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

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 

by

1 Answer

Answer :

(D) 24 hours to 36 hours 

by

Related questions

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

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

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

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

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%

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

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 

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

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

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

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 best quality of filter material is obtained from quartzite if it does not loose weight when placed in hydrochloric acid for 24 hours, more than (A) 5 % (B) 8 % (C) 10 % (D) 12 %

Description : The best quality of filter material is obtained from quartzite if it does not loose weight when  placed in hydrochloric acid for 24 hours, more than  (A) 5 %  (B) 8 %  (C) 10 %  (D) 12 % 

Last Answer : (A) 5 % 

At the time of marriage, a man was 6 years older to his wife. 12 years after their marriage, his age is 6/5 times the age of his wife. What was wife’s age at the time of marriage? a) 18 years b) 24 years c) 30 years d) 36 years e) None of these

Description : At the time of marriage, a man was 6 years older to his wife. 12 years after their marriage, his age is 6/5 times the age of his wife. What was wife’s age at the time of marriage? a) 18 years b) 24 years c) 30 years d) 36 years e) None of these

Last Answer : ratio of their ages, 12 years hence = 6 : 5  Difference in ages = 1 ratio = 6 years wife’s age (12 years hence) = 5 ratio = 5 × 6 years = 30 years wife’s age at the time of marriage = 30 – 12 = 18 years Answer: a)

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50'. What number is missing? -Riddles

Description : 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50'. What number is missing? -Riddles

Last Answer : 22

The time taken for a radioactive element to reduce to 50% of its original weight is __________ years, if its half life period is 12 years. (A) 24 (B) 18 (C) 6 (D) 36

Description : The time taken for a radioactive element to reduce to 50% of its original weight is __________ years, if its half life period is 12 years. (A) 24 (B) 18 (C) 6 (D) 36

Last Answer : (B) 18

Surface preparation for Metallising the abrasives used for final cleaning is a) Chilled iron grit G.24, as defined in BS : 2451 b) Washed salt free angular silica sand of mesh size 12 to 30 with a minimum of 40% retained on a 20 mesh c) either (a) or (b) * d) d) neither (a) or (b)

Description : Surface preparation for Metallising the abrasives used for final cleaning is a) Chilled iron grit G.24, as defined in BS : 2451 b) Washed salt free angular silica sand of mesh size 12 to 30 with a minimum of 40% retained on a 20 mesh c) either (a) or (b) * d) d) neither (a) or (b)

Last Answer : c) either (a) or (b) *

The mean of the ages of father and his son is 27 years. After 18 years, father will be twice as old as his son. Their present ages are (A) 42, 12 (B) 40, 14 (C) 30, 24 (D) 36, 18

Description : The mean of the ages of father and his son is 27 years. After 18 years, father will be twice as old as his son. Their present ages are (A) 42, 12 (B) 40, 14 (C) 30, 24 (D) 36, 18

Last Answer : Answer: A

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

Assertion `:` Lymph is the filtered blood from capillaries, which is rich in oxygen, but devoid of RBC. Reason `:` RBC can filter out due to small dia

Description : Assertion `:` Lymph is the filtered blood from capillaries, which is rich in oxygen, but devoid of RBC. Reason `:` RBC can filter out due to small dia

Last Answer : Assertion `:` Lymph is the filtered blood from capillaries, which is rich in oxygen, but devoid of RBC ... . D. If both Assertion & Reason are false.

