Explore topic-wise MCQs in Environmental Engineering.

This section includes 180 Mcqs, each offering curated multiple-choice questions to sharpen your Environmental Engineering knowledge and support exam preparation. Choose a topic below to get started.

51.

What is the color of the surface coating formed during the filtration process?

A. White
B. Brown
C. Green
D. Reddish brown
Answer» E.
52.

The under drainage system in pressure consists of __________

A. Central drains connected to lateral drain
B. Wheeler system
C. Wagner system
D. Pipe grids, false bottom
Answer» E.
53.

In the ________ zone of purification in filter media, bacteria oxidizes the organic matter completely.

A. Autotrophic
B. Heterotrophic
C. Schmutzdecke
D. Electrolytic
Answer» C. Schmutzdecke
54.

Which device solved the problem of unstable hydraulic conditions and operation of sludge removal equipment?

A. Centrifugal pump
B. Pulsator clarifier
C. Tube settler
D. Flocculator
Answer» D. Flocculator
55.

The size of Anthracite used in dual media filter is __________

A. 1-2mm
B. 1.25-2.5mm
C. 3-4mm
D. 4-5mm
Answer» C. 3-4mm
56.

Which material is provided for the up flow bed in dual media bi-flow filter?

A. Anthracite
B. Sand
C. Rice husk
D. Graphite
Answer» C. Rice husk
57.

What is the value of the uniformity coefficient in a rapid sand filter?

A. 1
B. 1.5
C. 2
D. 2.5
Answer» C. 2
58.

The thickness of the suspended matter on top of the sand bed is __________

A. Directly proportional to head loss
B. Inversely proportional to head loss
C. Independent of the head loss
D. Directly proportional to the square of head loss
Answer» B. Inversely proportional to head loss
59.

When the impurities are separated by the gravitation of settling particles, the operation is called ______

A. Sedimentation with coagulant
B. Plain sedimentation
C. Secondary sedimentation
D. Disinfection
Answer» C. Secondary sedimentation
60.

The depth of an enclosed tank of a rapid sand filter lies in the range of ______

A. 1-2m
B. 2.5-3.5m
C. 2-5m
D. 3-5m
Answer» C. 2-5m
61.

The head loss through the bed of solids of the filter can be determined by __________

A. Carmen-Kozney equation
B. Rose equation
C. Carmen-Kozney and Rose equation
D. Charles equation
Answer» D. Charles equation
62.

In mixed media filter, the filtration is done from ______

A. Fine to finer
B. Coarse to coarser
C. Fine to coarse
D. Coarse to fine
Answer» E.
63.

How the performance of the rapid sand filter can be improved?

A. Replacing the top 15 cm layer of sand with Anthracite
B. Replacing the bottom15 cm layer of sand with Anthracite
C. Increasing the thickness of a layer of sand
D. Replacing 15 cm layer of Anthracite with sand
Answer» B. Replacing the bottom15 cm layer of sand with Anthracite
64.

The slow sand filter is efficient in removing turbidity of water.

A. True
B. False
C. May be True or False
D. Can't say
Answer» C. May be True or False
65.

In which type of filter, the filtration is done in two opposite directions at the same time?

A. Dual media filter
B. Mixed media filter
C. Bi-flow filter
D. Rapid sand filter
Answer» D. Rapid sand filter
66.

Which material is provided for the down-flow bed in dual media bi-flow filter?

A. Coal sand
B. Garnet sand
C. Rice husk
D. Graphite
Answer» B. Garnet sand
67.

The effective size of a rapid sand filter is ______

A. 0.45mm
B. 0.7mm
C. 0.8mm
D. 0.9mm
Answer» B. 0.7mm
68.

The turbidity of water applied to rapid sand filter is less than _______

A. 35-40ppm
B. 10-20ppm
C. 30-40ppm
D. 10-15ppm
Answer» B. 10-20ppm
69.

Consider the following statement.i. The slow sand filter is not efficient in removing turbidityii. The slow sand filter has a high initial costiii. Skilled supervision is required in slow sand filterWhich of the above statement is/are correct?

A. Only iii
B. i, ii
C. i, ii, iii
D. ii, iii
Answer» C. i, ii, iii
70.

What is the size of sand used in a dual media filter?

A. 0.5-1mm
B. 1-2mm
C. 2-3mm
D. 3.5-4mm
Answer» B. 1-2mm
71.

What is the thickness of a layer of a diatomite filter?

A. 1mm
B. 2mm
C. 3mm
D. 4mm
Answer» D. 4mm
72.

Which of the following order is correct regarding the specific gravity of the materials used in the mixed media filter?

A. Anthracite coal < Sand > Garnet sand
B. Anthracite coal > Sand > Garnet sand
C. Anthracite coal = Sand = Garnet sand
D. Anthracite coal < Sand < Garnet sand
Answer» E.
73.

How is the grain size distribution of sand in rapid sand filter?

A. Stratified
B. Unlayered
C. Layered with heaviest grains at the top
D. Layered with lightest grains at the top
Answer» E.
74.

In which type of filter, rate of filtration is low?

A. Slow sand filter
B. Rapid sand filter
C. Gravity filter
D. Pressure filter
Answer» B. Rapid sand filter
75.

When the fineness of sand increases __________

A. The bacterial efficiency increases
B. The rate of filtration increases
C. The rate of filtration first decrease, then increase
D. The bacterial efficiency remains constant
Answer» B. The rate of filtration increases
76.

