A 30% (by volume) suspension of spherical sand particles in a viscous oil has a hindered settling velocity of 4.44 μm/s. If the Richardson Zaki hindered settling index is 4.5, then the terminal velocity of a sand grain is (A) 0.90 μm/s (B) 1 μm/s (C) 22.1 μm/s (D) 0.02 μm/s

A 30% (by volume) suspension of spherical sand particles in a viscous
oil has a hindered settling velocity of 4.44 μm/s. If the Richardson Zaki
hindered settling index is 4.5, then the terminal velocity of a sand grain is
(A) 0.90 μm/s
(B) 1 μm/s
(C) 22.1 μm/s
(D) 0.02 μm/s
by

1 Answer

Answer :

(B) 1 μm/s
by

Related questions

A suspension of glass beads in ethylene glycol has a hindered settling velocity of 1.7 mm/s, while the terminal settling velocity of a single glass bead in ethylene glycol is 17 mm/s. If the Richardson-Zaki hindered settling index is 4.5, the volume fraction of solids in the suspension is (A) 0.1 (B) 0.4 (C) 0.6 (D) None of these

Description : A suspension of glass beads in ethylene glycol has a hindered settling velocity of 1.7 mm/s, while the terminal settling velocity of a single glass bead in ethylene glycol is 17 mm/s. If the Richardson-Zaki hindered settling index ... in the suspension is (A) 0.1 (B) 0.4 (C) 0.6 (D) None of these

Last Answer : (C) 0.6

For motion of spherical particles in a stationary fluid, the drag co￾efficient in hindered settling compared to that in free settling is (A) More (B) Less (C) Equal (D) More or less, depending on the type of particle

Description : For motion of spherical particles in a stationary fluid, the drag co￾efficient in hindered settling compared to that in free settling is (A) More (B) Less (C) Equal (D) More or less, depending on the type of particle

Last Answer : (A) More

A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system (in SI units) is given below : Δ P/L = 375 × 10 3 VOM + 10.94 × 10 6 V2 OM (SI units) If water is to be used as the fluidising medium, the minimum fluidisation velocity, VOM is (A) 12 mm/s (B) 16 mm/s (C) 24 mm/s (D) 28 mm/s

Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle ... fluidisation velocity, VOM is (A) 12 mm/s (B) 16 mm/s (C) 24 mm/s (D) 28 mm/s

Last Answer : (B) 16 mm/s

The terminal velocity of a small sphere settling in a viscous fluid varies as the (A) First power of its diameter (B) Inverse of the fluid viscosity (C) Inverse square of the diameter (D) Square of the difference in specific weights of solid & fluid

Description : The terminal velocity of a small sphere settling in a viscous fluid varies as the (A) First power of its diameter (B) Inverse of the fluid viscosity (C) Inverse square of the diameter (D) Square of the difference in specific weights of solid & fluid

Last Answer : (B) Inverse of the fluid viscosity

In hindered settling, the particles are (A) Placed farther from the wall (B) Not affected by other particles and the wall (C) Near each other (D) None of these

Description : In hindered settling, the particles are (A) Placed farther from the wall (B) Not affected by other particles and the wall (C) Near each other (D) None of these

Last Answer : (C) Near each othe

A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system (in SI units) is given below: Δ P/L = 375 × 10 3 VOM + 10.94 × 10 6 V2 OM (SI units) If water is to be used as the fluidising medium, in actual operation, the above bed has a height = 1 m. What is the porosity of the fluidised bed? (A) 0.2 (B) 0.5 (C) 0.7 (D) 0.8

Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system ... What is the porosity of the fluidised bed? (A) 0.2 (B) 0.5 (C) 0.7 (D) 0.8

Last Answer : (C) 0.7

When a small spherical body falls in a viscous fluid, its speed increases first, then deceases and eventually it acquires a constant speed called the terminal speed. The terminal speed depends upon (a) The density and viscosity of the fluid (b) The density of the body (c) The diameter of the body (d) All the above parameters

