Reduction ratio of crushers is the (A) Ratio of feed opening to discharge opening (B) Ratio of discharge opening to feed opening (C) Determining factor for minimum dia of the feed and the product (D) None of these

Reduction ratio of crushers is the
(A) Ratio of feed opening to discharge opening
(B) Ratio of discharge opening to feed opening
(C) Determining factor for minimum dia of the feed and the product
(D) None of these
by

1 Answer

Answer :

(A) Ratio of feed opening to discharge opening
by

Related questions

As per Taggart's formula, the capacity (kg/hr) of Jaw & Gyratory crushers (for gapes of 10 to 60 cms) is equal to (where, L = Length of feed opening, cms S = Maximum width of discharge opening, cms). (A) LS (B) 93 LS (C) 250 LS (D) √(LS)

Description : As per Taggart's formula, the capacity (kg/hr) of Jaw & Gyratory crushers (for gapes of 10 to 60 cms) is equal to (where, L = Length of feed opening, cms S = Maximum width of discharge opening, cms). (A) LS (B) 93 LS (C) 250 LS (D) √(LS)

Last Answer : (B) 93 LS

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

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

The co-efficient of discharge of an orificemeter is a function of (A) Reynolds number at the orifice (B) Ratio of orifice dia to pipe dia (C) Both (A) and (B) (D) None of the above parameters, and has a constant value of 0.61

Description : The co-efficient of discharge of an orificemeter is a function of (A) Reynolds number at the orifice (B) Ratio of orifice dia to pipe dia (C) Both (A) and (B) (D) None of the above parameters, and has a constant value of 0.61

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

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

Gyratory crushers compared to the reciprocating jaw crushers (A) Have greater capacity per unit of discharge area (B) Crush intermittently (C) Are less suitable for coarse materials (D) Have less steady power consumption

Description : Gyratory crushers compared to the reciprocating jaw crushers (A) Have greater capacity per unit of discharge area (B) Crush intermittently (C) Are less suitable for coarse materials (D) Have less steady power consumption

Last Answer : (A) Have greater capacity per unit of discharge area

Pick out the wrong statement. (A) Hammer crushers operate by impact action (B) Standard screens have circular opening (C) With increase in mesh number of screens, their diameter in microns decreases (D) 200 mesh screen has 200 openings per linear cm

Description : Pick out the wrong statement. (A) Hammer crushers operate by impact action (B) Standard screens have circular opening (C) With increase in mesh number of screens, their diameter in microns decreases (D) 200 mesh screen has 200 openings per linear cm

Last Answer : (D) 200 mesh screen has 200 openings per linear cm

Size reduction of __________ is accomplished in steam heated rollers and roll crushers. (A) Resins (B) Gums (C) Hard rubber (D) Waxes

Description : Size reduction of __________ is accomplished in steam heated rollers and roll crushers. (A) Resins (B) Gums (C) Hard rubber (D) Waxes

Last Answer : (C) Hard rubber

Size reduction does not occur due to compression in case of (A) Rod mills (B) Gyratory crushers (C) Jaw crushers (D) Smooth roll crushers

Description : Size reduction does not occur due to compression in case of (A) Rod mills (B) Gyratory crushers (C) Jaw crushers (D) Smooth roll crushers

Last Answer : (A) Rod mills

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

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. (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

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)

Select the correct statement. (A) The discharge through a Venturimeter depends upon Δp only and isindependent of orientation of the meter(B) A Venturimeter with a given gage difference discharges at a greater rate,when the flow is vertically downward through it, than when the flow is verticallyupward(C) For a given pressure difference, the discharge of gas is greater through aVenturimeter, when compressibility is taken into account, than when it isneglected(D) The overall pressure loss is the same in a given pipe line, whether aVenturimeter or a nozzle with the same throat dia is used

Description : Sele(A) The discharge through a Venturimeter depends upon Δp only and isindependent of orientation of the meterct the correct statement. (B) A Venturimeter with a given gage difference discharges at a ... a given pipe line, whether a Venturimeter or a nozzle with the same throat dia is used

Last Answer : (A) The discharge through a Venturimeter depends upon Δp only and isindependent of orientation of the meterct the correct statement

Select the correct statement. (A) The discharge through a Venturimeter depends upon Δp only and isindependent of orientation of the meter(B) A Venturimeter with a given gage difference discharges at a greater rate,when the flow is vertically downward through it, than when the flow is verticallyupward(C) For a given pressure difference, the discharge of gas is greater through aVenturimeter, when compressibility is taken into account, than when it isneglected(D) The overall pressure loss is the same in a given pipe line, whether aVenturimeter or a nozzle with the same throat dia is used

Description : Select the correct statement. (A) The discharge through a Venturimeter depends upon Δp only and isindependent of orientation of the meter (B) A Venturimeter with a given gage difference discharges at a ... a given pipe line, whether a Venturimeter or a nozzle with the same throat dia is used

Last Answer : (A) The discharge through a Venturimeter depends upon Δp only and isindependent of orientation of the meter

