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

1 Answer

Answer :

(A) The new surface created

Related questions

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

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

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 )

Description : Which of the following gives the crushing energy required to create new surface ? (A) Taggarts rule (B) Fick's law (C) Rittinger's Law (D) None of these

Last Answer : (C) Rittinger's Law

Description : Which of the following gives the work required for size reduction of coal to -200 mesh in a ball mill most accurately? (A) Rittinger's law (B) Kick's law (C) Bond's law (D) None of these

Last Answer : (A) Rittinger's law

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)

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

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 )

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

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)

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

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

Description : . Kick's law assumes that the energy required for size reduction is proportional to the logarithm of the ratio between the initial and the final diameters. The unit of Kick's constant is (A) kW. sec/kg (B) kWh/kg (C) kWh/sec. kg (D) kg/sec

Last Answer : (A) kW. sec/kg

Description : Rittinger's number designates the new surface created per unit mechanical energy absorbed by the material being crushed. Larger value of Rittinger's number of a material indicates its (A) Easier grindability (B) Poor grindability (C) High power consumption in grinding (D) None of these

Last Answer : (A) Easier grindability

Description : The work index in Bond's law for crushing of solids has the following dimensions (A) No units (dimensionless) (B) kWh/ton (C) kW/ton (D) kWh.m1/2 /ton

Last Answer : (B) kWh/ton

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)

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)

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

Description : Crushing efficiency is the ratio of the (A) Surface energy created by crushing to the energy absorbed by the solid (B) Energy absorbed by the solid to that fed to the machine (C) Energy ... surface energy created by crushing (D) Energy absorbed by the solid to the surface energy created by crushing

Last Answer : (A) Surface energy created by crushing to the energy absorbed by the solid

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)

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

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

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

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

Description : 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

Last Answer : (B) Secondary

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

Description : For most solids, the coefficient of volume expansion is _________ the coefficient of linear expansion.  a. unrelated to  b. proportional to  c. twice  d. three times

Last Answer : three times

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

Description : Pick out the wrong statement. (A) The equivalent stiffness of two springs (of equal stiffness 'S') in series is S/2 while in parallel is 2S (B) For a helical spring, deflection is ... is less than the buckling load (D) Modulus of resilience is proportional to (stress at elastic limit)2

Last Answer : (C) Crushing load or columns is less than the buckling load

Description : Sensitivity of a soil can be defined as (A) Percentage of volume change of soil under saturated condition (B) Ratio of compressive strength of unconfined undisturbed soil to that of soil in a remoulded state (C) Ratio of volume of voids to volume of solids (D) None of the above

Last Answer : Answer: Option B

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

Description : Assertion A: Large size stones are required in stone revetment in shore protection. Reason R: Resistance of stone to wave force is proportional to its volume and wave force is proportional to the exposed area of the stone. ... of A (C) A is true but R is false (D) A is false but R is true

Last Answer : (A) Both A and R is true and R is the correct explanation of A

Description : Boyle's law states that A. pressure of a gas is inversely proportional to its volume i.e. P V = constant B. pressure of a gas is directly proportional to its volume i.e. P⁄V = constant C. ... of a gas is directly proportional to the square of its volume i.e. P ⁄ V² = constant

Last Answer : pressure of a gas is inversely proportional to its volume i.e. P × V = constant

Description : What Law states that the pressure of gas is inversely proportional to its volume at constant temperature?  a. Charles’ law  b. Gay-Lussac’s Law  c. Boyle’s Law  d. Dalton’s Law

Last Answer : Boyle’s Law

Description : The following are true: a. Kirschman's law: the greatest contrast in colour is seen when the luminosity differnece is small b. Emmbert's law: the perceived size of an object varies in ... image in the periphery of the retina tends to fade or disappear during steady fixation of another objec

Last Answer : Troxler's phenomenon: an image in the periphery of the retina tends to fade or disappear during steady fixation of another objec

Description : Pick out the material having minimum Rittinger's number. (A) Calcite (B) Pyrite (C) Quartz (D) Galena

Last Answer : (C) Quartz

Description : In reactions involving solids and liquids (where change in volume is negligible), the heat of reaction at constant pressure as compared to that at constant volume is (A) More (B) Less (C) Same (D) Unpredictable; depends on the particular reaction

Last Answer : (C) Same

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

Last Answer : (C) Compression

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)

Description : The ratio of the weight of given volume of soil solids to the weight of an equal volume of distilled water at the given temperature, is known (A) Porosity (B) Specific gravity (C) Void ratio (D) Water content

Last Answer : (B) Specific gravity

Description : The ratio of the volume of voids to the volume of soil solids in a given soil mass, is known (A) Porosity (B) Specific gravity (C) Void ratio (D) Water content

Last Answer : (C) Void ratio

Description : If the volume of voids is equal to the volume of solids in a soil mass, then the values of porosity and voids ratio respectively are (A) 1.0 and 0.0 (B) 0.0 and 1.0 (C) 0.5 and 1.0 (D) 1.0 and 0.5

Last Answer : (C) 0.5 and 1.0

Description : The water content of soil is defined as the ratio of (A) Volume of water to volume of given soil (B) Volume of water to volume of voids in soil (C) Weight of water to weight of air in voids (D) Weight of water to weight of solids of given mass of soil

Last Answer : Answer: Option D

Description : Pick up the correct statement from the following: (A) The void ratio in soils is defined as the ratio of the volume of voids to the volume of solids (B) The bulk density of a soil is defined as the ... of a soil is defined as weight of solids to the total volume of the soil (D) All the above

Last Answer : Answer: Option D

Description : In case of laminar flow of fluid through a circular pipe, the (A) Shear stress over the cross-section is proportional to the distance from the surface of the pipe (B) Surface of velocity distribution is a ... occurs at a radial distance of 0.5 r from the centre of the pipe (r = pipe radius)

Last Answer : (B) Surface of velocity distribution is a paraboloid of revolution, whose volume equals half the volume of circumscribing cylinder

Description : Solidification time of a molten metal in a casting is proportional to (where, V = volume of metal & A = its surface area; in the casting) (A) V/A (B) V/A2 (C) V2/A (D) V2/A2

Last Answer : (D) V2/A2

Description : Rittinger number which designates the new surface produced per unit of mechanical energy absorbed by the material being crushed, depends on the (A) State or manner of application of the crushing force (B) Ultimate strength of the material (C) Elastic constant of the material (D) All (A), (B) and (C)

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

Description : Pick out the correct statement. (A) Fanning friction factor is inversely proportional to Reynolds number always (B) The property of a randomly packed bed (with raschig rings) is given by the ratio of the ... the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow

Last Answer : (D) Mach number is given by the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow

Description : The time taken for gravity flow of a fixed volume of liquid (as in Redwood viscometer) is directly proportional to its (A) Absolute viscosity (B) Ratio of absolute viscosity to density (C) Density (D) Reynolds number

Last Answer : (B) Ratio of absolute viscosity to density