q.26
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'?
Q.27
For laminar flow of filtrate through the cake deposited on septum, which of the following will be valid?
Q.28
Specific surface area is the surface area of a unit __________ of materials.
Q.29
Colloidal mills are used for __________ grinding.
Q.30
Which of the following oxides is not present in hematite iron ore?
Q.31
Which of the following grinding mills has the horizontally arranged rods as the grinding elements thereby delivering more uniform granular products with minimum fines?
Q.32
Filtration rate does not depend upon the
Q.33
The ratio of the actual mesh dimension of Taylor series to that of the next smaller screen is
Q.34
Equivalent diameter of a particle is the diameter of the sphere having the same
Q.35
Gizzlies are used for separating __________ solids.
Q.36
For grinding of cereals, grains, spices, pigments, saw dust, cork etc., the most extensively used size reduction equipment is a
Q.37
What is the usual value of angle of nip for crushing of ordinary rock in smooth steel crushing rolls?
Q.38
Sauter mean diameter is the same as the __________ mean diameter.
Q.39
Pine oil and cresylic acid are used as __________ in the froth floatation process.
Q.40
Cyclones are used primarily for separating
Q.41
__________ centrifuge is normally used in sugar mills.
Q.42
Grinding characteristic of a material is given by its
Q.43
Which of the following is the most suitable for cleaning of fine coal dust (<0.5 mm)?
Q.44
For coarse reduction of hard solids, use
Q.45
200 mesh screen means 200 openings per
Q.46
Sedimentation on commercial scale occurs in
Q.47
The value of work index does not change materially from one equipment to another. If the value of work index determined for close circuit grinding is Wi, then the same for open circuit grinding will be
Q.48
Shell and leaf filter as compared to plate and frame filter
Q.49
Dust collection efficiency of electrostatic precipitator can be as high as 99.9%. Maximum temperature and pressure of dust laden gas that can be cleaned in an electrostatic precipitator is respectively.
Q.50
The inlet pressure in a constant rate filtration
0 h : 0 m : 1 s