Description : When a small spherical body falls in a viscous fluid, its speed increases first, then deceases and eventually it acquires a constant speed called the terminal speed. The terminal speed depends upon (a) The ... ) The density of the body (c) The diameter of the body (d) All the above parameters

Last Answer : Ans:(d)

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

Drag co-efficient in hindered settling is __________ that in free settling. (A) Less than (B) Equal to (C) Not necessarily greater than (D) Always greater than

Description : Drag co-efficient in hindered settling is __________ that in free settling. (A) Less than (B) Equal to (C) Not necessarily greater than (D) Always greater than

Last Answer : (D) Always greater than

Two particles are called to be equal settling, if they are having the same. (A) Size (B) Specific gravity (C) Terminal velocities in the same fluid & in the same field of force (D) None of these

Description : Two particles are called to be equal settling, if they are having the same. (A) Size (B) Specific gravity (C) Terminal velocities in the same fluid & in the same field of force (D) None of these

Last Answer : (C) Terminal velocities in the same fluid & in the same field of force

Sorting classifiers employing differential settling methods forseparation of particles make use of the differences in their(A) Particle sizes(B) Densities(C) Terminal velocities(D) None of these

Description : Sorting classifiers employing differential settling methods forseparation of particles make use of the differences in their (A) Particle sizes (B) Densities (C) Terminal velocities (D) None of these

Last Answer : (C) Terminal velocities

In classification, particles are said to be equal settling, if they have the same terminal velocities in the (A) Different fluids (B) Same fluid (C) Same field of force (D) Both (B) and (C)

Description : In classification, particles are said to be equal settling, if they have the same terminal velocities in the (A) Different fluids (B) Same fluid (C) Same field of force (D) Both (B) and (C)

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

The settling velocity of a spherical particle of diameter less than 0.1 mm as per Stock’s law, is A. Vs = 418 (Gs – Gw) d [(3T + 70)/100] B. Vs = 418 (Gs – Gw)d² [(3T + 70)/100] C. Vs = 218 (Gs – Gw)d² [(3T + 70)/100] D. Vs = 218 (Gs – Gw)d [(3T + 70)/100]

Description : The settling velocity of a spherical particle of diameter less than 0.1 mm as per Stock’s law, is A. Vs = 418 (Gs – Gw) d [(3T + 70)/100] B. Vs = 418 (Gs – Gw)d² [(3T + 70)/100] C. Vs = 218 (Gs – Gw)d² [(3T + 70)/100] D. Vs = 218 (Gs – Gw)d [(3T + 70)/100]

Last Answer : ANS: B

If the specific gravity of a soil particle of 0.05 cm diameter is 2.67, its terminal velocity while settling in distilled water of viscosity, 0.01 poise, is (A) 0.2200 cm/sec (B) 0.2225 cm/sec (C) 0.2250 cm/sec (D) 0.2275 cm/sec

Description : If the specific gravity of a soil particle of 0.05 cm diameter is 2.67, its terminal velocity while settling in distilled water of viscosity, 0.01 poise, is (A) 0.2200 cm/sec (B) 0.2225 cm/sec (C) 0.2250 cm/sec (D) 0.2275 cm/sec

Last Answer : (D) 0.2275 cm/sec

For a particle settling in water at its terminal settling velocity, which of the following is true? (A) Buoyancy = weight + drag (B) Weight = buoyancy + drag (C) Drag = buoyancy + weight (D) Drag = weight

Description : For a particle settling in water at its terminal settling velocity, which of the following is true? (A) Buoyancy = weight + drag (B) Weight = buoyancy + drag (C) Drag = buoyancy + weight (D) Drag = weight

Last Answer : (B) Weight = buoyancy + drag

The energy required per unit mass to grind limestone particles of very large size to 100 μm is 12.7 kWh/ton. An estimate (using Bond's law) of the energy to grind the particles from a very large size to 50 μm is (A) 6.35 kWh/ton (B) 9.0 kWh/ton (C) 18 kWh/ton (D) 25.4 kWh/ton

