The mechanism of size reduction by a hammer mill is by impact and attrition between the (A) Grinding element & the housing (B) Feed particles (C) Both (A) and (B) (D) Neither (A) nor (B)

The mechanism of size reduction by a hammer mill is by impact and
attrition between the
(A) Grinding element & the housing
(B) Feed particles
(C) Both (A) and (B)
(D) Neither (A) nor (B)
by

1 Answer

Answer :

(C) Both (A) and (B)
by

Related questions

The grinding in a hammer crusher takes place due to the (A) Attrition (B) Impact (C) Both (A) & (B) (D) Neither (A) nor (B

Description : The grinding in a hammer crusher takes place due to the (A) Attrition (B) Impact (C) Both (A) & (B) (D) Neither (A) nor (B

Last Answer : (C) Both (A) & (B)

Toothed roll crushers achieve size reduction by (A) Tearing (shear) and compression (B) Impact and attrition (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Toothed roll crushers achieve size reduction by (A) Tearing (shear) and compression (B) Impact and attrition (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Size reduction of moulding powders, waxes, resins & gums are done in a __________ mill. (A) Cage (B) Hammer (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Size reduction of moulding powders, waxes, resins & gums are done in a __________ mill. (A) Cage (B) Hammer (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Which of the following size reduction equipments employs mainly attrition for ultrafine grinding? (A) Jet mills (B) Fluid energy mill (C) Micronizer (D) All (A), (B) and (C)

Description : Which of the following size reduction equipments employs mainly attrition for ultrafine grinding? (A) Jet mills (B) Fluid energy mill (C) Micronizer (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

For grinding of cereals, grains, spices, pigments, saw dust, cork etc., the most extensively used size reduction equipment is a(A) Buhrstone mill(B) Ball mill(C) Crushing rolls(D) Hammer mill

Description : For grinding of cereals, grains, spices, pigments, saw dust, cork etc., the most extensively used size reduction equipment is a (A) Buhrstone mill (B) Ball mill (C) Crushing rolls (D) Hammer mill

Last Answer : (A) Buhrstone mill

Maximum size reduction in a fluid energy mill is achieved by (A) Compression (B) Interparticle attrition (C) Cutting (D) Impact

Description : Maximum size reduction in a fluid energy mill is achieved by (A) Compression (B) Interparticle attrition (C) Cutting (D) Impact

Last Answer : (B) Interparticle attrition

Maximum size reduction in a ball mill is done by the, __________ action. (A) Attrition (B) Compression (C) Impact (D) Cutting

Description : Maximum size reduction in a ball mill is done by the, __________ action. (A) Attrition (B) Compression (C) Impact (D) Cutting

Last Answer : (C) Impact

General mechanism of size reduction in intermediate and fine grinder is by (A) Cutting action (B) Compression (C) Compression and tearing (D) Impact and attrition

Description : General mechanism of size reduction in intermediate and fine grinder is by (A) Cutting action (B) Compression (C) Compression and tearing (D) Impact and attrition

Last Answer : (D) Impact and attrition

Close circuit grinding by a ball mill with air sweeping employs a (A) Classifier (B) Cyclone separator between mill & classifier (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Close circuit grinding by a ball mill with air sweeping employs a (A) Classifier (B) Cyclone separator between mill & classifier (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

__________ mill is not used for grinding wheat into flour and for milling of cereals & other vegetable products. (A) Buhrstone (B) Roller (C) Attrition (D) Pebble

Description : __________ mill is not used for grinding wheat into flour and for milling of cereals & other vegetable products. (A) Buhrstone (B) Roller (C) Attrition (D) Pebble

Last Answer : (D) Pebble

Ball mill is used for (A) Crushing (B) Coarse grinding (C) Fine grinding (D) Attrition

Description : Ball mill is used for (A) Crushing (B) Coarse grinding (C) Fine grinding (D) Attrition

