In a size reduction crushing operation, feed size is 100 to 300 mm. while the product size is 10 to 50 mm. This is a case of the __________ crushing. (A) Primary (B) Secondary (C) Fine (D) Ultrafine

In a size reduction crushing operation, feed size is 100 to 300 mm. while
the product size is 10 to 50 mm. This is a case of the __________ crushing.
(A) Primary
(B) Secondary
(C) Fine
(D) Ultrafine
by

1 Answer

Answer :

(B) Secondary
by

Related questions

In a size reduction crushing operation, feed size is 300 to 1500 mm while the product size is 100 to 300 mm. This is a case of the __________ crushing. (A) Secondary (B) Fine (C) Primary (D) Ultrafine

Description : In a size reduction crushing operation, feed size is 300 to 1500 mm while the product size is 100 to 300 mm. This is a case of the __________ crushing. (A) Secondary (B) Fine (C) Primary (D) Ultrafine

Last Answer : (C) Primary

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

Description : 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

Last Answer : (C) Fine

Gravity stamp mill is meant for the __________ crushing. (A) Primary (B) Intermediate (C) Fine (D) Ultrafine

Description : Gravity stamp mill is meant for the __________ crushing. (A) Primary (B) Intermediate (C) Fine (D) Ultrafine

Last Answer : (C) Fine

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

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)

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

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

Energy consumption in a crusher decreases with increase in the (A) Size of the product (at constant feed size) (B) Capacity of the crushing machine (C) Size of feed (at constant reduction ratio) (D) All (A), (B) & (C)

Description : Energy consumption in a crusher decreases with increase in the (A) Size of the product (at constant feed size) (B) Capacity of the crushing machine (C) Size of feed (at constant reduction ratio) (D) All (A), (B) & (C)

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

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

. In case of a hammer crusher, the (A) Feed may be highly abrasive (Moh's scale >5) (B) Minimum product size is 3 mm (C) Maximum feed size may be 50 mm (D) Rotor shaft carrying hammers can be vertical or horizontal

Description : . In case of a hammer crusher, the (A) Feed may be highly abrasive (Moh's scale >5) (B) Minimum product size is 3 mm (C) Maximum feed size may be 50 mm (D) Rotor shaft carrying hammers can be vertical or horizontal

Last Answer : (D) Rotor shaft carrying hammers can be vertical or horizontal

Generally the strength of concrete is represented by the crushing stress of concrete cube of size [ A ] 50 mm [ B ] 100 mm [ C ] 150 mm [ D ] 250 mm

Description : Generally the strength of concrete is represented by the crushing stress of concrete cube of size [ A ] 50 mm [ B ] 100 mm [ C ] 150 mm [ D ] 250 mm

Last Answer : [ C ] 150 mm

Pick out the wrong statement. (A) Recycled coarse material to the grinder by a classifier is termed as circulating load (B) Wear and tear in wet crushing is more than that in dry crushing of materials (C) Size enlargement (opposite of size reduction) is not a mechanical operation (D) 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

Description : Pick out the wrong statement. (A) Recycled coarse material to the grinder by a classifier is termed as circulating load (B) Wear and tear in wet crushing is more than that in dry crushing of ... a pipeline which permits the solids to settle down due to reduction in velocity of the dust laden gas

Last Answer : (C) Size enlargement (opposite of size reduction) is not a mechanical operation

Colloidal mills are used for __________ grinding. (A) Coarse (B) Intermediate (C) Fine (D) Ultrafine

Description : Colloidal mills are used for __________ grinding. (A) Coarse (B) Intermediate (C) Fine (D) Ultrafine

Last Answer : (D) Ultrafine

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 achieving rapid drying rate in a spray dryer, the diameter of the particles in the feed should be in the range of __________ microns (1 mm = 1000 microns). (A) 1-5 (B) 10-60 (C) 200-300

Description : For achieving rapid drying rate in a spray dryer, the diameter of the particles in the feed should be in the range of __________ microns (1 mm = 1000 microns). (A) 1-5 (B) 10-60 (C) 200-300