What is the range of pressure in pressure filter?

A. 1-5 kg/cm²
B. 2-5 kg/cm²
C. 3-7 kg/cm²
D. 1-8 kg/cm²
Answer» D. 1-8 kg/cm²
77.

Which of the following has the highest shape factor as stated by Carmen?

A. Ottawa sand
B. Pulverized coal
C. Rounded coal
D. Angular sand
Answer» B. Pulverized coal
78.

Which of the following is the best filter in terms of rate of filtration?

A. Pressure filter
B. Rapid sand filter
C. Dual media filter
D. Mixed media filter
Answer» E.
79.

The loss of head during cleaning operation of a rapid sand filter is __________

A. 15-30cm
B. 1-5cm
C. 10-20cm
D. 10-25cm
Answer» B. 1-5cm
80.

Consider the following statement.i. Slow sand filter is not flexible in variation in demandii. The rapid sand filter is flexible in fluctuations in demandiii. The method of cleaning of a slow sand filter involves agitation and back-washingWhich of the above statement is/are correct?

A. i, ii
B. i, ii, iii
C. ii, iii
D. Only iii
Answer» B. i, ii, iii
81.

In which type of under drainage system of rapid sand filter, laterals are provided with strainers?

A. Perforated pipe system
B. Pipe and strainer system
C. Wheeler system
D. Wagner system
Answer» C. Wheeler system
82.

Which of the following is the expression of the Rose equation where symbols have their usual meanings?

A. hf = f* (L/(s *d)) * ((1-e) /e³) * (v²/g)
B. hf = f* (L/(s *d)) * ((1-e) /e³) * (v/g)
C. hf = f* (L/(s *d)) * ((1-e) /e⁴) * (v²/g)
D. hf = f* (L/(s *d)) * ((1-e) /e²) * (v²/g)
Answer» B. hf = f* (L/(s *d)) * ((1-e) /e³) * (v/g)
83.

Which type of filter is used in treating swimming pool water?

A. Slow sand filter
B. Rapid sand filter
C. Dual media filter
D. Pressure filter
Answer» E.
84.

The test for finding the optimum coagulant dose in water is ____________

A. Chromatography
B. Jar test
C. Kjeldahl test
D. Dilatancy test
Answer» C. Kjeldahl test
85.

The uniformity characteristics of sand expressed in terms of __________

A. Effective size
B. Effective size and uniformity coefficient
C. Uniformity coefficient
D. Mean velocity
Answer» C. Uniformity coefficient
86.

What is the maximum filter head up to which slow sand filters are worked upon?

A. 25cm
B. 50cm
C. 75cm
D. 100cm
Answer» D. 100cm
87.

Which is the first zone of purification in a sand bed?

A. Autotrophic zone
B. Heterotrophic zone
C. Schmutzdecke zone
D. Electrolytic zone
Answer» D. Electrolytic zone
88.

What is the specific gravity of Anthracite used in a dual media filter?

A. 1
B. 1.4
C. 2.4
D. 4.2
Answer» C. 2.4
89.

Which of the following statement is wrong regarding Anthracite?

A. It requires less water
B. It is less inert to caustic solutions than sand
C. It is more costly per tonne than sand
D. It is used in industrial filters.
Answer» C. It is more costly per tonne than sand
90.

In which device, the primary mixing is followed by a secondary reaction zone resulting in formation of sludge blanket?

A. Centrifugal pump
B. Flocculator
C. Tube settler
D. Solid contact clarifier
Answer» E.
91.

The design value of the velocity of flow in a flocculator is _______

A. 0.2-0.8m/s
B. 0.3-0.5m/s
C. 0.6-0.8m/s
D. 0.1-0.5m/s
Answer» B. 0.3-0.5m/s
92.

What is the desirable value of mean velocity gradient in a flocculator?

A. 20-50sec⁻¹
B. 20-75sec⁻¹
C. 50-100sec⁻¹
D. 30-50sec⁻¹
Answer» C. 50-100sec⁻¹
93.

What is the dimension formula of mean velocity gradient?

A. 1/T
B. 1/T²
C. T
D.
Answer» B. 1/T²
94.

In which type of sedimentation, flocculent suspension of intermediate concentration takes place?

A. Type I sedimentation
B. Type II sedimentation
C. Type III sedimentation
D. Type IV sedimentation
Answer» D. Type IV sedimentation
95.

In which settling type, dilute suspension of particles takes place?

A. Zone settling
B. Compression settling
C. Hindered settling
D. Discrete settling
Answer» D. Discrete settling
96.

In which type of sedimentation, flocculent suspension of high concentration takes place?

A. Type I sedimentation
B. Type II sedimentation
C. Type III sedimentation
D. Type IV sedimentation
Answer» E.
97.

When impurities are separated by the gravitation of settling particles, the operation is called _____

A. Sedimentation with coagulant
B. Plain sedimentation
C. Secondary sedimentation
D. Disinfection
Answer» C. Secondary sedimentation
98.

Which of the following represents the impeller shaft in the following figure?

A. F
B. E
C. C
D. B
Answer» B. E
99.

‘C’ in the following figure represents the ________

A. Impeller
B. Impeller shaft
C. Deflecting wall
D. Flash mixer wall
Answer» D. Flash mixer wall
100.

The speed of impeller in a flash mixer is ___________

A. 45rpm
B. 60rpm
C. 110rpm
D. 200rpm
Answer» D. 200rpm