Description : The energy required per unit mass to grind limestone particles of very large size to 100 μm is 12.7 kWh/ton. An estimate (using Bond's law) of the energy to grind the particles from a very large size to 50 μm is (A) 6.35 kWh/ton (B) 9.0 kWh/ton (C) 18 kWh/ton (D) 25.4 kWh/ton

Last Answer : (C) 18 kWh/ton

The settling velocity of the particles larger than 0.06 mm in a settling tank of depth 2.4 is 0.33 m per sec. The detention period recommended for the tank, is A. 30 minutes B. 1 hour C. 1 hour and 30 minutes D. 2 hours

Description : The settling velocity of the particles larger than 0.06 mm in a settling tank of depth 2.4 is 0.33 m per sec. The detention period recommended for the tank, is A. 30 minutes B. 1 hour C. 1 hour and 30 minutes D. 2 hours

Last Answer : ANS: D

5-200 μm size particles are called (A) Colloids or aerosols (B) Powder (C) Dust (D) Smoke

Description : 5-200 μm size particles are called (A) Colloids or aerosols (B) Powder (C) Dust (D) Smoke

Last Answer : (A) Colloids or aerosols

Rain drops falling through atmospheric air attain limited terminal velocity, because of (A) Upward thrust due to air (B) Viscous force exerted by air (C) Surface tension effects of water (D) Force of gravity

Description : Rain drops falling through atmospheric air attain limited terminal velocity, because of (A) Upward thrust due to air (B) Viscous force exerted by air (C) Surface tension effects of water (D) Force of gravity

Last Answer : Option B

For the free settling of a spherical particle through a fluid, the slope of, CD-log NRe , plot is (A) 1(B) -1 (C) 0.5 (D) -0.5

Description : For the free settling of a spherical particle through a fluid, the slope of, CD-log NRe , plot is (A) 1 (B) -1 (C) 0.5 (D) -0.5

Last Answer : (B) -1

Stoke's law states that the velocity at which a grain settles out of suspension, the other factors remaining constant, is dependent upon (A) Shape of grain (B) Weight of grain (C) Size of grain (D) Shape, size and weight of grain

Description : Stoke's law states that the velocity at which a grain settles out of suspension, the other factors remaining constant, is dependent upon (A) Shape of grain (B) Weight of grain (C) Size of grain (D) Shape, size and weight of grain

Last Answer : Answer: Option D

Particles having diameter greater than 75 μm (micrometer = 10 -6 mm) are called (A) Grit (B) Dust (C) Powder (D) Smoke

Description : Particles having diameter greater than 75 μm (micrometer = 10 -6 mm) are called (A) Grit (B) Dust (C) Powder (D) Smoke

Last Answer : (A) Grit

Carbonaceous particles having size less than 1 μm are called (A) Grit (B) Aggregates (C) Aerosols (D) Smoke

Description : Carbonaceous particles having size less than 1 μm are called (A) Grit (B) Aggregates (C) Aerosols (D) Smoke

Last Answer : (D) Smoke

A particle A of diameter 10 microns settles in an oil of specific gravity 0.9 and viscosity 10 poise under Stoke's law. A particle B with diameter 20microns settling in the same oil will have a settling velocity (A) Same as that of A (B) One fourth as that of A (C) Twice as that of A (D) Four times as that of A

Description : A particle A of diameter 10 microns settles in an oil of specific gravity 0.9 and viscosity 10 poise under Stoke's law. A particle B with diameter 20microns settling in the same oil will have a settling velocity (A) ... ) One fourth as that of A (C) Twice as that of A (D) Four times as that of A

Last Answer : (B) One fourth as that of A

Forces acting on a particle settling in fluid are __________ forces. (A) Gravitational & buoyant (B) Centrifugal & drag (C) Gravitational or centrifugal buoyant drag (D) External, drag & viscous