Last Answer : (B) 10-60

According to Bond crushing law, the work required to form particle of size 'D' from very large feed is (where (S/V)p and (S/V) f are surface to volume ratio of the product and feed respectively). (A) (S/V)p (B) √(S/V)p (C) (S/V) 2 p (D) (S/V) f

Description : According to Bond crushing law, the work required to form particle of size 'D' from very large feed is (where (S/V)p and (S/V) f are surface to volume ratio of the product and feed respectively). (A) (S/V)p (B) √(S/V)p (C) (S/V) 2 p (D) (S/V) f

Last Answer : (B) √(S/V)

Rittinger's crushing law states that (A) Work required to form a particle of any size is proportional to the square of the surface to volume ratio of the product (B) Work required to form a particle of a particular size is proportional to the square root of the surface to volume ratio of the product (C) Work required in crushing is proportional to the new surface created (D) For a given machine and feed, crushing efficiency is dependent on the size of the feed & product

Description : Rittinger's crushing law states that (A) Work required to form a particle of any size is proportional to the square of the surface to volume ratio of the product (B) Work required to form a ... ) For a given machine and feed, crushing efficiency is dependent on the size of the feed & product

Last Answer : (C) Work required in crushing is proportional to the new surface created

Bond crushing law (A) Calls for relatively less energy for the smaller product particles, than does the Rittinger law (B) Is less realistic in estimating the power requirements of commercial crushers (C) States that the work required to form particle of any size from very large feed is proportional to the square root of the volume to surface ratio of the product (D) States that the work required for the crushing is proportional to the new surface created

Description : Bond crushing law (A) Calls for relatively less energy for the smaller product particles, than does the Rittinger law (B) Is less realistic in estimating the power requirements of commercial crushers ( ... (D) States that the work required for the crushing is proportional to the new surface created

Last Answer : (A) Calls for relatively less energy for the smaller product particles, than does the Rittinger law

Angle of nip of the crushing rolls does not depend upon the (A) Diameter of the rolls (B) Speed of the rolls (C) Product size (D) Feed size

Description : Angle of nip of the crushing rolls does not depend upon the (A) Diameter of the rolls (B) Speed of the rolls (C) Product size (D) Feed size

Last Answer : (B) Speed of the rolls

Size reduction of the __________ can be suitably done by ball mills, crushing rolls and rod mills. (A) Metalliferous ores (B) Non-metallic ores (C) Basic slags (D) Asbestos & mica

Description : Size reduction of the __________ can be suitably done by ball mills, crushing rolls and rod mills. (A) Metalliferous ores (B) Non-metallic ores (C) Basic slags (D) Asbestos & mica

Last Answer : (A) Metalliferous ores

General crushing equation is given by d(P/m) = -K (dD̅S /D̅ n S ). Bond's crushing law is obtained by solving this equation for n = __________ and feed of infinite size. (A) 1 (B) 1.5 (C) 2 (D) 2.5

Description : General crushing equation is given by d(P/m) = -K (dD̅S /D̅ n S ). Bond's crushing law is obtained by solving this equation for n = __________ and feed of infinite size. (A) 1 (B) 1.5 (C) 2 (D) 2.5

Last Answer : (B) 1.5

Pick out the correct statement. (A) Plastic chips are called non-cohesive solids (B) Kick's crushing law is, P/m = K . ln (D̅sa /Ds̅b ) (C) Communition is a generic term for size enlargement operation (D) Energy required in kwh per ton of product, such that 80% of it passes through a 200 mesh screen, is called 'Work index'

Description : Pick out the correct statement. (A) Plastic chips are called non-cohesive solids (B) Kick's crushing law is, P/m = K . ln (D̅sa /Ds̅b ) (C) Communition is a generic term for size enlargement ... per ton of product, such that 80% of it passes through a 200 mesh screen, is called 'Work index'

Last Answer : (B) Kick's crushing law is, P/m = K . ln (D̅sa /Ds̅b )

Flat rate parcel rates Flat Rate Parcel Boxes size Dimension of boxes (in mm) Weight (in Kg.) Tariff (in Rs.) Small - S 250*50*300 0 to 1 125 Medium - M 250*100*300 Above 1 to 2.5 200 Large - L 300*250*200 Above 2.5 to 5 400