Last Answer : (C) Fine grinding

In case of a hammer crusher, the final product size depends on the (A) Feed rate (B) Rotor speed(C) Clearance between hammer & grinding plates(D) All (A), (B) and (C

Description : In case of a hammer crusher, the final product size depends on the (A) Feed rate (B) Rotor speed (C) Clearance between hammer & grinding plates (D) All (A), (B) and (C

Last Answer : (D) All (A), (B) and (C

In case of a hammer crusher, (A) Crushing takes place by impact breaking (B) Maximum acceptable feed size is 30 cms (C) Reduction ratio can be varied by adjusting the distance from cage to hammers (D) All (A), (B) and (C)

Description : In case of a hammer crusher, (A) Crushing takes place by impact breaking (B) Maximum acceptable feed size is 30 cms (C) Reduction ratio can be varied by adjusting the distance from cage to hammers (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Size reduction mechanism used in Jaw crushers is (A) Attrition (B) Compression

Description : Size reduction mechanism used in Jaw crushers is (A) Attrition (B) Compression

Last Answer : (B) Compression

The main size reduction operation in ultrafine grinders is (A) Cutting (B) Attrition (C) Compression (D) Impact

Description : The main size reduction operation in ultrafine grinders is (A) Cutting (B) Attrition (C) Compression (D) Impact

Last Answer : (B) Attrition

Colloid mills achieve size reduction mainly by (A) Impact (B) Attrition (C) Cutting (D) Compression

Description : Colloid mills achieve size reduction mainly by (A) Impact (B) Attrition (C) Cutting (D) Compression

Last Answer : (B) Attrition

Pick out the wrong statement. (A) More commonly used jaw crusher between Dodge jaw crusher and Blake jaw crusher is the later one(B) There are only four methods namely compression, impact, attrition andcutting, which the size reduction equipments employ(C) Cutting machines mainly employ 'attrition' for size reduction of solids(D) Operating principles of Dodge and Blake jaw crushers are combined inthe working of universal jaw crushers

Description : Pick out the wrong statement. (A) More commonly used jaw crusher between Dodge jaw crusher and Blake jaw crusher is the later one (B) There are only four methods namely compression, impact ... Operating principles of Dodge and Blake jaw crushers are combined in the working of universal jaw crushers

Last Answer : (C) Cutting machines mainly employ 'attrition' for size reduction of solids

__________ balls capable of grinding the feed in a ball mill gives the maximum efficiency. (A) Cast iron (B) Minimum size (C) Maximum size (D) Elliptical

Description : __________ balls capable of grinding the feed in a ball mill gives the maximum efficiency. (A) Cast iron (B) Minimum size (C) Maximum size (D) Elliptical

Last Answer : (B) Minimum size

Explain the working, advantages and disadvantages of any one mill based on the principle of combined impact and attrition?

Description : Explain the working, advantages and disadvantages of any one mill based on the principle of combined impact and attrition?

Last Answer : which of the following mill works on the principle of combined impact and attrition

Use of grinding aids results in the (A) Enhanced production rate (B) Finer products (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Use of grinding aids results in the (A) Enhanced production rate (B) Finer products (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (D) Neither (A) nor (B)

Work index is the gross energy (kWh/tonne of feed) necessary to reduce a very large feed to such a size that 80% of product particles will pass through a 0.1 mm screen. The value of work index determined for wet grinding should be multiplied with __________ to get the same for dry grinding. (A) 1.0 (B) 0.5 (C) 1.34 (D) 4.34

Description : Work index is the gross energy (kWh/tonne of feed) necessary to reduce a very large feed to such a size that 80% of product particles will pass through a 0.1 mm screen. The value of work index determined for wet grinding should ... to get the same for dry grinding. (A) 1.0 (B) 0.5 (C) 1.34 (D) 4.34

Last Answer : (C) 1.34

For coarse reduction of hard solids, use (A) Impact (B) Attrition (C) Compression (D) Cutting

Description : For coarse reduction of hard solids, use (A) Impact (B) Attrition (C) Compression (D) Cutting

