In a rapid sand filter, air binding is caused due to excessive 

(A) Negative pressure 

(B) Pressure 

(C) Turbidity 

(D) Water pressure

1 Answer

Answer :

(A) Negative pressure

Related questions

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

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

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

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

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

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

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

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

Description : 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

Last Answer : (D) 30 times

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

Description : Turbidity of water may be caused due to  (A) Suspended clay  (B) Suspended silt  (C) Finely divided organic material  (D) All the above 

Last Answer : (D) All the above 

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 

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

Description : Pick up the correct statement from the following: (A) Sand stones may be divided into calcareous, siliceous and ferruginous sand stones (B) Concrete using sand stones, cracks due to excessive shrinkage (C) Broken bricks produce a concrete having good fire resisting qualities (D) All the above

Last Answer : Answer: Option D

Description : Uneven wear of the commutator surface on a direct current propulsion motor can be caused by _____________. A. rapid change in load B. excessive operation at light load C. incorrect brush staggering D. unequal pole spacing

Last Answer : Answer: C

Description : Hardness of water is caused by  (A) Presence of soap lather  (B) Presence of chlorides and sulphates of sodium and potassium  (C) Presence of bicarbonates, sulphates or chlorides of calcium and magnesium  (D) Turbidity 

Last Answer : (C) Presence of bicarbonates, sulphates or chlorides of calcium and magnesium 

Description : Bulking of sand is caused due to (A) Surface moisture (B) Air voids (C) Viscosity (D) Clay contents

Last Answer : Answer: Option A

Description : Pick out the true statement pertaining to water treatment. (A) Slow sand filters can remove colour completely (B) Activated carbon can be used for taste & odour control without subsequent filtration ... of water (D) Normally, the turbidity is removed by adding a coagulant prior to sedimentation

Last Answer : (D) Normally, the turbidity is removed by adding a coagulant prior to sedimentation

Description : . Dechlorination of treated water is necessary to (A) Remove residual turbidity (B) Reduce the bacterial load on filter (C) Control taste and odour (D) Remove chlorinous taste

Last Answer : (D) Remove chlorinous taste

Description : A loud buzzing noise at the contacts of a magnetic controller could indicate _____________. A. weak contact spring pressure B. misalignment of the magnet faces C. excessive line current D. mechanical binding

Last Answer : Answer: B

Description : In water bound macadam roads, binding material, is (A) Sand (B) Stone dust (C) Cement (D) Brick dust

Last Answer : Answer: Option B

Description : In a mortar, the binding material is (A) Cement (B) Sand (C) Surkhi (D) Cinder

Last Answer : Answer: Option A

Description : Disappearance of pink colour of water of a well due of KMnO4 indicates that water contains (A) Acidity (B) Alkalinity (C) Turbidity (D) Organic matter

Last Answer : (D) Organic matter

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 

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

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 

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

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%

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 

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 

Description : Pick up the correct statement from the following: (A) Bulking of sand is caused due to formation of a thin film of surface moisture (B) Fine sand bulks more than coarse sand (C) The volume of fully saturated sand, is equal to the volume of dry and loose sand (D) All the above

Last Answer : Answer: Option D

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

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

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

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

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

Description : The purpose of a surge tank is (A) To control the pressure variations due to rapid changes in the pipe line flow (B) To eliminate water hammer possibilities (C) To regulate flow of water to turbines by providing necessary retarding head of water (D) All of the above

Last Answer : Answer: Option D

Description : Urine turbidity may be caused by any of the following except (A) Phosphates (B) Protein (C) RBC (D) WBC

Last Answer : Answer : B

Description : Rocks formed due to alteration of original structure due to heat and excessive pressure are called (A) Sedimentary rocks (B) Igneous rocks (C) Metamorphic rocks (D) None of these

Last Answer : Answer: Option C

Description : Air filtration typically uses a filter. a. HEPA b. Membrane c. Sand d. Diatomaceous Earth

Last Answer : a. HEPA

Description : One of the generator bearing shells is generally insulated from the end housing in order to prevent _____________. A. rapid brush wear B. residual magnetism leak off C. excessive field winding heat D. circulation of shaft currents

Last Answer : Answer: D

Description : One of the generator or motor bearings is generally insulated from the end housing in order to prevent ________. A. rapid brush wear B. current leakage from the shaft C. excessive field winding heat D. circulation of shaft currents induced in the machine's frame

Last Answer : Answer: D

Description : As far as localised alveolar osteitis is concerned; which one of the following is true? A. The incidence in the mandible and maxilla is similar B. The prophylactic prescription of antibiotics ... and irrigation is mandatory E. Zn oxide eugenol and alvogyl dressing promote a rapid bone growth

Last Answer : C. Excessive fibrinolysis is the likely aetiology

Description : As far as localised alveolar osteitis (dry socket) is concerned; which one of the following is true? M07 A. The incidence in the mandible and maxilla is similar B. The prophylactic ... diagnosis and irrigation is mandatory E. Zinc oxide eugenol and alvogyl dressing promote a rapid bone growth

Last Answer : C. Excessive fibrinolysis is the likely aetiology

Description : Fluorosis is caused due to the presence of excessive amount of __________ in drinking water. (A) Mercury (B) Lead (C) Fluoride (D) Arsenic

Last Answer : (C) Fluoride

Description : Disinfection of drinking water, is done to remove (A) Odour (B) Bacterias (C) Turbidity (D) Colour

Last Answer : (B) Bacterias

Description : Filtration of water is done to remove (A) Colour (B) Odour (C) Turbidity (D) Pathogenic bacteria

Last Answer : (C) Turbidity

Description : Disinfection of drinking water is done to remove (A) Turbidity (B) Odour (C) Colour (D) Bacterias

Last Answer : (D) Bacterias

Description : Hard water for public water supply is discarded because (A) It consumes more soap (B) It contains lot of turbidity (C) It contains pathogenic bacterias (D) It possesses bad taste and odour

Last Answer : (A) It consumes more soap

Description : Low turbidity of water is detected by  (A) Turbidity tube  (B) Jackson turbidity mete (C) Baylis turbidimeter  (D) Hellige turbidimeter 

Last Answer : (C) Baylis turbidimeter