The yield of a rapid gravity filter as compared to that of slow sand filter, is (A) 10 times (B) 15 times (C) 20 times (D) 30 times

The yield of a rapid gravity filter as compared to that of slow sand filter, is
(A) 10 times
(B) 15 times
(C) 20 times
(D) 30 times
by

1 Answer

Answer :

(D) 30 times
by

Related questions

Rapid gravity filters (A) Were developed by G.W. Fuller (B) Make use of coarser sand with effective size as 0.5 mm (C) Yield as high as 30 times the yield of slow sand filters (D) All the above

Description : Rapid gravity filters  (A) Were developed by G.W. Fuller  (B) Make use of coarser sand with effective size as 0.5 mm  (C) Yield as high as 30 times the yield of slow sand filters  (D) All the above 

Last Answer : (D) All the above 

A high velocity of wash water is required for (A) Rapid gravity filter with strainers (B) Rapid gravity filter without strainers (C) Slow sand filter with strainers (D) Slow sand filter without strainers

Description : A high velocity of wash water is required for (A) Rapid gravity filter with strainers (B) Rapid gravity filter without strainers (C) Slow sand filter with strainers (D) Slow sand filter without strainers

Last Answer : (B) Rapid gravity filter without strainers

Distribution of wash water is provided in (A) Sedimentation tank (B) Slow sand filter (C) Rapid gravity filter (D) All the above

Description : Distribution of wash water is provided in  (A) Sedimentation tank  (B) Slow sand filter  (C) Rapid gravity filter  (D) All the above 

Last Answer : (C) Rapid gravity filter

Slow sand filter is used if maximum turbidity of raw water is less than (A) 10 gm/litre (B) 20 gm/litre (C) 30 gm/litre (D) 50 gm/litre

Description : Slow sand filter is used if maximum turbidity of raw water is less than (A) 10 gm/litre (B) 20 gm/litre (C) 30 gm/litre (D) 50 gm/litre

Last Answer : (D) 50 gm/litre

Rapid sand filter (A) Should be preceded by coagulation and sedimentation (B) Uses rapid sand as filter media(C) Is used after slow sand filtering has been done (D) Can combine disinfection also

Description : Rapid sand filter (A) Should be preceded by coagulation and sedimentation (B) Uses rapid sand as filter media (C) Is used after slow sand filtering has been done (D) Can combine disinfection also

Last Answer : (A) Should be preceded by coagulation and sedimentation

Rapid gravity filter can only remove turbidity of water upto (A) 15 to 25 gm/litre (B) 25 to 30 gm/litre (C) 30 to 35 cm/litre (D) 35 to 40 gm/litre

Description : Rapid gravity filter can only remove turbidity of water upto (A) 15 to 25 gm/litre (B) 25 to 30 gm/litre (C) 30 to 35 cm/litre (D) 35 to 40 gm/litre

Last Answer : (D) 35 to 40 gm/litre

Water filtration rate in a rapid sand filter ranges from __________ kilolitres/m2 /hr. (A) 0.1 to 1 (B) 3 to 6 (C) 10 to 15 (D) 15 to 20

Description : Water filtration rate in a rapid sand filter ranges from __________ kilolitres/m2 /hr. (A) 0.1 to 1 (B) 3 to 6 (C) 10 to 15 (D) 15 to 20

Last Answer : (B) 3 to 6

A slow sand filter is cleaned if its filter head is higher than (A) 10 cm to 20 cm (B) 20 cm to 40 cm (C) 40 cm to 70 cm (D) 70 cm to 120 cm

Description : A slow sand filter is cleaned if its filter head is higher than  (A) 10 cm to 20 cm  (B) 20 cm to 40 cm  (C) 40 cm to 70 cm  (D) 70 cm to 120 cm

Last Answer : (D) 70 cm to 120 cm

A slow sand filter is cleaned if its filter head is higher than (A) 10 cm to 20 cm (B) 20 cm to 40 cm (C) 40 cm to 70 cm (D) 70 cm to 120 cm

Description : A slow sand filter is cleaned if its filter head is higher than (A) 10 cm to 20 cm (B) 20 cm to 40 cm (C) 40 cm to 70 cm (D) 70 cm to 120 cm

Last Answer : (D) 70 cm to 120 cm

Pick up the incorrect statement from the following: (A) The water entering the slow sand filters should be treated by 9.386 coagulants (B) The depth of water on the filter should be twice the depth of the filter sand (C) When the filter head is 0.75 times the depth of filter sand, the water obtained is purest (D) All the above

