Waste Water Engineering MCQ Practice Questions (Civil Eng) Set 5

The sewers:


A.

Must be of adequate size to avoid over flow


B.

Must flow under gravity

to full


C.

Must be laid at least 2 to 3 m deep to collect /water from the basements


D.

All the above


Options are :

  • B
  • A
  • D
  • C

Answer :D

For drains up to 15 cumecs, the depth d and width B are related by:


Options are :

  • d = 0.2 ?B
  • B = 0.2 ?d
  • d = 0.5 ?B
  • B = ?0.5 d

Answer :d = 0.5 ?B

Waste Water Engineering MCQ Practice Questions (Civil Eng) Set 6

In the activated sludge process:


Options are :

  • Aeration is done with an admixture of previously aerated sludge
  • Sludge is activated by constant stirring
  • Water is removed by centrifugal action
  • Aeration is continued till stability

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

The value of Chezy's constant is used in:



Options are :

  • Chezy's formula
  • Bazin's formula
  • Manning's formula
  • Kutter's

Answer :Kutter's

Aerobic activity is maximum:


Options are :

  • In sewer treatment plants
  • At sewer pipes
  • In freshly produced sewage
  • None of these

Answer :In freshly produced sewage

Waste Water Engineering MCQ Practice Questions (Civil Eng) Set 7

If the diameter of a sewer is 100 mm, the gradient required for generating self cleansing velocity, is:


Options are :

  • 1 in 60
  • None of these
  • 1 in 100
  • 1 in 120

Answer :1 in 60

For detecting the nitrites in the sewage, the matching colour may be developed by adding:


Options are :

  • Pottassium permanganate
  • None of these
  • Sulphuric acid and napthamine
  • Phenol-di-sulphuric acid pottassium hydroxide

Answer :Sulphuric acid and napthamine

Boussinesq's equation for ascertaining unit pressure at a depth H on sewers due to traffic loads, is:


A.


B.


C.


D.


E.

None of these


Options are :

  • C
  • D
  • E
  • A
  • B

Answer :A

Waste Water Engineering MCQ Practice Questions (Civil Eng) Set 8

Which one of the following resists hydrogen sulphide corrosion:


Options are :

  • R.C.C.
  • Glazed ware
  • Asbestos cement
  • Glazed stone wares

Answer :Glazed ware

Assertion (A) : The determination of pH value of sewerage is important

Reason (R) : The efficiency of certain treatment methods depends upon the availability of pH value


Options are :

  • A is false but R is true
  • A is true but R is false
  • Both A and R are true but R is not a correct explanation of A
  • Both A and R are true and R is the correct explanation of A

Answer :Both A and R are true and R is the correct explanation of A

The settlement of a particle in sedimentation tank, is affected by:


Options are :

  • Viscosity of water
  • All the above
  • Velocity of flow
  • Specific gravity of solid
  • Size and shape of solid

Answer :All the above

Waste Water Engineering MCQ Practice Questions (Civil Eng) Set 9

The sewage treatment in septic tanks is due to:


Options are :

  • Anaerobic decomposition
  • None of these
  • Aerobic decomposition
  • Parasitic decomposition

Answer :Anaerobic decomposition

The ratio of design discharge to the surface area of a sedimentation tank is called:


Options are :

  • Surface loading
  • Overflow velocity
  • All of these
  • Overflow rate

Answer :All of these

The minimum diameter of a sewer is kept:


Options are :

  • 25 cm
  • 10 cm
  • 30 cm
  • 20 cm
  • 15 cm

Answer :15 cm

In 1000 kg of sewage, the total solids approximate:


Options are :

  • 5 kg to 7.5 kg
  • 1 kg to 2.0 kg
  • 0.5 to 1.0 kg
  • 7.5 kg to 10 kg

Answer :0.5 to 1.0 kg

Hume steel pipes are:


Options are :

  • Steel pipes
  • Steel shell coated from inside with cement mortar
  • Steel shell coated from outside with cement mortar
  • R.C.C. pipes
  • None of these

Answer :Steel shell coated from inside with cement mortar Steel shell coated from outside with cement mortar

Stone ware pipes are:


Options are :

  • Hydraulically efficient because of their smooth interior surface
  • Specially suited to pressure pipes
  • Highly impervious
  • None of these
  • Highly resistant to sulphide corrosion

Answer :Specially suited to pressure pipes

Waste Water Engineering MCQ Practice Questions (Civil Eng) Set 1

Pick up the correct statement from the following:


Options are :

  • Anaerobic bacteria flourish in the absence of oxygen
  • All the above
  • Aerobic bacteria flourish in the presence of oxygen
  • Facultative bacteria flourish with or without oxygen

Answer :All the above

Oxidation process results in the formation of:


Options are :

  • Carbon dioxide
  • All the above
  • Sulphates
  • Nitrates

Answer :All the above

The minimum diameter of sewer to be adopted is:


Options are :

  • 25 cm
  • 15 cm
  • 12.5 cm
  • 10 cm

Answer :15 cm

Waste Water Engineering MCQ Practice Questions (Civil Eng) Set 10

To test chemical oxygen demand (C.O.D.) of sewage, organic matter is oxidised by pottassium dichromate in the presence of:


Options are :

  • Nitric acid
  • Citric acid
  • Hydrochloric acid
  • Sulphuric acid

Answer :Sulphuric acid

D is the diameter of a circular sewer and ? is the side of a square section sewer. If both are hydraulically equivalent, the relationship which holds good, is:


Options are :

  • ?D^(3/2) = 4 b^(3/2)
  • ?D^(2/3) = 4 b^(2/3)
  • None of these
  • ?D^(3/8) = 4 b^(3/8)
  • ?D^(8/3) = 4 b^(8/3)

Answer :?D^(8/3) = 4 b^(8/3)

The laying of sewers is done with:


Options are :

  • Level
  • Plane table
  • Theodolite
  • Clinometer
  • Magnetic compass

Answer :Level

Waste Water Engineering MCQ Practice Questions (Civil Eng) Set 11

As compared to fresh river water, sea water contains oxygen:


Options are :

  • 10% less
  • 20% less
  • 10% more
  • 20% more

Answer :20% less

Sewer manholes are generally provided at:


Options are :

  • All of these
  • The change of direction
  • The change of gradient
  • The junctions of sewers

Answer :All of these

Pathogens (or pathogentic bacterias) in water may cause:


Options are :

  • All the above
  • Infectious hepatitis
  • Cholera
  • Typhoid
  • Dysentery

Answer :All the above

Waste Water Engineering MCQ Practice Questions (Civil Eng) Set 2

Sewer pipes need be checked for:


Options are :

  • Maximum flow
  • Minimum flow
  • None of these

Answer :Maximum flow Minimum flow

Antisyphonage pipe is fitted:


Options are :

  • On manholes
  • At the beginning of sewer line
  • With a W.C. trap
  • At the end of septic tanks

Answer :With a W.C. trap

In a sludge digestion tank if the moisture content of sludge V1 litres is reduced from p1 % to p2 % the volume V2 is:


A.


B.


C.


D.


Options are :

  • D
  • A
  • B
  • C

Answer :C

Waste Water Engineering MCQ Practice Questions (Civil Eng) Set 3

The settlement velocity of a solid (diameter 0.5 mm, specific gravity 1.75) in water having temperature 10C, is:


Options are :

  • 213.5 cm/sec
  • 413.5 cm/sec
  • 313.5 cm/sec
  • 500 cm/sec

Answer :313.5 cm/sec

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