Description : Flat rate parcel rates Flat Rate Parcel Boxes size Dimension of boxes (in mm) Weight (in Kg.) Tariff (in Rs.) Small - S 250*50*300 0 to 1 125 Medium - M 250*100*300 Above 1 to 2.5 200 Large - L 300*250*200 Above 2.5 to 5 400

Last Answer : Large - L 300*250*200 Above 2.5 to 5 400

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

Brownian movement is prominent in the particle size range of __________ microns in case of settling of a particle in a fluid. (A) 2 to 3 (B) 0.01 to 0.10 (C) 200 to 300 (D) 100 to 1000

Description : Brownian movement is prominent in the particle size range of __________ microns in case of settling of a particle in a fluid. (A) 2 to 3 (B) 0.01 to 0.10 (C) 200 to 300 (D) 100 to 1000

Last Answer : A) 2 to 3

Foaming and priming in boiler operation can be reduced by reduction in __________ in feed water. (A) Turbidity (B) Color (Hazen) (C) Total solids (D) All (A), (B) & (C)

Description : Foaming and priming in boiler operation can be reduced by reduction in __________ in feed water. (A) Turbidity (B) Color (Hazen) (C) Total solids (D) All (A), (B) & (C)

Last Answer : (D) All (A), (B) & (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

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

For crushing of solids, the Rittinger's law states that the work required for crushing is proportional to(A) The new surface created(B) The size reduction ratio(C) The change in volume due to crushing(D) None of these

Description : For crushing of solids, the Rittinger's law states that the work required for crushing is proportional to (A) The new surface created (B) The size reduction ratio (C) The change in volume due to crushing (D) None of these

Last Answer : (A) The new surface created

. Which of the following equations is Rittinger's crushing law? (Where P = power required by the machine, m = feed rate, k = a constant, Ds̅a & D̅sb = volume surface mean diameter of feed & product respectively.) (A) P/m = K/ √Dp (B) P/m = K . ln D̅sa /D̅sb (C) P/m = K . (1/ D̅sb - 1/Ds̅a ) (D) None of these

Description : . Which of the following equations is Rittinger's crushing law? (Where P = power required by the machine, m = feed rate, k = a constant, Ds̅a & D̅sb = volume surface mean diameter of feed & product respectively.) (A) P/m = K/ ... K . ln D̅sa /D̅sb (C) P/m = K . (1/ D̅sb - 1/Ds̅a ) (D) None of these

Last Answer : (C) P/m = K . (1/ D̅sb - 1/Ds̅a )

Vibrating screens have capacity in the range of __________ tons/ft 2 .mm mesh size. (A) 0.2 to 0.8 (B) 5 to 25 (C) 50 to 100 (D) 100 to 250

Description : Vibrating screens have capacity in the range of __________ tons/ft 2 .mm mesh size. (A) 0.2 to 0.8 (B) 5 to 25 (C) 50 to 100 (D) 100 to 250

Last Answer : (A) 0.2 to 0.8

In favourable circumstances a 15 cm concrete cube after 28 days, attains a maximum crushing strength (A) 100 kg/cm2 (B) 200 kg/cm2 (C) 300 kg/cm2 (D) 400 kg/cm

Description : In favourable circumstances a 15 cm concrete cube after 28 days, attains a maximum crushing strength (A) 100 kg/cm2 (B) 200 kg/cm2 (C) 300 kg/cm2 (D) 400 kg/cm

Last Answer : Answer: Option D

During size reduction by a jaw crusher, the energy consumed decreases with the (A) Decreasing size of product at constant size of feed (B) Decreasing machine capacity (C) Increasing size of feed at constant reduction ratio (D) None of these

Description : During size reduction by a jaw crusher, the energy consumed decreases with the (A) Decreasing size of product at constant size of feed (B) Decreasing machine capacity (C) Increasing size of feed at constant reduction ratio (D) None of these