Last Answer : (C) Compression

In a grinding operation, the limiting particle size is the size of the __________ particle in the sample. (A) Smallest (B) Largest (C) Either (A) or (B) (D) Neither (A) nor (B)

Description : In a grinding operation, the limiting particle size is the size of the __________ particle in the sample. (A) Smallest (B) Largest (C) Either (A) or (B) (D) Neither (A) nor (B)

Last Answer : (D) Neither (A) nor (B)

Actual operating speed of a ball mill may vary from 65 to 80% of the critical speed. Which of the following duties would require the ball mill to be operated at maximum percentage of critical speed? (A) Wet grinding in low viscous suspension (B) Wet grinding in high viscous suspension (C) Dry grinding of large particles (upto 1.25 cms) (D) Dry grinding of large particles in un-baffed mills

Description : Actual operating speed of a ball mill may vary from 65 to 80% of the critical speed. Which of the following duties would require the ball mill to be operated at maximum percentage of critical speed? (A) ... of large particles (upto 1.25 cms) (D) Dry grinding of large particles in un-baffed mills

Last Answer : (D) Dry grinding of large particles in un-baffed mills

To get ultrafine particles, the equipment used is a (A) Ball mill (B) Rod mill (C) Hammer crusher (D) Fluid energy mill

Description : To get ultrafine particles, the equipment used is a (A) Ball mill (B) Rod mill (C) Hammer crusher (D) Fluid energy mill

Last Answer : (D) Fluid energy mill

Wheat is ground into flour in a (A) Hammer crusher (B) Roller crusher (C) Impact mill (D) Fluid energy mill

Description : Wheat is ground into flour in a (A) Hammer crusher (B) Roller crusher (C) Impact mill (D) Fluid energy mill

Last Answer : (B) Roller crusher

Out of the following size reduction equipments, the maximum feed size can be accepted by the (A) Tube mill (B) Ball mill (C) Jaw crusher (D) Jet pulveriser

Description : Out of the following size reduction equipments, the maximum feed size can be accepted by the (A) Tube mill (B) Ball mill (C) Jaw crusher (D) Jet pulveriser

Last Answer : (C) Jaw crusher

The uniformity of a gas fluidised bed depends upon the __________ of the solid particles. (A) Size (B) Surface properties (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : The uniformity of a gas fluidised bed depends upon the __________ of the solid particles. (A) Size (B) Surface properties (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) and (B)

In case of grinding in a ball mill (A) Wet grinding achieves a finer product size than dry grinding (B) Its capacity decreases with increasing fineness of the products (C) Grinding cost and power requirement increases with increasing fineness of the products (D) All (A), (B) and (C)

Description : In case of grinding in a ball mill (A) Wet grinding achieves a finer product size than dry grinding (B) Its capacity decreases with increasing fineness of the products (C) Grinding cost and power requirement increases with increasing fineness of the products (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

The main differentiation factor between tube mill and ball mill is the (A) Length to diameter ratio (B) Size of the grinding media (C) Final product size (D) Operating speed

Description : The main differentiation factor between tube mill and ball mill is the (A) Length to diameter ratio (B) Size of the grinding media (C) Final product size (D) Operating speed

Last Answer : (A) Length to diameter ratio

Additives used for promoting the flocculation of particles is a/an (A) Electrolyte (B) Surface active agent (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Additives used for promoting the flocculation of particles is a/an (A) Electrolyte (B) Surface active agent (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Horsepower required for a roll crusher is directly proportional to its (A) Reduction ratio (B) Capacity(C) Both (A) & (B)(D) Neither (A) nor (B)

Description : Horsepower required for a roll crusher is directly proportional to its (A) Reduction ratio (B) Capacity (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Coal is finally pulverised to 200 mesh size for burning in boilers by a (A) Hammer crusher(B) Ball mill(C) Roll crusher(D) Gyratory crusher

Description : Coal is finally pulverised to 200 mesh size for burning in boilers by a (A) Hammer crusher (B) Ball mill (C) Roll crusher (D) Gyratory crusher