Description : Forces acting on a particle settling in fluid are __________ forces. (A) Gravitational & buoyant (B) Centrifugal & drag (C) Gravitational or centrifugal buoyant drag (D) External, drag & viscous

Last Answer : (C) Gravitational or centrifugal buoyant drag

In Newton's law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass varies as the __________ of its diameter. (A) Inverse (B) Square root (C) Second power (D) First power

Description : In Newton's law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass varies as the __________ of its diameter. (A) Inverse (B) Square root (C) Second power (D) First power

Last Answer : (B) Square root

In the Newton's law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass is __________ the fluid viscosity. (A) Directly proportional to (B) Inversely proportional to (C) Inversely proportional to the square root of (D) Independent of

Description : In the Newton's law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass is __________ the fluid viscosity. (A) Directly proportional to (B) Inversely proportional to (C) Inversely proportional to the square root of (D) Independent of

Last Answer : (B) Inversely proportional to

The terminal velocity of a solid spherical particle falling through a stationary fluid mass in the Stoke's law range is proportional to the (A) Inverse of fluid viscosity (B) Square of particle size (C) Difference in the densities of the particle & fluid (D) All (A), (B) and (C)

Description : The terminal velocity of a solid spherical particle falling through a stationary fluid mass in the Stoke's law range is proportional to the (A) Inverse of fluid viscosity (B) Square of particle size (C) Difference in the densities of the particle & fluid (D) All (A), (B) and (C)

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

The capacity of a classifier in 'tons of solid/hr' is given by (where, A = cross-sectional area in m2 , V = rising velocity of fluid in m/sec, S = percentage of solids in the suspension by volume, ρ = density of solids in kg/m3 ) (A) 3.6 AVS.ρ (B) 3.6 A.V.ρ (C) 3.6 A.S. ρ (D) 3.6 AVS/ρ

Description : The capacity of a classifier in 'tons of solid/hr' is given by (where, A = cross-sectional area in m2 , V = rising velocity of fluid in m/sec, S = percentage of solids in the suspension by volume, ρ = density of solids in kg/m3 ) (A) 3.6 AVS.ρ (B) 3.6 A.V.ρ (C) 3.6 A.S. ρ (D) 3.6 AVS/ρ

Last Answer : (A) 3.6 AVS.ρ

The soil which contains finest grain particles, is (A) Coarse sand (B) Fine sand (C) Silt (D) Clay

Description : The soil which contains finest grain particles, is (A) Coarse sand (B) Fine sand (C) Silt (D) Clay

Last Answer : (D) Clay

The force which opposes the relative motion between different layers of liquid or gases is called – (1) Critical Velocity (2) Streamline Flow (3) Terminal Velocity (4) Viscous Force

Description : The force which opposes the relative motion between different layers of liquid or gases is called – (1) Critical Velocity (2) Streamline Flow (3) Terminal Velocity (4) Viscous Force

Last Answer : (4) Viscous Force Explanation: Critical Velocity – The maximum velocity upto which fluid motion is streamline is called Critical Velocity. Streamline Flow – If velocity of all fluid particles is same all the time then it can be said in streamline flow.

The terminal velocity of a sphere setting in a viscous fluid varies as : (a) The Reynolds number (b) The square of its diameter (c) Directly proportional to the viscosity of the fluid (d) Its diameter

Description : The terminal velocity of a sphere setting in a viscous fluid varies as : (a) The Reynolds number (b) The square of its diameter (c) Directly proportional to the viscosity of the fluid (d) Its diameter

Last Answer : (b) The square of its diameter

A sample of natural gas containing 80% methane (CH4 ) and rest nitrogen (N2 ) is burnt with 20% excess air. With 80% of the combustibles producing CO2 and the remainder going to CO, the Orsat analysis in volume percent is (A) CO2 : 6.26, CO : 1.56, O2 : 3.91, H2O :15.66, N2 : 72.60 (B) CO2 : 7.42, CO : 1.86, O2 : 4.64, N2 :86.02 (C) CO2 : 6.39, CO : 1.60, O2 : 3.99, H2O:25.96, N2 :72.06 (D) CO2 : 7.60, CO : 1.90, O2 : 4.75, N2 : 85.74