Last Answer : (C) Increasing size of feed at constant reduction ratio

A cantilever shaft having 50 mm diameter and length of 300 mm has a disc of mass 100 kg at its free enD. The Young’s modulus for the shaft material is 200 GN/m 2 . Calculate the natural longitudinal frequency in Hz. A. 575B. 625 C. 525 D. 550

Description : A cantilever shaft having 50 mm diameter and length of 300 mm has a disc of mass 100 kg at its free enD. The Young’s modulus for the shaft material is 200 GN/m 2 . Calculate the natural longitudinal frequency in Hz. A. 575B. 625 C. 525 D. 550

Last Answer : A. 575

A cantilever shaft having 50 mm diameter and a length of 300 mm has a disc of mass 100 kg at its free end. The Young’s modulus for the shaft material is 200 GN/m 3 . Determine the static deflection of the shaft in mm. a) 0.147 b) 0.213 c) 0.132 d) 0.112

Description : A cantilever shaft having 50 mm diameter and a length of 300 mm has a disc of mass 100 kg at its free end. The Young’s modulus for the shaft material is 200 GN/m 3 . Determine the static deflection of the shaft in mm. a) 0.147 b) 0.213 c) 0.132 d) 0.112

Last Answer : a) 0.147

A cantilever shaft having 50 mm diameter and a length of 300 mm has a disc of mass 100 kg at its free end. The Young’s modulus for the shaft material is 200 GN/m 2 . Determine the frequency of transverse vibrations of the shaft. a) 31 b) 35 c) 37 d) 41

Description : A cantilever shaft having 50 mm diameter and a length of 300 mm has a disc of mass 100 kg at its free end. The Young’s modulus for the shaft material is 200 GN/m 2 . Determine the frequency of transverse vibrations of the shaft. a) 31 b) 35 c) 37 d) 41

Last Answer : d) 41

A cantilever shaft having 50 mm diameter and length of 300 mm has a disc of mass 100 kg at its free end. The Young’s modulus for the shaft material is 200 GN/m 2 . Calculate the natural longitudinal frequency in Hz. a) 575 b) 625 c) 525 d) 550

Description : A cantilever shaft having 50 mm diameter and length of 300 mm has a disc of mass 100 kg at its free end. The Young’s modulus for the shaft material is 200 GN/m 2 . Calculate the natural longitudinal frequency in Hz. a) 575 b) 625 c) 525 d) 550

Last Answer : a) 575

The reduction ratio for fine grinders is (A) 5-10 (B) 10-20 (C) 20-40 (D) As high as 100

Description : The reduction ratio for fine grinders is (A) 5-10 (B) 10-20 (C) 20-40 (D) As high as 100

Last Answer : (D) As high as 100

Size measurement of ultrafine particles can be best expressed in terms of (A) Centimetre (B) Screen size (C) Micron (D) Surface area per unit mass

Description : Size measurement of ultrafine particles can be best expressed in terms of (A) Centimetre (B) Screen size (C) Micron (D) Surface area per unit mass

Last Answer : (D) Surface area per unit mass

Temperature of the product during ultrafine grinding (A) Increases (B) Decreases (C) Remain constant (D) May increase or decrease; depends on the material being ground

Description : Temperature of the product during ultrafine grinding (A) Increases (B) Decreases (C) Remain constant (D) May increase or decrease; depends on the material being ground

Last Answer : (A) Increases

Use of 'grinding aids' is done in __________ grinding. (A) Dry (B) Wet (C) Ultrafine (D) Intermediate

Description : Use of 'grinding aids' is done in __________ grinding. (A) Dry (B) Wet (C) Ultrafine (D) Intermediate

Last Answer : (A) Dry

For the transportation of ultrafine particles, the equipment used is a __________ conveyor. (A) Belt (B) Pneumatic (C) Screw (D) None of these

Description : For the transportation of ultrafine particles, the equipment used is a __________ conveyor. (A) Belt (B) Pneumatic (C) Screw (D) None of these

Last Answer : (B) Pneumatic

It is desired to concentrate a 20% salt solution (20 kg of salt in 100 kg of solution) to a 30% salt solution in an evaporator. Consider a feed of 300 kg/min at 30°C. The boiling point of the solution is 110°C, the latent heat of vaporisation is 2100 kJ/kg and the specific heat of the solution is 4 kJ/kg.K. The rate at which the heat has to be supplied in (kJ/min) to the evaporator is (A) 3.06 × 10 5 (B) 6.12 × 10 5 (C) 7.24 × 10 5 (D) 9.08 × 10