Description : Pick up the incorrect statement from the following:  (A) The water entering the slow sand filters should be treated by 9.386 coagulants  (B) The depth of water on the filter should be twice the ... is 0.75 times the depth of filter sand, the water obtained is purest  (D) All the above 

Last Answer : (D) All the above 

In rapid sand filters the ratio of length and diameter of the lateral, should not be greater than (A) 10 (B) 15 (C) 20 (D) 25

Description : In rapid sand filters the ratio of length and diameter of the lateral, should not be greater than (A) 10 (B) 15 (C) 20 (D) 25

Last Answer : (C) 20

Water filtration rate in a slow sand filter ranges from __________ litres/m2 /hr. (A) 10 to 20 (B) 100 to 200 (C) 1500 to 2500(D) 4000 to 5000

Description : Water filtration rate in a slow sand filter ranges from __________ litres/m2 /hr. (A) 10 to 20 (B) 100 to 200 (C) 1500 to 2500 (D) 4000 to 5000

Last Answer : (B) 100 to 200

The period of cleaning of a slow sand filter, is usually (A) 5 to 10 days (B) Two weeks to three weeks (C) One month to three months (D) Three months to six months

Description : The period of cleaning of a slow sand filter, is usually (A) 5 to 10 days (B) Two weeks to three weeks (C) One month to three months (D) Three months to six months

Last Answer : (C) One month to three months

The maximum permitted loss of head in a rapid sand filter, is (A) 1 m (B) 2 m (C) 3 m (D) 4 m

Description : The maximum permitted loss of head in a rapid sand filter, is (A) 1 m (B) 2 m (C) 3 m (D) 4 m

Last Answer : (C) 3 m

In a rapid sand filter, air binding is caused due to excessive (A) Negative pressure (B) Pressure (C) Turbidity (D) Water pressure

Description : In a rapid sand filter, air binding is caused due to excessive  (A) Negative pressure  (B) Pressure  (C) Turbidity  (D) Water pressure

Last Answer : (A) Negative pressure

Consider the following statements. The role of the gravel bed in a rapid sand filter is : 1. To filter out large suspended matter 2. To support the sand bed above it 3. To prevent the escape of sand particles 4. To uniformly distribute the backwash water 5. To prevent algae growth Which of the following statements are correct ? a) 1, 2, 3, 4 and 5 b) 2, 3 and 4 only c) 3, 4 and 5 only d) 1, 2 and 3 only

Description : Consider the following statements. The role of the gravel bed in a rapid sand filter is : 1. To filter out large suspended matter 2. To support the sand bed above it 3. To prevent the escape of sand particles 4. To uniformly ... and 5 b) 2, 3 and 4 only c) 3, 4 and 5 only d) 1, 2 and 3 only

Last Answer : b) 2, 3 and 4 only

The weight of a pycnometer containing 400 g sand and water full to the top is 2150 g. The weight of pycnometer full of clean water is 1950 g. If specific gravity of the soil is 2.5, the water content is (A) 5 % (B) 10 % (C) 15 % (D) 20 %

Description : The weight of a pycnometer containing 400 g sand and water full to the top is 2150 g. The weight of pycnometer full of clean water is 1950 g. If specific gravity of the soil is 2.5, the water content is (A) 5 % (B) 10 % (C) 15 % (D) 20 %

Last Answer : (D) 20 %

a rapid gravity filter (A) Raw water from the source is supplied (B) Disinfected raw water is supplied (C) Raw water passed through coagulation tank is supplied (D) None of these

Description : a rapid gravity filter  (A) Raw water from the source is supplied  (B) Disinfected raw water is supplied  (C) Raw water passed through coagulation tank is supplied  (D) None of these

Last Answer : (C) Raw water passed through coagulation tank is supplied 

Which of the following operational problems relate to the functioning of rapid gravity filter ? 1. Inadequate media comprising filter bed 2. Sludge bulking 3. Mud balls 4. Negative head 5. Incrustation of media (a) 1, 3, 4 and 5 only (b) 1, 2, 3 and 4 only (c) 2, 3, 4 and 5 only (d) 1, 2, 3, 4 and 5