Last Answer : (B) Ball mill

Cement clinker is reduced to fine size by a (A) Roll crusher (B) Ball mill (C) Tube mill (D) Hammer mill

Description : Cement clinker is reduced to fine size by a (A) Roll crusher (B) Ball mill (C) Tube mill (D) Hammer mill

Last Answer : (C) Tube mill

Pick out the wrong statement. (A) Gape is the greatest distance between the crushing surfaces or the jaws (B) The angle of nip (2α) is the angle between roll faces at the level where they will just take hold of a particle and draw it in the crushing zone (C) Crushing efficiency is the ratio of the energy absorbed by the solid to the surfaces energy created by crushing (D) Reduction ratio is the ratio of the maximum size of the particles in the feed to that in the product

Description : Pick out the wrong statement. (A) Gape is the greatest distance between the crushing surfaces or the jaws (B) The angle of nip (2α) is the angle between roll faces at the level where they will ... Reduction ratio is the ratio of the maximum size of the particles in the feed to that in the product

Last Answer : (C) Crushing efficiency is the ratio of the energy absorbed by the solid to the surfaces energy created by crushing

The constants (Kb, Kr and Kk) used in the laws of crushing (i.e., Bond's law, Rittinger's law and Kick's law) depend upon the (A) Feed material (B) Type of crushing machine (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The constants (Kb, Kr and Kk) used in the laws of crushing (i.e., Bond's law, Rittinger's law and Kick's law) depend upon the (A) Feed material (B) Type of crushing machine (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Filtration capacity of a rotary drum vacuum filter depends upon the (A) Cake thickness (B) Characteristics of the feed slurry (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Filtration capacity of a rotary drum vacuum filter depends upon the (A) Cake thickness (B) Characteristics of the feed slurry (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Pebble mills are tumbling mills widely used for grinding in the manufacture of paints & pigments and cosmetic industries, where iron contamination in the product is highly objectionable. Pebbles used in pebble mill are made of (A) Bronze (B) Stainless steel (C) Flint or porcelain (D) Concrete

Description : Pebble mills are tumbling mills widely used for grinding in the manufacture of paints & pigments and cosmetic industries, where iron contamination in the product is highly objectionable. Pebbles used in pebble mill are made of (A) Bronze (B) Stainless steel (C) Flint or porcelain (D) Concrete

Last Answer : (C) Flint or porcelain

Rod mills employed for grinding (A) Employ a steel shell having L/D ratio of 1.5 to 3.0 (B) Is useful for handling sticky materials (C) Employ steel rods of 2-12 cms diameter extending over full length of the mill (D) All 'a', 'b' & 'c'

Description : Rod mills employed for grinding (A) Employ a steel shell having L/D ratio of 1.5 to 3.0 (B) Is useful for handling sticky materials (C) Employ steel rods of 2-12 cms diameter extending over full length of the mill (D) All 'a', 'b' & 'c'

Last Answer : (D) All 'a', 'b' & 'c'

In case of a revolving mill, wet grinding compared to dry grinding (A) Requires more energy (B) Has less capacity (C) Complicates handling & classification of the product (D) None of these

Description : In case of a revolving mill, wet grinding compared to dry grinding (A) Requires more energy (B) Has less capacity (C) Complicates handling & classification of the product (D) None of these

Last Answer : (D) None of these

A patient has improperly formed DEJ, reduction in size of pulp chamber, chipping and attrition of enamel that would MOSTLY be: A. Fluorosis B. Amelogenesis imperfecta C. Dentinogenesis imperfecta

Description : A patient has improperly formed DEJ, reduction in size of pulp chamber, chipping and attrition of enamel that would MOSTLY be: A. Fluorosis B. Amelogenesis imperfecta C. Dentinogenesis imperfecta