Mass flow of granular solid (M) through a circular opening of dia, D follows (A) M ∝ √D (B) M ∝ D2 (C) M ∝ D3 (D) M ∝ D

Description : Mass flow of granular solid (M) through a circular opening of dia, D follows (A) M ∝ √D (B) M ∝ D2 (C) M ∝ D3 (D) M ∝ D

Last Answer : (C) M ∝ D

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)

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

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

Description : 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

Last Answer : (A) Df /Dp

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)

Which of the following achieves the least reduction ratio for a given feed size? (A) Jaw crusher (B) Roll crusher (C) Cone crusher (D) Gyratory crusher

Description : Which of the following achieves the least reduction ratio for a given feed size? (A) Jaw crusher (B) Roll crusher (C) Cone crusher (D) Gyratory crusher

Last Answer : (B) Roll crusher

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

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

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

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

The term 'angle of nip' is concerned with the operation of the __________ crushers. (A) Jaw (B) Roll (C) Gyratory (D) None of these

Description : The term 'angle of nip' is concerned with the operation of the __________ crushers. (A) Jaw (B) Roll (C) Gyratory (D) None of these

Last Answer : (B) Roll

Which of the following crushers can be considered as a combination of a jaw crusher and a roller crusher? (A) Rod mill (B) Fluid energy mill (C) Gyratory crusher (D) Ball mill

Description : Which of the following crushers can be considered as a combination of a jaw crusher and a roller crusher? (A) Rod mill (B) Fluid energy mill (C) Gyratory crusher (D) Ball mill

Last Answer : (C) Gyratory crusher

Basic slag is not ground in (A) Jaw crushers (B) Ball mills

Description : Basic slag is not ground in (A) Jaw crushers (B) Ball mills

Last Answer : (A) Jaw crushers

Capacity (in tons/hr) of jaw/gyratory crusher is equal to (where, L = length of the receiving opening, cm S = greater width of the discharge opening, cm). (A) 0.01 L.S (B) 0.087 L.S (C) L.S (D) L.S/0.087

Description : Capacity (in tons/hr) of jaw/gyratory crusher is equal to (where, L = length of the receiving opening, cm S = greater width of the discharge opening, cm). (A) 0.01 L.S (B) 0.087 L.S (C) L.S (D) L.S/0.087

Last Answer : (B) 0.087 L.S

Cd , Cc and Cv are related (for flow through an orifice) as (where, Cd = discharge co-efficient, Cc = co-efficient of contraction = (area of jet at vena￾contracta/area of opening), Cv = co-efficient of velocity = (actual velocity at vena-contracta/theoretical velocity). (A) Cd = Cc /Cv (B) Cd = Cc .Cv (C) Cd = Cv / Cc (D) None of these

Description : Cd , Cc and Cv are related (for flow through an orifice) as (where, Cd = discharge co-efficient, Cc = co-efficient of contraction = (area of jet at vena￾contracta/area of opening), Cv = co-efficient of velocity = (actual velocity ... A) Cd = Cc /Cv (B) Cd = Cc .Cv (C) Cd = Cv / Cc (D) None of these

Last Answer : (B) Cd = Cc .Cv

Heat balance of furnace provides means of determining the (A) Thermal efficiency of the process (B) Sources of heat losses (C) Scope of reduction of heat losses(D) All (A), (B) and (C)

Description : Heat balance of furnace provides means of determining the (A) Thermal efficiency of the process (B) Sources of heat losses (C) Scope of reduction of heat losses (D) All (A), (B) and (C)

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

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

Description : 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 ... Dry chemicals (C) Heavy tonnages of rocks or gravel (D) Powdered food & granular materials

Last Answer : (C) Heavy tonnages of rocks or gravel

Which can help a producer in determining how much of a product is required the produced? A. Factor-Product Relationship B. Law of Increasing Returns C. Factor-Factor Relationship D. Law of Constant Returns

Description : Which can help a producer in determining how much of a product is required the produced? A. Factor-Product Relationship B. Law of Increasing Returns C. Factor-Factor Relationship D. Law of Constant Returns

Last Answer : C. Chenopodium album

. 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

A distillation column with N plates is being operated under normal conditions. At some point of time, the operation is shifted to total reflux condition (i.e., no product and residue are being withdrawn and feed to the column is stopped). At the new steady state, (A) Composition of vapors and that of liquid do not vary throughout the column (B) Reboiler load and condenser load are minimum (C) The top and bottom compositions are unchanged with and without total reflux (D) The top and bottom compositions correspond to the maximum enrichment available

Description : A distillation column with N plates is being operated under normal conditions. At some point of time, the operation is shifted to total reflux condition (i.e., no product and residue are ... and without total reflux (D) The top and bottom compositions correspond to the maximum enrichment available

Last Answer : (D) The top and bottom compositions correspond to the maximum enrichment available

Which of the following is prohibited by the Code of Professional Ethics for CPAs? a. Use of a firm name which includes the name of a retired partner. b. Accepting an engagement or employment which one cannot reasonably expect to complete or discharge with professional competence. c. Announcement in a newspaper of the opening of a public accounting office. d. Engaging in civic activities during business hours