Description : Which of the following operational problems relate to the functioning of rapid gravity filter ? 1. Inadequate media comprising filter bed 2. Sludge bulking 3. Mud balls 4. Negative head 5. Incrustation of media (a) 1, 3, 4 and 5 ... 2, 3 and 4 only (c) 2, 3, 4 and 5 only (d) 1, 2, 3, 4 and 5

Last Answer : (a) 1, 3, 4 and 5 only

Efficiency of removing bacterias from raw water by a slow sand filter, is (A) 80% to 81% (B) 85% to 86% (C) 90% to 97% (D) 98% to 99%

Description : Efficiency of removing bacterias from raw water by a slow sand filter, is (A) 80% to 81% (B) 85% to 86% (C) 90% to 97% (D) 98% to 99%

Last Answer : (D) 98% to 99%

After cleaning a slow sand filter, the filtered water is not used for (A) 6 hours to 12 hours (B) 12 hours to 18 hours (C) 18 hours to 24 hours (D) 24 hours to 36 hours

Description : After cleaning a slow sand filter, the filtered water is not used for  (A) 6 hours to 12 hours  (B) 12 hours to 18 hours  (C) 18 hours to 24 hours  (D) 24 hours to 36 hours 

Last Answer : (D) 24 hours to 36 hours 

Insufficient washing of sand grains in a rapid sand filter causes (A) Air binding (B) Shrinkage of filtering media (C) Mud balls (D) Expansion of filtering media

Description : Insufficient washing of sand grains in a rapid sand filter causes (A) Air binding (B) Shrinkage of filtering media (C) Mud balls (D) Expansion of filtering media

Last Answer : (C) Mud balls

To prevent movement of moisture from sub-grade to road pavement at the same level as that of water-table, thickness of a cut off layer of coarse sand, is (A) 15 cm (B) 20 cm (C) 30 cm (D) 45 cm

Description : To prevent movement of moisture from sub-grade to road pavement at the same level as that of water-table, thickness of a cut off layer of coarse sand, is (A) 15 cm (B) 20 cm (C) 30 cm (D) 45 cm

Last Answer : Answer: Option A

To prevent movement of moisture from sub-grade to road pavement on embankments about 0.6 m to 1 m higher than water table, the thickness of cut off layer of coarse sand used, is (A) 15 cm (B) 20 cm (C) 30 cm (D) None of these

Description : To prevent movement of moisture from sub-grade to road pavement on embankments about 0.6 m to 1 m higher than water table, the thickness of cut off layer of coarse sand used, is (A) 15 cm (B) 20 cm (C) 30 cm (D) None of these

Last Answer : Answer: Option D

For classification of potable (drinking) water, we use a __________ filter. (A) Gravity sand (B) Plate and frame (C) Vacuum leaf (D) Rotary vacuum

Description : For classification of potable (drinking) water, we use a __________ filter. (A) Gravity sand (B) Plate and frame (C) Vacuum leaf (D) Rotary vacuum

Last Answer : (A) Gravity sand

Temporary hardness of water can be removed by (A) Addition of alum (a coagulant) (B) Boiling (C) Filtration (through gravity sand filter) (D) Addition of lime

Description : Temporary hardness of water can be removed by (A) Addition of alum (a coagulant) (B) Boiling (C) Filtration (through gravity sand filter) (D) Addition of lime

Last Answer : (B) Boiling

In Pakistan, yield of potato range between : a. 10-15 ton b. 15-20 ton c. 20-25 ton d. 25-30 ton

Description : In Pakistan, yield of potato range between : a. 10-15 ton b. 15-20 ton c. 20-25 ton d. 25-30 ton

Last Answer : 20-25 ton

Percent reduction in grain yield of transplanted rice due to weeds is a). 20-40 b).10-30 c).15-20 d).15-45

Description : Percent reduction in grain yield of transplanted rice due to weeds is a). 20-40 b).10-30 c).15-20 d).15-45

Last Answer : d).15-45

Hardening of cement occurs at (A) Rapid rate during the first few days and afterwards it continues to increase at a decreased rate (B) Slow rate during the first few days and afterwards it continues to increase at a rapid rate (C) Uniform rate throughout its age (D) None of these

Description : Hardening of cement occurs at (A) Rapid rate during the first few days and afterwards it continues to increase at a decreased rate (B) Slow rate during the first few days and afterwards it continues to increase at a rapid rate (C) Uniform rate throughout its age (D) None of these

