A. 200 litres

C. 100 litres

D. 165 litres

A. main sewer

C. submain sewer

D. lateral sewer

A. back washing in slow sand filters

B. correct answer is

C. scraping and removal in filters rapid sand

D. back washing in rapid sand filters</strong>

A. directly proportional to BOD satisfied

B. inversely proportional to BOD re-maining

D. inversely proportional to BOD satisfied

A. partially separate system

B. combined system

D. partially combined system

A. ring system

B. dead end system

C. radial system

B. 40 to 50

C. 10 to 15

D. 20 to 25

A. arithmetical increase method

B. incremental increase method

D. graphical method

B. electrical analysis method

C. equivalent pipe method

D. Hardy cross method

A. pressure relief valve

C. air relief valve

D. sluice valve

A. 5 day BOD is greater than 4 day BOD keeping other conditions same

B. 5 day BOD is the ultimate BOD

C. BOD does nof depend on time

B. 150000m3

C. 180000m3

D. 100000m3

B. 15 to 30 cm/sec.

C. 15 to 30 cm/hour

D. 5 to 10 cm/sec.

A. contains pathogenic bacteria

C. is contaminated

D. is safe and suitable for drinking and domestic use

A. the depth of tank is decreased

B. particle size is decreased

D. the surface area of tank is increased

A. 0

C. infinity

D. none of the above

A. higher temperature

B. sunlight

D. satisfying oxygen demand

A. correct answer is?

B. decrease in turbidity of water

D. decrease in temperature of water</strong>

E. increase in temperature of water

B. lesser efficiency in removal of bacteria

C. higher efficiency in removal of bacteria </strong>

D. higher filtration rate

E. correct answer is?

B. the effluent cannot be reduced to zero hardness

C. it is unsuitable for turbid and acidic water

D. it is unsuitable for softening the water of excessive hardness

A. increased at higher pH value of water

B. highest at pH value equal to 7

C. unaffected by pH value of water

A. sum of applied and residual chlorine

B. residual chlorine

C. applied chlorine

B. re R is the radius of influence

C. at a distance R/2 from the well

D. none of the above

E. at a distance R from the well

A. intercepting sewer

B. submain sewer

D. house sewer

A. circular sewer

B. horse-shoe type sewer

D. semi-elliptical sewer

A. aerobic in lower compartment and anaerobic in upper compartment

B. aerobic only

D. anaerobic only

B. parasitic

C. anaerobic

D. pathogenic

B. same

C. none of the above

D. larger

B. dissolved impurities

C. both suspended and dissolved impurities

D. none of the above

A. total hardness total alkalinity

C. total hardness

D. non carbonate hardness

A. 12 hours

B. 2-4 hours

D. 5 minutes

A. 2 to 4

B. 8 to 10

C. 4 to 6

B. none of the above

C. nitrification

D. oxidation

A. 3-Jan

B. 4-Mar

C. 1

A. dissolved oxygen

B. chlorine

C. nitrogen

A. sodium sulphate

C. sodium chloride

D. calcium chloride

B. 500 litres/sec

C. 1000 litres/see

D. 5 litres/sec

A. presence of oxygen only

B. absence of oxygen only

C. presence of water

B. Both A and R are true but R is not the correct explanation of A

C. A is true but R is false

D. A is false but R is true

B. rainfall + 6 DWF

C. equal to rainfall

D. rainfall + DWF

A. 100

C. 10 to 25

D. 50

A. none of the above

B. less than HMD when flowing full

D. equal to HMD when flowing full

B. decreasing the temperature of water

C. increasing the temperature of water</strong>

D. correct answer is ?

E. only (1)

F. both (1) and (2)

A. nitrogen

B. oxygen

D. hydrogen

A. starch iodide method

B. orthotolidine method

D. none of the above

A. lime treatment

B. by using potassium permanganate

C. chlorination

A. 100 mg/litre

B. 1000 mg/litre

C. 1 mg/litre

A. partially separate system

C. separate system

D. partially combined system

B. 100 to 150

C. 1400 to 1500

D. 500 to 600

B. 15 cm and 100 cm

C. 30 cm and 450 cm

D. 60 cm and 300cm