Waste Water Engineering MCQs

Option A: Near the inner surface of the pipe

Option B: Near the outer surface of the pipe

Option C: Both A. and B.

Option D: With elliptical cage

Correct Answer: With elliptical cage ✔

Option A: 1.5

Option B: 2.0

Option C: 3.0

Option D: 4.0

Correct Answer: 1.5 ✔

Option A: Cast iron sewers

Option B: Cement concrete sewers

Option C: Glazed bricks sewers

Option D: Stone ware sewers

Correct Answer: Glazed bricks sewers ✔

Option A: 5 m

Option B: 5.5 m

Option C: 6.5 m

Option D: 7 m

Correct Answer: 7 m ✔

Option A: 25,000 to 35,000 litres/sqm/day

Option B: 40,000 to 50,000 litres/sqm/day

Option C: 50,000 to 60,000 litres/sqm/day

Option D: 80,000 to 10,000 litres/sqm/day

Correct Answer: 25,000 to 35,000 litres/sqm/day ✔

Option A: It is acidic

Option B: It is alkaline

Option C: It is neutral

Option D: None of these

Correct Answer: It is neutral ✔

Option A: 1.5

Option B: 2.0

Option C: 2.5

Option D: 3.0

Correct Answer: 1.5 ✔

Option A: pt = 3H3p/2 Z5

Option B: pt = 2H3p/3 Z5

Option C: pt = 3H3p/2Z5

Option D: pt = 2 3p/3Z5

Correct Answer: pt = 3H3p/2 Z5 ✔

Option A: 100 m

Option B: 150 m

Option C: 200 m

Option D: 300 m

Correct Answer: 300 m ✔

Option A: Tensile force

Option B: Compressive force

Option C: Bending force

Option D: Shearing force

Correct Answer: Compressive force ✔

Option A: 20 m

Option B: 30 m

Option C: 45 m

Option D: 75 m

Correct Answer: 45 m ✔

Option A: The presence of oxygen

Option B: The absence of oxygen

Option C: Both cases A. and B.

Option D: Neither A. nor B.

Correct Answer: C. Both cases A. and B. ✔

Option A: 1.0 m

Option B: 2.0 m

Option C: 3.0 m

Option D: 4.0 m

Correct Answer: 3.0 m ✔

Option A: Chezy’s formula

Option B: Bazin’s formula

Option C: Kutter’s formula

Option D: Manning’s formula

Correct Answer: Manning’s formula ✔

Option A: Acid fermentation

Option B: Acid regressio

Option C: Alkaline fermentation

Option D: None of these

Correct Answer: Acid fermentation ✔

Option A: 2 metres/sec

Option B: 1 metre/sec

Option C: 0.5 metre/sec

Option D: 0.25 metre/sec

Correct Answer: 2 metres/sec ✔

Option A: Nitrites are formed

Option B: Nitrates are formed

Option C: Carbondioxide is formed

Option D: Ammonia is formed

Correct Answer: Ammonia is formed ✔

Option A: Branch sewers

Option B: Main sewers

Option C: Trunk sewers

Option D: All the above

Correct Answer: All the above ✔

Option A: Centrifugal pump

Option B: Reciprocating pump

Option C: Pneumatic ejector

Option D: None of these

Correct Answer: Centrifugal pump ✔

Option A: 1

Option B: 2 to 3

Option C: 3 to 5

Option D: 5 to 10

Correct Answer: 1 ✔

Option A: Bend

Option B: Junction

Option C: Change of gradient

Option D: All the above

Correct Answer: All the above ✔

Option A: 100

Option B: 60

Option C: 40

Option D: 20

Correct Answer: 20 ✔

Option A: 1045 mm

Option B: 1065 mm

Option C: 1075 mm

Option D: 1095 mm

Correct Answer: 1095 mm ✔

Option A: Flow velocity is kept 0.09 m/sec

Option B: Detention period is kept 3 to 4 minutes

Option C: Organic and inorganic materials are separated

Option D: All the above

Correct Answer: All the above ✔

Option A: Perpendicular to the direction of flow

Option B: Parallel to the direction of flow

Option C: At an angle 30° to 60° to the direction of flow

Option D: None of these

Correct Answer: At an angle 30° to 60° to the direction of flow ✔

Option A: Typhoid

Option B: Cholera

Option C: Dysentery

Option D: All the above

Correct Answer: All the above ✔

Option A: Chezy’s formula

Option B: Bazin’s formula

Option C: Kutter’s formula

Option D: Manning’s formula

Correct Answer: Bazin’s formula ✔

Option A: 50 m

Option B: 100 m

Option C: 200 m

Option D: 300 m

Correct Answer: 300 m ✔

Option A: Septic tanks are horizontal continuous flow type of sedimentation tanks