Last Answer : C. Dentinogenesis imperfecta

Crushing of mineral particles is accomplished in a 'cage mill', when one or more alloy steel bars are revolved in opposite directions. It is a type of __________ mill. (A) Impact (B) Roll (C) Vibratory (D) None of these

Description : Crushing of mineral particles is accomplished in a 'cage mill', when one or more alloy steel bars are revolved in opposite directions. It is a type of __________ mill. (A) Impact (B) Roll (C) Vibratory (D) None of these

Last Answer : (A) Impact

A pebble mill (A) Is a ball mill (B) Employs flints or ceramic pebbles as the grinding medium (C) Is a tube mill lined with ceramic or other non-metallic liner (D) Both (B) and (C)

Description : A pebble mill (A) Is a ball mill (B) Employs flints or ceramic pebbles as the grinding medium (C) Is a tube mill lined with ceramic or other non-metallic liner (D) Both (B) and (C)

Last Answer : (D) Both (B) and (C)

A bolometer is (A) Used for the measurement of thermal radiation (B) An element which senses optical input and delivers thermal output (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : A bolometer is (A) Used for the measurement of thermal radiation (B) An element which senses optical input and delivers thermal output (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

In screen analysis, the notation +5 mm/-10 mm means particles passing through (A) 10 mm screen and retained on 5 mm screen (B) 5 mm screen and retained on 10 mm screen (C) Both 5 mm and 10 mm screens (D) Neither 5 mm nor 10 mm screen

Description : In screen analysis, the notation +5 mm/-10 mm means particles passing through (A) 10 mm screen and retained on 5 mm screen (B) 5 mm screen and retained on 10 mm screen (C) Both 5 mm and 10 mm screens (D) Neither 5 mm nor 10 mm screen

Last Answer : (A) 10 mm screen and retained on 5 mm screen

In a roll crusher, the specific power consumption and the production rate is affected by the (A) Reduction ratio (B) Differential roll speed (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : In a roll crusher, the specific power consumption and the production rate is affected by the (A) Reduction ratio (B) Differential roll speed (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) and (B)

Size reduction of asbestos and mica is done by (A) Hammer mills (B) Rod mills (C) Gyratory crushers (D) Crushing rolls

Description : Size reduction of asbestos and mica is done by (A) Hammer mills (B) Rod mills (C) Gyratory crushers (D) Crushing rolls

Last Answer : (A) Hammer mills

Pick out the wrong statement pertaining to the roll crushers. (A) Maximum feed size determines the required roll diameter (B) For hard material's crushing, the reduction ratio should not exceed 4 (C) Both the rolls run necessarily at the same speed (D) Reduction ratio and differential roll speed affect production rate & energy consumed per unit of surface produced

Description : Pick out the wrong statement pertaining to the roll crushers. (A) Maximum feed size determines the required roll diameter (B) For hard material's crushing, the reduction ratio should not ... ratio and differential roll speed affect production rate & energy consumed per unit of surface produced

Last Answer : (C) Both the rolls run necessarily at the same speed

Pick out the wrong statement: (A) Magnetic separation method can be employed to treat both dry & wet ores (B) Reduction ratio in crushing operation is defined as the ratio of minimum feed size to the maximum product size (C) Gyratory crusher is used for coarse crushing (D) Screens are of stationary, moving and vibratory types

Description : Pick out the wrong statement: (A) Magnetic separation method can be employed to treat both dry & wet ores (B) Reduction ratio in crushing operation is defined as the ratio of minimum feed ... ) Gyratory crusher is used for coarse crushing (D) Screens are of stationary, moving and vibratory types

Last Answer : (B) Reduction ratio in crushing operation is defined as the ratio of minimum feed size to the maximum product size

Alloy powder manufactured by the following process have spherical shapes. (A) Electrochemical deposition (B) Gaseous reduction (C) Atomisation (D) Mechanical attrition

Description : Alloy powder manufactured by the following process have spherical shapes. (A) Electrochemical deposition (B) Gaseous reduction (C) Atomisation (D) Mechanical attrition

Last Answer : (C) Atomisation