Last Answer : Answer: Option D

Pick up the correct statement from the following: (A) High percentage of C3S and low percentage of C2S cause rapid hardening (B) High percentage of C3S and low percentage of C2S make the cement less resistive to chemical attack (C) Low percentage of C3S and high percentage of C2S contribute to slow hardening (D) All the above

Description : Pick up the correct statement from the following: (A) High percentage of C3S and low percentage of C2S cause rapid hardening (B) High percentage of C3S and low percentage of C2S make the cement ... ) Low percentage of C3S and high percentage of C2S contribute to slow hardening (D) All the above

Last Answer : Answer: Option D

Quick lime is (i) Slow in setting (ii) Rapid in slacking (iii) Good in strength The correct answer is (A) Only (i) (B) Only (ii) (C) Both (i) and (ii) (D) Both (ii) and (

Description : Quick lime is (i) Slow in setting (ii) Rapid in slacking (iii) Good in strength The correct answer is (A) Only (i) (B) Only (ii) (C) Both (i) and (ii) (D) Both (ii) and (

Last Answer : Answer: Option C

Percent reduction in yield in case of onion due to weeds is a). 20-30 b). 30-35 c). 60-70 d).15-20

Description : Percent reduction in yield in case of onion due to weeds is a). 20-30 b). 30-35 c). 60-70 d).15-20

Last Answer : c). 60-70

Rapid gravity filters can remove bacterial impurities up to a maximum of (A) 50 % (B) 60 % (C) 70 % (D) 80 %

Description : Rapid gravity filters can remove bacterial impurities up to a maximum of  (A) 50 %  (B) 60 %  (C) 70 %  (D) 80 %

Last Answer : (D) 80 %

The strength of concrete after one year as compared to 28 days strength is about (A) 10 to 15% more (B) 15 to 20% more (C) 20 to 25% more (D) 25 to 50% more

Description : The strength of concrete after one year as compared to 28 days strength is about (A) 10 to 15% more (B) 15 to 20% more (C) 20 to 25% more (D) 25 to 50% more

Last Answer : Answer: Option C

A concrete structure is set on fire and the temperature raises to 1000°C. The strength of concrete as compared to original strength reduces to (A) 10 % (B) 15 % (C) 20 % (D) 25 %

Description : A concrete structure is set on fire and the temperature raises to 1000°C. The strength of concrete as compared to original strength reduces to (A) 10 % (B) 15 % (C) 20 % (D) 25 %

Last Answer : Answer: Option C

When compared to ordinary Portland cement, Rapid hardening Portland cement contains ______________ amount of lime content [ A ] Equal [ B ] Greater [ C ] Lesser [ D ] Zero

Description : When compared to ordinary Portland cement, Rapid hardening Portland cement contains ______________ amount of lime content [ A ] Equal [ B ] Greater [ C ] Lesser [ D ] Zero

Last Answer : [ B ] Greater

Mud balls may be removed by (A) Breaking and washing (B) Washing the filter with a solution of caustic soda (C) Removing, cleaning and replacing the damaged sand (D) All the above

Description : Mud balls may be removed by (A) Breaking and washing (B) Washing the filter with a solution of caustic soda (C) Removing, cleaning and replacing the damaged sand (D) All the above

Last Answer : (D) All the above

The U.C. (uniformity coefficient) D60/D10 for the best filter media sand should be (A) 2 (B) 3 (C) 4 (D) 5

Description : The U.C. (uniformity coefficient) D60/D10 for the best filter media sand should be  (A) 2  (B) 3  (C) 4  (D) 5

Last Answer : (A) 2

In slow sand filters, the turbidity of raw water can be removed only up to (A) 60 mg/litre (B) 75 mg/litre (C) 100 gm/litre (D) 150 mg/litre

Description : In slow sand filters, the turbidity of raw water can be removed only up to  (A) 60 mg/litre  (B) 75 mg/litre  (C) 100 gm/litre  (D) 150 mg/litre 

Last Answer : (A) 60 mg/litre 

The bed slope in slow sand filters, is generally kept (A) 1 in 50 (B) 1 in 75 (C) 1 in 100 (D) 1 : 200

Description : The bed slope in slow sand filters, is generally kept  (A) 1 in 50  (B) 1 in 75  (C) 1 in 100  (D) 1 : 200

Last Answer : (C) 1 in 100 

Littoral drift (A) Is the raised line of sand, parallel to the sea coast (B) Is the slow movement of surface water at sea caused by the wind (C) Is a current parallel to the shore, caused due to tangential component of the wind (D) Is a current perpendicular to the shore line caused due to wind