Gelatinous solid (which plug the septum) can be filtered by a __________ filter. (A) Sparkler (B) Plate and frame (C) Vacuum leaf (D) Pre-coat

Description : Gelatinous solid (which plug the septum) can be filtered by a __________ filter. (A) Sparkler (B) Plate and frame (C) Vacuum leaf (D) Pre-coat

Last Answer : (D) Pre-coat

The detention period for plain sedimentation water tanks, is usually (A) 4 to 8 hours (B) 8 to 16 hours (C) 16 to 24 hours (D) 24 to 36 hours

Description : The detention period for plain sedimentation water tanks, is usually  (A) 4 to 8 hours  (B) 8 to 16 hours  (C) 16 to 24 hours  (D) 24 to 36 hours

Last Answer : (D) 24 to 36 hours

The maximum time lag between surface preparation and the application of primer coat shall not exceed a) 12 hours b) 24 hours* c) 48 hours d) 36 hours

Description : The maximum time lag between surface preparation and the application of primer coat shall not exceed a) 12 hours b) 24 hours* c) 48 hours d) 36 hours

Last Answer : b) 24 hours*

The emergency electrical power source on tank vessels over 500 GT on an international voyage, should be capable of continuous operation under emergency load for _____________. A. 6 hours B. 12 hours C. 18 hours D. 24 hours

Description : The emergency electrical power source on tank vessels over 500 GT on an international voyage, should be capable of continuous operation under emergency load for _____________. A. 6 hours B. 12 hours C. 18 hours D. 24 hours

Last Answer : Answer: C

In the arrangement shown below, two trucks A and B are held in position with spring compressed. When they are released and the spring has fallen away, A is found to be moving to the left at 2 m/s. The energy stored in the compressed spring was (a) 12 J (b) 24 J (c) 18 J (d) 36 J

Description : In the arrangement shown below, two trucks A and B are held in position with spring compressed. When they are released and the spring has fallen away, A is found to be moving to the left at 2 m/s. The energy stored in the compressed spring was (a) 12 J (b) 24 J (c) 18 J (d) 36 J

Last Answer : Ans:(b) Direction: In the following question, a statement of Assertion (A) is given followed by corresponding Reason (R), just below it. Read the statements carefully and mark the correct answer: (a) If both A and ... true but R is not the correct explanation of A. (c) If A is true but R is false

5, 8, 12, 18, 24, 30, 36, 42, ____ a) 52 b) 46 c) 48 d) 54 e) 56

Description : 5, 8, 12, 18, 24, 30, 36, 42, ____ a) 52 b) 46 c) 48 d) 54 e) 56

Last Answer : Each term in the series is the addition of successive prime numbers. Like Prime numbers are2, 3, 5, 7, 11, 13, 17, 19, 23, 29 and so on. So first term is addition of (2 + 3). Ie 5, then second term is (3 + 5) ie ... +17)ie. 30, then (17+19)ie.36, then (19+23)ie., 42, then (23+29)i.e. 52. Answer: a)

In the sequence of numbers 8, 24, 12, X, 18, 54 the missing number X is : (A) 26 (B) 24 (C) 36 (D) 32

Description : In the sequence of numbers 8, 24, 12, X, 18, 54 the missing number X is : (A) 26 (B) 24 (C) 36 (D) 32

Last Answer : Answer: C In the sequence of numbers 8, 24, 12, X, 18, 54 8*3= 24, 12*3= 36, 18*3= 54, i.e multiple of 3.

Insert the missing number: 8 24 12 ? 18 54 (A) 26 (B) 24 (C) 36 (D) 32

Description : Insert the missing number: 8 24 12 ? 18 54 (A) 26 (B) 24 (C) 36 (D) 32

Last Answer : Answer: C Explanation: Numbers are alternatively multiplied by 3 and divided by 2. So, the next number = 3 x 12 = 36, 36 ÷ 2 = 18

X and Y can do a job in 24 days, Y & Z can do the same job in 36 days. X,Y,Z together can finish it in 18 days. X and Z together will do it in. a) 24 b) 36 c) 12 d) 26

Description : X and Y can do a job in 24 days, Y & Z can do the same job in 36 days. X,Y,Z together can finish it in 18 days. X and Z together will do it in. a) 24 b) 36 c) 12 d) 26