Description : A sample of natural gas containing 80% methane (CH4 ) and rest nitrogen (N2 ) is burnt with 20% excess air. With 80% of the combustibles producing CO2 and the remainder going to CO, the Orsat analysis in volume percent is (A) CO2 : 6 ... 96, N2 :72.06 (D) CO2 : 7.60, CO : 1.90, O2 : 4.75, N2 : 85.74

Last Answer : (B) CO2 : 7.42, CO : 1.86, O2 : 4.64, N2 :86.02

Pick out the wrong statement. (A) Indian coals on an average contain 25-30% ash as against 10-12% ash in imported coking coal (B) Ammonia is recovered in the form of ammonium sulphate in direct process of by-product recovery (C) A high swelling index number of coking coal indicates poor caking properties of coal (D) Wash oil is used for scrubbing Benzol from coke oven gas

Description : Pick out the wrong statement. (A) Indian coals on an average contain 25-30% ash as against 10-12% ash in imported coking coal (B) Ammonia is recovered in the form of ammonium sulphate in direct ... indicates poor caking properties of coal (D) Wash oil is used for scrubbing Benzol from coke oven gas

Last Answer : (C) A high swelling index number of coking coal indicates poor caking properties of coal

In Newton's law range, the drag co-efficient for the motion of spherical particle in a stationary fluid is (A) 0.44 (B) 0.044 (C) 4.4 (D) 44

Description : In Newton's law range, the drag co-efficient for the motion of spherical particle in a stationary fluid is (A) 0.44 (B) 0.044 (C) 4.4 (D) 44

Last Answer : (A) 0.44

A spherical particle is falling slow in a viscous liquid such that Reynolds number is less than 1. Which statement is correct for this situation? (A) Inertial and drag forces are important (B) Drag, gravitational and buoyancy forces are important (C) Drag force and gravitational forces are important (D) None of the above

Description : A spherical particle is falling slow in a viscous liquid such that Reynolds number is less than 1. Which statement is correct for this situation? (A) Inertial and drag forces are important (B) Drag ... forces are important (C) Drag force and gravitational forces are important (D) None of the above

Last Answer : (B) Drag, gravitational and buoyancy forces are important

A sewer pipe contains 1 mm sand particles of specific gravity 2.65 and 5 mm organic particles of specific gravity 1.2, the minimum velocity required for removing the sewerage, is A. 0.30 m/sec B. 0.35 m/sec C. 0.40 m/sec D. 0.45 m/sec

Description : A sewer pipe contains 1 mm sand particles of specific gravity 2.65 and 5 mm organic particles of specific gravity 1.2, the minimum velocity required for removing the sewerage, is A. 0.30 m/sec B. 0.35 m/sec C. 0.40 m/sec D. 0.45 m/sec

Last Answer : ANS: D

What is 0.02 divided by 2.44?

Description : What is 0.02 divided by 2.44?

Last Answer : 0.0082

The admixture of coarser particles like sand or silt to clay causes (A) Decrease in liquid limit and increase in plasticity index (B) Decrease in liquid limit and no change in plasticity index (C) Decrease in both liquid limit and plasticity index (D) Increase in both liquid limit and plasticity index

Description : The admixture of coarser particles like sand or silt to clay causes (A) Decrease in liquid limit and increase in plasticity index (B) Decrease in liquid limit and no change in plasticity index ... in both liquid limit and plasticity index (D) Increase in both liquid limit and plasticity index

Last Answer : Answer: Option C

The most efficient equipment for the removal of sub-micronic dust particles from blast furnace gas is the (A) Venturi atomiser (B) Gravity settling chamber (C) Electro-static precipitator (D) Cyclone separator