Option B: Septic tanks are generally provided a detention period of 12 to 36 hours

Option C: Septic tanks are completely covered and high vent shafts are provided for the escape of foul gases

Option D: None of these

Correct Answer: None of these ✔

Option A: One pipe

Option B: Two pipes

Option C: Three pipes

Option D: Four pipes

Correct Answer: Three pipes ✔

Option A: Carbondioxide

Option B: Oxygen

Option C: Nitrogen

Option D: Sulphur-dioxide

Correct Answer: Sulphur-dioxide ✔

Option A: 2.30 m

Option B: 2.40 m

Option C: 2.45 m

Option D: 2.50 m

Correct Answer: 2.45 m ✔

Option A: Lung cancer

Option B: Skin cancer

Option C: Bronchitis

Option D: Heart disorder

Correct Answer: Skin cancer ✔

Option A: Sanitary sewage

Option B: Industrial waste

Option C: Storm sewage

Option D: None of these

Correct Answer: Storm sewage ✔

Option A: The larger the sewer in size, more will be velocity

Option B: The smaller the sewer in size, less will be velocity

Option C: The larger the sewer in size, no deposition will take place

Option D: The larger the sewer in size, deposition will take place

Correct Answer: The larger the sewer in size, deposition will take place ✔

Option A: 100

Option B: 1000

Option C: 5000

Option D: 10000

Correct Answer: 100 ✔

Option A: 0.9 cm

Option B: 1.2 m

Option C: 1.5 m

Option D: > 1.5 m

Correct Answer: 1.5 m ✔

Option A: In treated sewage, 4 ppm of D.O. is essential

Option B: Only very fresh sewage contains some dissolved oxygen

Option C: The solubility of oxygen in sewage is 95% that is in distilled water

Option D: All the above

Correct Answer: All the above ✔

Option A: Stone ware pipes

Option B: Earthenware pipes

Option C: C.I. pipes

Option D: G.I. pipes

Correct Answer: Earthenware pipes ✔

Option A: 50 ppm

Option B: 100 ppm

Option C: 150 ppm

Option D: 200 ppm

Correct Answer: 200 ppm ✔

Option A: Equal to 7

Option B: More than 7

Option C: Less than 7

Option D: Equal to zero

Correct Answer: More than 7 ✔

Option A: The maximum rate of storm runoff is called peak drainage discharge

Option B: Rational method of estimating peak run off, may be used precisely for areas less than 50 hectares

Option C: The period after which the entire area starts contributing to the runoff, is called the time of concentration

Option D: All the above

Correct Answer: All the above ✔

Option A: 20 mm

Option B: 30 mm

Option C: 40 mm

Option D: 50 mm

Correct Answer: 50 mm ✔

Option A: Carry sewage as gravity conduits

Option B: Are designed for generating self-cleansing velocities at different discharge

Option C: Should resist the wear and tear caused due to abrasion

Option D: All the above

Correct Answer: All the above ✔

Option A: 0.05552 cumec

Option B: 0.05554 cumec

Option C: 0.05556 cumec

Option D: 0.0556 cumec

Correct Answer: 0.05556 cumec ✔

Option A: The water supply pipes carry pure water free from solid particles

Option B: The water supply pipes get clogged if flow velocity is less than self cleansing velocity

Option C: The sewers may be carried up and down the hills and valleys

Option D: The sewer pipes are generally laid along level hills

Correct Answer: The water supply pipes carry pure water free from solid particles ✔