Last Answer : A (X+Y+Z) s 1 day work =1/18 (X+Y)'s 1 day work = 1/24 (Y+Z)'s 1 day work = 1/36 (X+Z)'s 1 day work = 2[X+Y+Z]'s 1 day work - [(X+Y)'s 1 day work + (Y+Z)'s 1 day work]= 2 [1/18]- (1/24 + ... /24 + 1/36) = 1/9 -1/24 - 1/36 =(8-3-2)/72 =3/72 = 1/24 So X & Z together will do the work in 24 days

The length of lap in tension reinforcement should not be less than the bar diameter × (actual tension / four times the permissible average bond stress) if it is more than (A) 18 bar diameters (B) 24 bar diameters (C) 30 bar diameters (D) 36 bar diameters

Description : The length of lap in tension reinforcement should not be less than the bar diameter × (actual tension / four times the permissible average bond stress) if it is more than (A) 18 bar diameters (B) 24 bar diameters (C) 30 bar diameters (D) 36 bar diameters

Last Answer : Answer: Option C

Lapped splices in tensile reinforcement are generally not used for bars of size larger than (A) 18 mm diameter (B) 24 mm diameter (C) 30 mm diameter (D) 36 mm diameter

Description : Lapped splices in tensile reinforcement are generally not used for bars of size larger than (A) 18 mm diameter (B) 24 mm diameter (C) 30 mm diameter (D) 36 mm diameter

Last Answer : Answer: Option D

how much sand do i need for my sand filter for a 24 foot pool?

Description : how much sand do i need for my sand filter for a 24 foot pool?

Last Answer : The best thing to do is to locate the manufacturer on the filter. Sometimes the amount of sand is listed right on the filter next to this name. If it is not, you need to contact the manufacturer as all filters are somewhat different. An average would be 200-250 pounds.

Incubation period for infectious coryza is B A. long duration (weeks) B. short duration (18-36 hours) C. Very short duration (3-6 hours) D. None of these

Description : Incubation period for infectious coryza is B A. long duration (weeks) B. short duration (18-36 hours) C. Very short duration (3-6 hours) D. None of these

Last Answer : short duration (18-36 hours)

The odd numbers from 1 to 45 which are exactly divisible by 3 are arranged in an ascending order. The number at 6 th position is (A) 18 (B) 24 (C) 33 (D) 36

Description : The odd numbers from 1 to 45 which are exactly divisible by 3 are arranged in an ascending order. The number at 6 th position is (A) 18 (B) 24 (C) 33 (D) 36

Last Answer : Answer: C

The diameter of pipes in bath rooms and lavatories in domestic water supply, is (A) 6 mm (B) 12 mm (C) 18 mm (D) 24 mm

Description : The diameter of pipes in bath rooms and lavatories in domestic water supply, is (A) 6 mm (B) 12 mm (C) 18 mm (D) 24 mm

Last Answer : (B) 12 mm

In man, the amount of calcium in gms filtered in 24 hrs period by the renal glomeruli is (A) 5 (B) 10 (C) 15 (D) 20

Description : In man, the amount of calcium in gms filtered in 24 hrs period by the renal glomeruli is (A) 5 (B) 10 (C) 15 (D) 20

Last Answer : Answer : B

BIRMINGHAM EGBB/BHX SA0850 280850 18014kt 9999 SCT024 BKN030 BKN045 12/08 Q1011 = FC0600 280600Z 280816 190015G27kt 9999 BKN025 TEMPO 0812 5000 – DZ BKN012 BECMG 1214 19022G37 = FT0400 280434Z 281212 19022G37 9999 BKN025 TEMPO 1902 5000 RA BKN010 BECMG 2201 25007kt Refer to weather information for Birmingham above. What is the total time for which the weather is forecast? a. 9 hours b. 18 hours c. 24 hours d. 28 hours

Description : BIRMINGHAM EGBB/BHX SA0850 280850 18014kt 9999 SCT024 BKN030 BKN045 12/08 Q1011 = FC0600 280600Z 280816 190015G27kt 9999 BKN025 TEMPO 0812 5000 - DZ BKN012 BECMG 1214 19022G37 = FT0400 280434Z 281212 19022G37 9999 ... weather is forecast? a. 9 hours b. 18 hours c. 24 hours d. 28 hours