Description : Which of the following is prohibited by the Code of Professional Ethics for CPAs? a. Use of a firm name which includes the name of a retired partner. b. Accepting an engagement or ... newspaper of the opening of a public accounting office. d. Engaging in civic activities during business hours

Last Answer : Accepting an engagement or employment which one cannot reasonably expect to complete or discharge with professional competence

Fenske equation for determining the minimum number of theoretical stages in distillation column holds good, when the (A) Relative volatility is reasonably constant (B) Mixture (to be separated) shows negative deviation from ideality (C) Mixture (to be separated) shows positive deviation from ideality (D) Multi-component distillation is involved

Description : Fenske equation for determining the minimum number of theoretical stages in distillation column holds good, when the (A) Relative volatility is reasonably constant (B) Mixture (to be separated) ... (to be separated) shows positive deviation from ideality (D) Multi-component distillation is involved

Last Answer : (A) Relative volatility is reasonably constant

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)

Description : 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)

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

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

Scale formation in boiler is controlled by (A) Preheating of feed water (B) Reduction in hardness, silica & alumina in feed water (C) Keeping the pH value of feed water just below 7 (D) Eliminating H2S in feed water

Description : Scale formation in boiler is controlled by (A) Preheating of feed water (B) Reduction in hardness, silica & alumina in feed water (C) Keeping the pH value of feed water just below 7 (D) Eliminating H2S in feed water

Last Answer : (B) Reduction in hardness, silica & alumina in feed water

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)

Pulverised coal passing through 200 mesh screen has a diameter of 0.074 mm (74 micron). The same passing through 50 mesh screen will have a dia of __________ mm. (A) 0.007 (B) 0.30 (C) 50 (D) 0.014

Description : Pulverised coal passing through 200 mesh screen has a diameter of 0.074 mm (74 micron). The same passing through 50 mesh screen will have a dia of __________ mm. (A) 0.007 (B) 0.30 (C) 50 (D) 0.014

Last Answer : (B) 0.30

What is the critical rotation speed in revolutions per second, for a ball mill of 1.2 m diameter charged with 70 mm dia balls? (A) 0.5 (B) 1.0 (C) 2.76 (D) 0.66

Description : What is the critical rotation speed in revolutions per second, for a ball mill of 1.2 m diameter charged with 70 mm dia balls? (A) 0.5 (B) 1.0 (C) 2.76 (D) 0.66

Last Answer : (D) 0.66

. The most suitable equipment for removing the fine dust particle (< 1 micron dia.) from air below its dew point will be a/an (A) Bag filter (B) Electrostatic precipitator (C) Cyclone separator (D) Wet scrubber

Description : . The most suitable equipment for removing the fine dust particle (< 1 micron dia.) from air below its dew point will be a/an (A) Bag filter (B) Electrostatic precipitator (C) Cyclone separator (D) Wet scrubber

Last Answer : (B) Electrostatic precipitator

The critical speed of a trommel (N) is related to its dia (D) as (A) N ∝ 1/√D (B) N ∝ √D (C) N ∝ D (D) N ∝ 1/D

Description : The critical speed of a trommel (N) is related to its dia (D) as (A) N ∝ 1/√D (B) N ∝ √D (C) N ∝ D (D) N ∝ 1/D

Last Answer : (A) N ∝ 1/√D

Small dia distillation column can be a (A) Packed column (B) Sieve tray (C) Bubble cap (D) Any of these

Description : Small dia distillation column can be a (A) Packed column (B) Sieve tray (C) Bubble cap (D) Any of these

Last Answer : (A) Packed column

Tray spacing in a distillation column of dia 10-12 ft. used in petroleum refinery may be around __________ inches. (A) 5 (B) 30 (C) 60 (D) 100

Description : Tray spacing in a distillation column of dia 10-12 ft. used in petroleum refinery may be around __________ inches. (A) 5 (B) 30 (C) 60 (D) 100

Last Answer : (B) 30

A metal wire of 0.01 m dia and thermal conductivity 200 W/m.K is exposed to a fluid stream with a convective heat transfer coefficient of 100 W/m2 .K. The Biot number is (A) 5.6 (B) 0.025 (C) 3.5 (D) 0.0035

Description : A metal wire of 0.01 m dia and thermal conductivity 200 W/m.K is exposed to a fluid stream with a convective heat transfer coefficient of 100 W/m2 .K. The Biot number is (A) 5.6 (B) 0.025 (C) 3.5 (D) 0.0035

Last Answer : (B) 0.025

A fluid (µ/ρ) = 0.01 cm2 /sec is moving at critical flow condition (NRe = 2100) through a pipe of dia 3 cms. Velocity of flow is __________ cm/sec. (A) 7 (B) 700 (C) 7000 (D) 630

Description : A fluid (µ/ρ) = 0.01 cm2 /sec is moving at critical flow condition (NRe = 2100) through a pipe of dia 3 cms. Velocity of flow is __________ cm/sec. (A) 7 (B) 700 (C) 7000 (D) 630

Last Answer : (A) 7