Waste Water Engineering MCQ

Test your knowledge with important Waste Water Engineering MCQ and their applications. These MCQs are beneficial for competitive exams too. Explore 30 + more Waste Water Engineering MCQs at Bissoy

• The sewer which received discharge from two or more main sewers, is known as
  ক

  A trunk sewer

  খ

  An outfall sewer

  গ

  A main sewer

  ঘ

  An intercepting sewer
• The laying of sewers is done with
  ক

  Magnetic compass

  খ

  Theodolite

  গ

  Level

  ঘ

  Clinometer
• The gradient of sewers depends upon
  ক

  Velocity of flow

  খ

  Diameter of the sewer

  গ

  Discharge

  ঘ

  All the above
• Ventilating shafts are provided to a sewer line at every
  ক

  100 m

  খ

  150 m

  গ

  200 m

  ঘ

  300 m
• Bottom openings 15 cm × 15 cm in the standing baffle wall are provided
  ক

  15 cm c/c

  খ

  22.5 cm c/c

  গ

  30 cm c/c

  ঘ

  50 cm c/c
• The dimensions of a rectangular settling tank are: length 24 m, width 6 m and depth 3 m. If 2 hour detention period for tanks is recommended, the rate of flow of sewage per hour, is
  ক

  204 cu.m

  খ

  208 cu.m

  গ

  212 cu.m

  ঘ

  216 cu.m
• The sewage is pumped up
  ক

  From low lying areas

  খ

  From flat areas

  গ

  From basements

  ঘ

  All the above
• Fresh sewage is generally
  ক

  Alkaline

  খ

  Acidic

  গ

  Highly decomposed

  ঘ

  A source of objectionable odour
• The average temperature of sewage in India, is
  ক

  10°C

  খ

  15°C

  গ

  20°C

  ঘ

  25°C
• For detecting the nitrites in the sewage, the matching colour may be developed by adding
  ক

  Potassium permanganate

  খ

  Sulphuric acid and napthamine

  গ

  Phenol-di -sulphuric acid potassium hydroxide

  ঘ

  None of these
• For detecting the nitrates in sewage, the colour may be developed by adding
  ক

  Potassium permanganate

  খ

  Sulphuric acid and napthamine

  গ

  Phenol-di -sulphuric acid and potassium hydroxide

  ঘ

  None of these
• The algae dies out in the zone of
  ক

  Degradation

  খ

  Active decomposition

  গ

  Recovery

  ঘ

  Cleaner water
• Imhoff cone is used to determine
  ক

  Settleable solids

  খ

  Suspended solids

  গ

  Dissolved solids

  ঘ

  None of these
• The most effective arrangement for diverting excess storm water into a natural drainage, is
  ক

  Leaping weir

  খ

  Overflow weir

  গ

  Siphon spill way

  ঘ

  None of these
• At the junction of sewers
  ক

  Top of smaller sewer is kept lower

  খ

  Top of larger sewer is kept lower

  গ

  Tops of both the sewers are at the same level

  ঘ

  None of these
• The design period in years for pumping plants, is
  ক

  1

  খ

  2 to 3

  গ

  3 to 5

  ঘ

  5 to 10
• The moisture content of sludge is reduced from 90% to 80% in a sludge digestion tank. The percentage decrease in the volume of sludge, is
  ক

  25 %

  খ

  50 %

  গ

  10 %

  ঘ

  5 %
• The most dangerous pollutant in vehicular emissions is
  ক

  CO₂

  খ

  SO₂

  গ

  CO₂

  ঘ

  O₂
• If the pH value of sewage is 7
  ক

  It is acidic

  খ

  It is alkaline

  গ

  It is neutral

  ঘ

  None of these
• In sewers the highest non-scouring velocity is achieved in
  ক

  Glazed bricks sewers

  খ

  Cast iron sewers

  গ

  Cement concrete sewers

  ঘ

  Stone ware sewers
• In sewage having fully oxidised organic matter, the nitrogen exists in the form of
  ক

  Nitrites

  খ

  Nitrates

  গ

  Free ammonia

  ঘ

  Aluminoid nitrogen
• Traps
  ক

  Are water seals which prevent the entry of foul gases

  খ

  Are used to trap the rats entering sewers

  গ

  Dissolve the foul gases

  ঘ

  Create symphonic action to increase the quick disposal of sewerage
• Boussinesq’s equation for ascertaining unit pressure at a depth on sewers due to traffic loads, is
  ক

  $${{\text{p}}_{\text{t}}} = \frac{{3{{\text{H}}^3}{\text{p}}}}{{2\pi {{\text{Z}}^5}}}$$

  খ

  $${{\text{p}}_{\text{t}}} = \frac{{2{{\text{H}}^3}{\text{p}}}}{{3\pi {{\text{Z}}^5}}}$$

  গ

  $${{\text{p}}_{\text{t}}} = \frac{{{\text{3}}{{\text{H}}^3}{\text{p}}}}{{2{{\text{Z}}^5}}}$$

  ঘ

  $${{\text{p}}_{\text{t}}} = \frac{{{\text{2}}\pi {{\text{H}}^3}{\text{p}}}}{{3\pi {{\text{Z}}^5}}}$$

  ঙ

  None of these
• During preliminary treatment of a sewage
  ক

  Oil and grease are removed from skimming tanks

  খ

  Floating materials are removed by screening

  গ

  Girt and sand are removed by girt chambers

  ঘ

  All the above
• Aerobic activity is maximum
  ক

  In freshly produced sewage

  খ

  At sewer pipes

  গ

  In sewer treatment plants

  ঘ

  None of these
• Which one of the following tests is used for testing sewer pipes?
  ক

  Water test

  খ

  Ball test

  গ

  Mirror test

  ঘ

  All of these
• The detention time (t) of a settling tank, may be defined as the time required for
  ক

  A particle to travel along its length

  খ

  A particle to travel from top surface to bottom sludge zone

  গ

  The flow of sewage to fill the tank

  ঘ

  None of these
• The sewer pipes
  ক

  Carry sewage as gravity conduits

  খ

  Are designed for generating self-cleansing velocities at different discharge

  গ

  Should resist the wear and tear caused due to abrasion

  ঘ

  All the above
• The reduced levels of the string at the consecutive sight rails A and B are 203.575 m, 203.475 m respectively. If the difference of their R.D.s is 10 m, the gradient of the sewer line is
  ক

  1 in 100 upward

  খ

  1 in 500 upward

  গ

  1 in 100 downward

  ঘ

  1 in 503 upward
• If the length of overland flow from the critical point to the mouth of drain is 13.58 km and difference in level between the critical point and drain mouth is 10 m, the inlet time is
  ক

  2 hours

  খ

  4 hours

  গ

  6 hours

  ঘ

  8 hours