Sphericity of pulverised coal is__________________?
Sphericity of pulverised coal is__________________?
A. 1
B. < 1
C. > 1
D. ∞
Mechanical Operations
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The reduction ratio for grinders is defined as (where, Df and Dp are average diameters of feed and product respectively) ?
The reduction ratio for grinders is defined as (where, Df and Dp are average diameters of feed and product respectively) ?A. Df/Dp
B. Dp/Df
C. Df – Dp
D. None of these -
Maximum size reduction in a ball mill is done by the, ______________ action?
Maximum size reduction in a ball mill is done by the, ______________ action?A. Attrition
B. Compression
C. Impact
D. Cutting -
Which of the following is a fine crusher ?
Which of the following is a fine crusher ?A. Blake jaw crusher
B. Gyratory crusher
C. Toothed roll crusher
D. Dodge jaw crusher -
_______________ mixer is used for devulcanisation of rubber scrap & making water dispersion & rubber solution?
_______________ mixer is used for devulcanisation of rubber scrap & making water dispersion & rubber solution?A. Tumbler
B. Banbury
C. Muller
D. Ribbon blender -
For spheres, the surface shape factor is given by (where, A = area, V = volume, and D = diameter) ?
For spheres, the surface shape factor is given by (where, A = area, V = volume, and D = diameter) ?A. π = (A/D2)
B. π/6 = (V/D3)
C. AD/V
D. None of these -
Gravity stamp mill is meant for the ___________________ crushing?
Gravity stamp mill is meant for the ___________________ crushing?A. Primary
B. Intermediate
C. Fine
D. Ultrafine -
Reciprocating screens are normally inclined at an angle of 5° with the horizontal and employ gyratory motion at feed end & reciprocating motion at the discharge end. They are not suitable for the screening of the ___________________?
Reciprocating screens are normally inclined at an angle of 5° with the horizontal and employ gyratory motion at feed end & reciprocating motion at the discharge end. They are not suitable for the screening of the ___________________?A. Light metal powder down upto 4 mesh size
B. Dry chemicals
C. Heavy tonnages of rocks or gravel
D. Powdered food & granular materials -
A fluid energy mill is used for __________________?
A fluid energy mill is used for __________________?A. Cutting
B. Grinding
C. Ultra-grinding
D. Crushing -
In a size reduction crushing operation, the feed size is 10 to 50 mm, while the product size is 2 to 10 mm. This is a case of _______________ crushing?
In a size reduction crushing operation, the feed size is 10 to 50 mm, while the product size is 2 to 10 mm. This is a case of _______________ crushing?A. Primary
B. Secondary
C. Fine
D. Ultrafine