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

If the diameter of sewer is 225 mm, the gradient required for generating self cleansing velocity, is:


Options are :

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

Answer :1 in 120

The sewage is pumped up:


Options are :

  • From low lying areas
  • All the above
  • From basements
  • Across a high ridge
  • From flat areas

Answer :All the above

Aerobic bacterias:


Options are :

  • Oxidise organic matter in sewage
  • All the above
  • Flourish in the presence of free oxygen
  • Consume organic matter as their food

Answer :All the above

Assertion (A) : Discharging the effluents from the oxidation ponds just up stream of lakes or reservoirs is undesirable

Reason (R) : The discharged algae get settled in the reservoirs and cause anaerobic decomposition and other water qualities


Options are :

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

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

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

During preliminary treatment of a sewage:


Options are :

  • All the above
  • Girt and sand are removed by girt chambers
  • Floating materials are removed by screening
  • Oil and grease are removed from skimming tanks

Answer :All the above

The digested sludge from septic tanks, is removed after a maximum period of:


Options are :

  • 3 years
  • 3.5 years
  • 4 years
  • 5 years

Answer :3 years

The ratio of minimum hourly flow to the average flow of sewage is:


Options are :

  • 1/3
  • 1/2
  • 3/4
  • 1/4

Answer :1/3

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

House connections to the laterals is generally made by:


Options are :

  • R.C.C.
  • Cast iron
  • Glazed stonewares
  • P.C.C.

Answer :Glazed stonewares

Removal of oil and grease from sewage, is known:


Options are :

  • Screening
  • Filtration
  • Skimming
  • None of these

Answer :Skimming

For having central angle ?, the area of cross-section of sewers running partially full, is:


A.


B.


C.


D.


Options are :

  • A
  • D
  • B
  • C

Answer :B

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

Faculative bacterias survive in:


Options are :

  • The presence of oxygen
  • None of these
  • The absence of oxygen

Answer :The presence of oxygen The absence of oxygen

Pick up the incorrect statement from the following:


Options are :

  • The mixture of water and waste products, is called sewage
  • The old convergency system was definitely better than water carried sewerage system
  • The treated sewage effluents, are generally used for irrigating the crops
  • None of these
  • The process of collecting, treating and disposing off the sewage, is called sewerage

Answer :The old convergency system was definitely better than water carried sewerage system

If the flame of a miner's safety lamp in a manhole extinguishes within 5 minutes, the sewer certainly contains:


Options are :

  • None of these
  • Carbon dioxide
  • Methane
  • Oxygen
  • Hydrogen sulphide

Answer :Carbon dioxide

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

Bottom openings 15 cm x 15 cm in the standing baffle wall are provided:


Options are :

  • 15 cm c/c
  • 30 cm c/c
  • 50 cm c/c
  • 22.5 cm c/c

Answer :22.5 cm c/c

The ratio of maximum sewage flow to average sewage flow for trunk mains having diameters more than 1.25 m, is:


Options are :

  • 4.0
  • 2.0
  • 1.5
  • 3.0

Answer :1.5

The asbestos cement sewers are:


Options are :

  • Susceptible to corrosion by sulphuric acid
  • Not structurally strong to bear large compressive stress
  • All the above
  • Light in weight

Answer :All the above

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

The sewer which collects the discharge from a collecting system and delivers it to a treatment plant, is known:


Options are :

  • Lateral sewer
  • Branch sewer
  • House sewer
  • Sewer outfall

Answer :Sewer outfall

The normal values of over flow rates for secondary sedimentation tanks, ranges between:


Options are :

  • 50, 000 to 60, 000 litres/sqm/day
  • 25, 000 to 35, 000 litres/sqm/day
  • None of these
  • 40, 000 to 50, 000 litres/sqm/day
  • 80, 000 to 10, 000 litres/sqm/day

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

Which of the following pumps in used to pump sewage solids with liquid sewage without clogging the pump is:


Options are :

  • None of these
  • Centrifugal pump
  • Reciprocating pump
  • Pneumatic ejector

Answer :Centrifugal pump

Waste Water Engineering MCQ Practice Questions (Civil Eng) Set 4

The pressure exerted by:


Options are :

  • All the above
  • The sewage when running full from inside, is called internal pressure
  • Pressure sewers are designed to be safe in tension
  • The internal pressure if any, causes tensile stress in the pipe material

Answer :All the above

Setting out the alignments of sewers may start from:


Options are :

  • City
  • Out-fall
  • Tail end
  • Any point

Answer :Tail end

A cylindrical ejector having its height 2 m fills after every 10 minutes with a peak sewage discharge of 0.0157 cumec. The diameter of the ejector chamber, is:


Options are :

  • 2.40 m
  • 2.50 m
  • 2.45 m
  • 2.30 m

Answer :2.45 m

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

Pick up the correct statement from the following:


Options are :

  • All the above
  • 90% of digestion takes place in 30 days at 29C, the optimum mesophilic temperature
  • Rate of digestion of slugde is more at higher temperature
  • Mesophilic organisms digest the sludge if the temperature is between 25 and 40C
  • Thermophilic organisms digest the sludge if the temperature ranges from 40 to 60C

Answer :All the above

The Brake Horse power of the motor (efficiency 60%) required for a pump of capacity 0.075 cumec for a total lift of 12 m, is:


Options are :

  • 10
  • 15
  • 20
  • 25

Answer :20

In normal conditions, the period for sludge digestion, is:


Options are :

  • 30 days
  • 10 days
  • 60 days
  • 90 days
  • 20 days

Answer :30 days

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

No treatment of the sewage is given if dilution factor is:


Options are :

  • Between 400 to 500
  • Less than 150
  • Between 200 to 300
  • More than 500
  • Between 150 to 200

Answer :More than 500

For drainage pipes in buildings the test applied before putting them to use, is:


Options are :

  • All the above
  • Smoke test
  • Water test
  • Straightness test

Answer :Smoke test

For sewers, inverted siphon is provided for:


Options are :

  • Four pipes
  • Three pipes
  • One pipe
  • Two pipes

Answer :Three pipes

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

The sewer pipes:


Options are :

  • Should resist the wear and tear caused due to abrasion
  • Are designed for generating self-cleansing velocities at different discharge
  • Carry sewage as gravity conduits
  • All the above

Answer :All the above

Fresh sewage is generally:


Options are :

  • Acidic
  • A source of objectionable odour
  • Alkaline
  • Highly decomposed

Answer :Alkaline

Comment / Suggestion Section
Point our Mistakes and Post Your Suggestions