Description : It is desired to concentrate a 20% salt solution (20 kg of salt in 100 kg of solution) to a 30% salt solution in an evaporator. Consider a feed of 300 kg/min at 30°C. The boiling point of the solution is 110°C, the latent heat of ... 3.06 10 5 (B) 6.12 10 5 (C) 7.24 10 5 (D) 9.08 10

Last Answer : (A) 3.06 × 10

Which of the following crushing laws is most accurately applicable to the fine grinding of materials? (A) Bond's crushing law (B) Kick's law (C) Rittinger's law (D) None of these

Description : Which of the following crushing laws is most accurately applicable to the fine grinding of materials? (A) Bond's crushing law (B) Kick's law (C) Rittinger's law (D) None of these

Last Answer : (C) Rittinger's law

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 ball mill, (A) Coarse feed requires a larger ball (B) Fine feed requires a larger ball (C) Operating speed should be more than the critical speed (D) None of these

Description : In case of a ball mill, (A) Coarse feed requires a larger ball (B) Fine feed requires a larger ball (C) Operating speed should be more than the critical speed (D) None of these

Last Answer : (A) Coarse feed requires a larger ball

The Maximum spacing of Secondary reinforcement in slabs should be [ A ] Less than 450 mm [ B ] Less than 300 mm [ C ] Smaller of three times the effective depth and 450 mm [ D ] Smaller of five times the effective depth and 450 mm

Description : The Maximum spacing of Secondary reinforcement in slabs should be [ A ] Less than 450 mm [ B ] Less than 300 mm [ C ] Smaller of three times the effective depth and 450 mm [ D ] Smaller of five times the effective depth and 450 mm

Last Answer : [ D ] Smaller of five times the effective depth and 450 mm

A 45-year-old solicitor had an onset of severe, crushing, substernal chest pain while attending a football match. He collapsed on his way to the car. Bystander Cardiorespiratory Resuscitation was begun immediately and continued until arrival in Casualty where an endotracheal tube was inserted and ventilation was maintained on 100% oxygen. Investigations revealed: pH 7.13 PaO2 560 mmHg PaCO2 18 mmHg Bicarbonate 5.8 SaO2 98% Based on these laboratory values, which of the following statements best describes his current pathophysiology? 1) He is demonstrating a primary respiratory alkalosis 2) He probably developed a large right to left intracardiac shunt 3) His anion gap is probably normal 4) His oxyhemoglobin curve is shifted to the left 5) His pulmonary artery pressure is probably elevated

Description : A 45-year-old solicitor had an onset of severe, crushing, substernal chest pain while attending a football match. He collapsed on his way to the car. Bystander Cardiorespiratory Resuscitation ... His oxyhemoglobin curve is shifted to the left 5) His pulmonary artery pressure is probably elevated

Last Answer : Answers-5 This young patient with severe central chest pain has probably arrested due to myocardial infarction and arrhythmia. His gases reveal high PO2 following 100% O2 but severe acidosis ... no left to right shunting and high pulmonary pressures would be expected after this arrest scenario.

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)

Half the angle of nip, (α), for a roll crusher is given by (where, dr, dp and df are diameters of crushing rolls, feed particles and rolls gap respectively). (A) cos α = (dr + dp)/(dr + df) (B) cos α = (dr + df)/(dr + dp) (C) tan α = (dr + dp)/(dr + df) (D) sin α = (dr + dp)/(dr + df)

Description : Half the angle of nip, (α), for a roll crusher is given by (where, dr, dp and df are diameters of crushing rolls, feed particles and rolls gap respectively). (A) cos α = (dr + dp)/(dr + df) (B) cos α = (dr + df)/(dr + dp) (C) tan α = (dr + dp)/(dr + df) (D) sin α = (dr + dp)/(dr + df)

Last Answer : (A) cos α = (dr + dp)/(dr + df)