Description : The most efficient equipment for the removal of sub-micronic dust particles from blast furnace gas is the (A) Venturi atomiser (B) Gravity settling chamber (C) Electro-static precipitator (D) Cyclone separator

Last Answer : (C) Electro-static precipitator

Which is the most efficient dust removal equipment for removal of submicronic dust particles from blast furnace gas? (A) Packed scrubber (B) Gravity settling chamber (C) Electrostatic precipitator (D) Hydrocyclone

Description : Which is the most efficient dust removal equipment for removal of submicronic dust particles from blast furnace gas? (A) Packed scrubber (B) Gravity settling chamber (C) Electrostatic precipitator (D) Hydrocyclone

Last Answer : (C) Electrostatic precipitator

A 0.22 M solution of lactic acid (pKa 3.9) was found to contain 0.20 M in the dissociated form and 0.02 M undissociated form, the pH of the solution is (A) 2.9 (B) 3.3 (C) 4.9 (D) 5.4

Description : A 0.22 M solution of lactic acid (pKa 3.9) was found to contain 0.20 M in the dissociated form and 0.02 M undissociated form, the pH of the solution is (A) 2.9 (B) 3.3 (C) 4.9 (D) 5.4

Last Answer : Answer : C

The ratio of the wall drag to the form drag in the Stoke's law range (for motion of spherical particles in a stationary fluid) is (A) 0.5 (B) 1 (C) 2 (D) 0.33

Description : The ratio of the wall drag to the form drag in the Stoke's law range (for motion of spherical particles in a stationary fluid) is (A) 0.5 (B) 1 (C) 2 (D) 0.33

Last Answer : (C) 2

79.93 × 35.02 -59.93 × 85.08 + 74.98 × 44.04 =? a) 1420 b) 1000 c) 1580 d) 870 e) 1260

Description : 79.93 × 35.02 -59.93 × 85.08 + 74.98 × 44.04 =? a) 1420 b) 1000 c) 1580 d) 870 e) 1260

Last Answer : ? ≈ 80 × 35-60 × 85 + 75 × 44 =2800 – 5100 + 3300 = 1000 Answer: b)

Put these in decimal order 22.2,-0.2,2.02 staring with the smallest?

Description : Put these in decimal order 22.2,-0.2,2.02 staring with the smallest?

Last Answer : -0.2

A dumpy level was set up at the midpoint between two pegs A and B, 50 m apart and the staff readings at and were 1.22 and 1.06. With the level set up at , the readings at and were 1.55 and 1.37. The collimation error per 100 m length of sight is (A) 0.02 m inclined upwards (B) 0.04 m inclined downwards (C) 0.04 m inclined upward (D) None of these

Description : A dumpy level was set up at the midpoint between two pegs A and B, 50 m apart and the staff  readings at and were 1.22 and 1.06. With the level set up at , the readings at  and were 1.55 and ... upwards  (B) 0.04 m inclined downwards  (C) 0.04 m inclined upward  (D) None of these

Last Answer : (B) 0.04 m inclined downwards 

What does the name Zaki mean ?

Last Answer : The name Zaki means: talented, intelligent, prudent, talented

What does the name Zaki mean ?

Last Answer : The name Zaki means sharp-witted

Gravity settling tanks/porous filters are used to remove particles larger than

Description : Gravity settling tanks/porous filters are used to remove particles larger than

Last Answer : Gravity settling tanks/porous filters are used to remove particles larger than A. `2 mum ` B. `50 mum` C. `20 mum` D. `10 mum`

The size of clay particles are— (A) 1•0 mm (B) 0•2 – 0•02 mm (C) < 0•02 mm (D) < 0•002 mm

Description : The size of clay particles are— (A) 1•0 mm (B) 0•2 – 0•02 mm (C) < 0•02 mm (D) < 0•002 mm

Last Answer : (D) < 0•002 mm