Last Answer : d. 28 hours

There is a circular path around a sports field. Priya takes 18 minutes to drive one round of the field. Harish takes 12 minutes. Suppose they both start at the same point and at the same time and go in the same direction. After how many minutes will they meet ? (a) 36 minutes (b) 18 minutes (c) 6 minutes (d) They will not meet

Description : There is a circular path around a sports field. Priya takes 18 minutes to drive one round of the field. Harish takes 12 minutes. Suppose they both start at the same point and at the same time and go in the same ... will they meet ? (a) 36 minutes (b) 18 minutes (c) 6 minutes (d) They will not meet

Last Answer : (a) 36 minutes

Consider the following statements: Maximum slenderness ratio of load-bearing masonry walls for a dwelling having more than two storeys shall not exceed. 1. 12, if lime mortar is used 2. 18, if cement-lime mortar 1:2:9 is used 3. 24, if cement mortar 1:6 is used\ Which of these statements are correct? (a) 1 and 2 only b) 2 and 3 only c) 1 and 3 only d)1, 2 and 3

Description : Consider the following statements: Maximum slenderness ratio of load-bearing masonry walls for a dwelling having more than two storeys shall not exceed. 1. 12, if lime mortar is used 2. 18, if cement-lime mortar 1:2:9 is used 3. 24, ... ? (a) 1 and 2 only b) 2 and 3 only c) 1 and 3 only d)1, 2 and 3

Last Answer : b) 2 and 3 only

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 detention period for plain sedimentation water tanks, is usually A. 4 to 8 hours B. 8 to 16 hours C. 16 to 24 hours D. 24 to 36 hours

Description : The detention period for plain sedimentation water tanks, is usually A. 4 to 8 hours B. 8 to 16 hours C. 16 to 24 hours D. 24 to 36 hours

Last Answer : ANS: A

There is a bridge besides a river. Two friends Arun and varun started their journey from place L, moved to the garden located at another place M & then returned to place L. Arun moves by swimming at a speed of 30 km/hr while Varun sails on a boat at a speed of about 24km/hr. If the flow of water current is at the speed of 12km/hr, what will be the average speed of boat sailor? A) 36 B) 18 C) 24 D) 48

Description : There is a bridge besides a river. Two friends Arun and varun started their journey from place L, moved to the garden located at another place M & then returned to place L. Arun moves by swimming at a speed of 30 ... 12km/hr, what will be the average speed of boat sailor? A) 36 B) 18 C) 24 D) 48 

Last Answer : ANSWER:B Explanation: As Arun swims both the ways at the speed of 30km/hr, the average speed of swimming is 30 km/hr Being a boat sailor, varun moves downstream at speed =24 +12=36km/hr and upstream at speed = 24-12= ... Upstream Speed])] = (36*12)/0.5(36+12) km/hr = 432/24 km/hr = 18 km/hr

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 

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

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

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

All electioneering campaigns during the time of elections are stopped. (1) 48 hours before the appointed time of election results (2) 48 hours before the actual poll (3) 24 hours before the actual poll (4) 36 hours before the actual poll

Description : All electioneering campaigns during the time of elections are stopped. (1) 48 hours before the appointed time of election results (2) 48 hours before the actual poll (3) 24 hours before the actual poll (4) 36 hours before the actual poll

Last Answer : (4) 36 hours before the actual poll

Carcasses are chilled for 24 to ____ hours before being graded and processed. a. 36 c. 72 b. 48 d. 96

Description : Carcasses are chilled for 24 to ____ hours before being graded and processed. a. 36 c. 72 b. 48 d. 96

Last Answer : b. 48

All raw milk must be processed within ____ hours of receipt at the processing plant. a. 24 c. 48 b. 36 d. 72

Description : All raw milk must be processed within ____ hours of receipt at the processing plant. a. 24 c. 48 b. 36 d. 72

Last Answer : d. 72