Option A: Biological activity of bacteria in sewage

Option B: Solubility of gases in sewage

Option C: Viscosity of sewage

Option D: All the above

Correct Answer: All the above ✔

Option A: Rivers

Option B: Seas

Option C: Lakes

Option D: None of these

Correct Answer: Seas ✔

Option A: Bacterias

Option B: Suspended solids

Option C: Sediments

Option D: Hardness

Correct Answer: Bacterias ✔

Option A: Inverted syphon

Option B: Depressed sewer

Option C: Sag pipe

Option D: all of these

Correct Answer: all of these ✔

Option A: 1.5

Option B: 2.0

Option C: 3.0

Option D: 4.0

Correct Answer: 2.0 ✔

Option A: Flow velocity 0.15 m to 0.3 m/sec is kept

Option B: Depth of 0.9 m to 1.20 m is kept

Option C: One minute of detention period is kept

Option D: All the above

Correct Answer: All the above ✔

Option A: Small sewers are cleaned by flushing

Option B: Medium sewers are cleaned by cane rodding

Option C: Medium sewers may be cleaned by pills

Option D: All the above

Correct Answer: All the above ✔

Option A: Methane gas

Option B: Hydrogen sulphide

Option C: Carbondioxide gas

Option D: Diesel vapours

Correct Answer: Hydrogen sulphide ✔

Option A: City

Option B: Out-fall

Option C: Tail end

Option D: Any point

Correct Answer: Tail end ✔

Option A: Maximum daily flow = 2 times the average daily flow

Option B: Maximum daily flow = average daily flow

Option C: Sewers are designed for minimum permissible velocity at minimum flow

Option D: All the above

Correct Answer: All the above ✔

Option A: Centrifugal pump

Option B: Reciprocating pump

Option C: Pneumatic ejector

Option D: Air pressure pump

Correct Answer: Centrifugal pump ✔

Option A: 2.5 to 3.0 m/sec

Option B: 3.0 to 4.0 m/sec

Option C: 3.5 to 4.5 m/sec

Option D: 4.5 to 5.5 m/sec

Correct Answer: 2.5 to 3.0 m/sec ✔

Option A: Large suspended organic solids

Option B: Oil and grease

Option C: Sand and girt

Option D: Floating materials

Correct Answer: Large suspended organic solids ✔

Option A: 1 in 5

Option B: 1 in 10

Option C: 1 in 15

Option D: 1 in 20

Correct Answer: 1 in 10 ✔

Option A: Thyroid

Option B: Kidneys

Option C: Eyes

Option D: Ovaries/testis

Correct Answer: Ovaries/testis ✔

Option A: cm/minute

Option B: cm/hour

Option C: cm/day

Option D: None of these

Correct Answer: cm/hour ✔

Option A: 25 to 50 m

Option B: 50 m to 100 m

Option C: 100 m to 150 m

Option D: 150 m to 300 m

Correct Answer: 150 m to 300 m ✔

Option A: Vs = 418 (Gs – Gw) d [(3T + 70)/100]

Option B: Vs = 418 (Gs – Gw)d² [(3T + 70)/100]

Option C: Vs = 218 (Gs – Gw)d² [(3T + 70)/100]

Option D: Vs = 218 (Gs – Gw)d [(3T + 70)/100]

Correct Answer: Vs = 418 (Gs – Gw)d² [(3T + 70)/100] ✔

Option A: Aeration is continued till stability

Option B: Aeration is done with an admixture of previously aerated sludge

Option C: Sludge is activated by constant stirring

Option D: Water is removed by centrifugal action

Correct Answer: Aeration is done with an admixture of previously aerated sludge ✔

Option A: d/D = ½ (1 – –

Option B: a/A

Option C: r/R = [1 –

Option D: All the above

Correct Answer: All the above ✔

Option A: 1.39 m

Option B: 1.49 m

Option C: 1.59 m

Option D: 1.69 m

Correct Answer: 1.69 m ✔

Option A: With beds of rocks and gravels

Option B: Lined with stones

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. and B. ✔

Option A: 2 days

Option B: 7 days

Option C: 12 days

Option D: 14 days

Correct Answer: 14 days ✔

Option A: 30 to 40%

Option B: 40 to 60%

Option C: 60 to 80%

Option D: 80 to 90%

Correct Answer: 60 to 80% ✔

Option A: 10 days

Option B: 20 days

Option C: 30 days

Option D: 60 days

Correct Answer: 30 days ✔

Option A: 10 cm

Option B: 15 cm

Option C: 20 cm

Option D: All the above

Correct Answer: All the above ✔

Option A: Oxygen

Option B: Nitrogen

Option C: Hydrogen

Option D: Carbon dioxide

Correct Answer: Carbon dioxide ✔

Option A: Nitrates

Option B: Nitrites

Option C: Free ammonia

Option D: None of these

Correct Answer: Nitrates ✔

Option A: 100 mg/l

Option B: 200 mg/l

Option C: 300 mg/l

Option D: 400 mg/l

Correct Answer: 400 mg/l ✔

Option A: Velocity at dry weather flow

Option B: Velocity of water at flushing

Option C: Velocity at which no accumulation remains in the drains

Option D: Velocity of water in a pressure filter

Correct Answer: Velocity at which no accumulation remains in the drains ✔

Option A: d = 0.2 B

Option B: d = 0.5 B

Option C: B = 0.2 d

Option D: B = 0.5 d

Correct Answer: d = 0.5 B ✔

Option A: 30 litres/person/year

Option B: 25 litres/person/year

Option C: 30 litres/person/month

Option D: 25 litres/person/month

Correct Answer: 30 litres/person/year ✔

Option A: Filtration process is used

Option B: Biological action is used

Option C: Neither A. nor B.