Description : Littoral drift (A) Is the raised line of sand, parallel to the sea coast (B) Is the slow movement of surface water at sea caused by the wind (C) Is a current parallel to the shore, caused due to tangential component of the wind (D) Is a current perpendicular to the shore line caused due to wind

Last Answer : (C) Is a current parallel to the shore, caused due to tangential component of the wind

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

Higher yield may be expected from (A) Gravity springs (B) Surface springs (C) Artesian springs (D) All the above

Description : Higher yield may be expected from (A) Gravity springs (B) Surface springs (C) Artesian springs (D) All the above

Last Answer : (C) Artesian springs

Pick up the correct statement from the following: (A) The volume of underground water extracted by gravity drainage from a saturated soil, is known as yield (B) The ratio of volume drained to the total volume of material drained, is known as specific yield (C) The sum of specific yield and specific retention, is equal to porosity (D) All the above

Description : Pick up the correct statement from the following:  (A) The volume of underground water extracted by gravity drainage from a saturated soil, is  known as yield  (B) The ratio of volume ... ) The sum of specific yield and specific retention, is equal to porosity  (D) All the above

Last Answer : (D) All the above

The quantity of water retained by the sub-soil against gravity, is known (A) Yield (B) Porosity (C) Specific yield (D) Specific retention

Description : The quantity of water retained by the sub-soil against gravity, is known (A) Yield (B) Porosity (C) Specific yield (D) Specific retention

Last Answer : Answer: Option D

Pick up the correct statement from the following: (A) The phenomenon of quicksand generally occurs in the cohesionless soil (B) At critical hydraulic gradient, the saturated sand becomes quick (C) The critical gradient depends on the void ratio and the specific gravity (D) All the above

Description : Pick up the correct statement from the following: (A) The phenomenon of quicksand generally occurs in the cohesionless soil (B) At critical hydraulic gradient, the saturated sand becomes quick (C) The critical gradient depends on the void ratio and the specific gravity (D) All the above

Last Answer : (D) All the above

The hydraulic head that would produce a quick condition in a sand stratum of thickness 1.5 m, specific gravity 2.67 and voids ratio 0.67 is equal to(A) 1.0 m (B) 1.5 m (C) 2.0 m (D) 3 m

Description : The hydraulic head that would produce a quick condition in a sand stratum of thickness 1.5 m, specific gravity 2.67 and voids ratio 0.67 is equal to (A) 1.0 m (B) 1.5 m (C) 2.0 m (D) 3 m

Last Answer : (B) 1.5 m

A coarse-grained soil has a voids ratio 0.75, and specific gravity as 2.75. The critical gradient at which quick sand condition occurs, is (A) 0.25 (B) 0.50 (C) 0.75 (D) 1.00

Description : A coarse-grained soil has a voids ratio 0.75, and specific gravity as 2.75. The critical gradient at which quick sand condition occurs, is (A) 0.25 (B) 0.50 (C) 0.75 (D) 1.00

Last Answer : (D) 1.00

If is specific gravity of sand particles, is porosity, the critically hydraulic gradient (A) ic = (G + 1)/(1 - e) (B) ic = (G + 1)/(1 + e) (C) ic = (G - 1)/(1 + e) (D) ic = (G - 1)/(1 - e)

Description : If is specific gravity of sand particles, is porosity, the critically hydraulic gradient (A) ic = (G + 1)/(1 - e) (B) ic = (G + 1)/(1 + e) (C) ic = (G - 1)/(1 + e) (D) ic = (G - 1)/(1 - e)

Last Answer : Answer: Option C

A Bingham fluid of viscosity μ = 10 Pa.s and yield stress, τ0 = 10 KPa, is shared between flat parallel plates separated by a distance of 10 -3 m. The top plate is moving with a velocity of 1 m/s. The shear stress on the plate is (A) 10 KPa (B) 20 KPa (C) 30 KPa (D) 40 KPa

Description : A Bingham fluid of viscosity μ = 10 Pa.s and yield stress, τ0 = 10 KPa, is shared between flat parallel plates separated by a distance of 10 -3 m. The top plate is moving with a velocity of 1 m/s. The shear stress on the plate is (A) 10 KPa (B) 20 KPa (C) 30 KPa (D) 40 KPa

Last Answer : (B) 20 KPa