Option D: Both A. and B.

Correct Answer: Biological action is used ✔

Option A: 2 hours

Option B: 4 hours

Option C: 6 hours

Option D: 8 hours

Correct Answer: 8 hours ✔

Option A: Steel pipes

Option B: Steel shell coated from inside with cement mortar

Option C: Steel shell coated from outside with cement mortar

Option D: Both B. and C.

Correct Answer: D. Both B. and C. ✔

Option A: 4 to 8 hours

Option B: 8 to 16 hours

Option C: 16 to 24 hours

Option D: 24 to 36 hours

Correct Answer: 4 to 8 hours ✔

Option A: 100 cm

Option B: 90 cm

Option C: 80 cm

Option D: 50 cm

Correct Answer: 100 cm ✔

Option A: Used to remove the grease and oil

Option B: Those from which sludge is skimmed out

Option C: Tanks provided with self- cleansing screens

Option D: Improved version of grit chambers

Correct Answer: Used to remove the grease and oil ✔

Option A: Bazin

Option B: Crimp and Bruges

Option C: William-Hazen

Option D: Kutter

Correct Answer: Crimp and Bruges ✔

Option A: Brick sewer

Option B: Cast iron sewer

Option C: R.C.C. sewer

Option D: Lead sewer

Correct Answer: Lead sewer ✔

Option A: Rate of digestion of sludge is more at higher temperature

Option B: Thermophilic organisms digest the sludge if the temperature ranges from 40° to 60°C

Option C: Mesophilic organisms digest the sludge if the temperature is between 25° and 40°C

Option D: All the above

Correct Answer: All the above ✔

Option A: Its intensity

Option B: Its direction

Option C: Its frequency

Option D: All the above

Correct Answer: All the above ✔

Option A: Hydrogen sulphide gas in excess, may cause corrosion of concrete sewers

Option B: 4 ppm of Dissolved Oxygen (D.O.) is ensured before discharging the treated sewage in river

Option C: Solubility of oxygen in sewage is 95% of that of distilled water

Option D: All the above

Correct Answer: All the above ✔

Option A: Bath rooms

Option B: Wash basins

Option C: Kitchen sinks

Option D: Toilets

Correct Answer: Toilets ✔

Option A: Running expenses

Option B: Maintenance expenses

Option C: Operation expenses

Option D: All the above

Correct Answer: All the above ✔

Option A: 0.112 kg in suspension

Option B: 0.112 kg in solution

Option C: 0.225 kg in solution

Option D: Both A. and C. of above

Correct Answer: D. Both A. and C. of above ✔

Option A: A sedimentation tank and an activated sludge treatment plant

Option B: A plant consisting of Imhoff tanks with low rate trickling filters

Option C: Sedimentation tanks with high rate trickling filters

Option D: None of these

Correct Answer: A sedimentation tank and an activated sludge treatment plant ✔

Option A: A trunk sewer

Option B: An outfall sewer

Option C: A main sewer

Option D: An intercepting sewer

Correct Answer: A trunk sewer ✔

Option A: Mean radius of sewer

Option B: Difference in heads between two points in circular pipes

Option C: Mean of radii in a pipe line of varying cross -sections

Option D: Cross-sectional area/wetted perimeter

Correct Answer: Cross-sectional area/wetted perimeter ✔

Option A: Are water seals which prevent the entry of foul gases

Option B: Are used to trap the rats entering sewers

Option C: Dissolve the foul gases

Option D: Create symphonic action to increase the quick disposal of sewerage

Correct Answer: Are water seals which prevent the entry of foul gases ✔

Option A: Flourish in the presence of free oxygen

Option B: Consume organic matter as their food

Option C: Oxidise organic matter in sewage

Option D: All the above

Correct Answer: All the above ✔

Option A: Low estimates of the average and maximum flows

Option B: Large scale infiltration of storm water

Option C: Unexpected increase in population

Option D: All the above

Correct Answer: All the above ✔

Option A: Average daily rate of flow

Option B: Average monthly rate of flow

Option C: Average annual rate of flow

Option D: Water supply allowance per capita

Correct Answer: Water supply allowance per capita ✔

Option A: Fruhling

Option B: Lloyd David

Option C: Kuichling

Option D: All of these

Correct Answer: All of these ✔