WorksheetsD61 MASTER THE DAY
Total questions: 113
Worksheet time: 2hrs 53mins
Name
Class
Date
1.
What type of manhole is constructed at the start of a branch sewer and is less than 1m deep?
a)
Normal manhole
b)
Drop manhole
c)
Shallow manhole
d)
Deep manhole
2.
Which zone of pollution is known for maximum anaerobic decomposition and gas evolution?
a)
Clear water zone
b)
Zone of active decomposition
c)
Zone of recovery
d)
Zone of degradation
3.
Which type of storm regulator works on siphonic action to divert excess water?
a)
Leaping weir
b)
Overflow weir
c)
Siphon spillway
d)
Catch basin
4.
In which type of lake does the euphotic zone extend up to the hypolimnion?
a)
Mesotrophic lake
b)
Eutrophic lake
c)
Oligotrophic lake
d)
Senescent lake
5.
What is the minimum cover diameter for a circular manhole cover as per IS?
a)
40 cm
b)
50 cm
c)
60 cm
d)
70 cm
6.
What happens during thermal stratification in lakes during summer?
a)
Water becomes uniform in temperature
b)
Epilimnion rises and mixes
c)
Three distinct layers form
d)
Water freezes
7.
Which material is typically used for manhole walls?
a)
PVC
b)
Steel
c)
Brick, stone or concrete
d)
Plastic
8.
Where are grease traps usually located in a sewer system?
a)
At sewer outlet
b)
Near sewage treatment plant
c)
Near kitchens and garages
d)
At inlets
9.
Which pipe is inclined from sewer to ground surface and covered at top?
a)
Drop pipe
b)
Lamp hole
c)
Cleanout
d)
Flushing pipe
10.
What is the effect of adding lime to a eutrophic lake?
a)
Reduces nitrogen
b)
Increases turbidity
c)
Removes phosphorus
d)
Promotes algal bloom
11.
Which method is used to calculate the area of land required for sewage disposal?
a)
A = B × H
b)
A = Q / CC
c)
A = D × T
d)
A = Q × P
12.
What does the term 'sleek' refer to in marine sewage disposal?
a)
Submerged sludge bank
b)
Odour-free discharge
c)
Sewage film on sea surface
d)
Filtered effluent
13.
What happens to sewage solids that react with sea water?
a)
Become acidic
b)
Form sludge banks
c)
Float on top
d)
Evaporate
14.
Which of the following increases crop yield by 33%?
a)
Fertilizer irrigation
b)
Canal irrigation
c)
Sewage farming
d)
Drip irrigation
15.
What causes sewage sickness in land treatment systems?
a)
Over-fertilization
b)
Poor water quality
c)
Anaerobic soil conditions due to clogging
d)
Excess irrigation
16.
What is the typical spacing of inlets or gullies for stormwater drainage?
a)
5–10 m
b)
10–30 m
c)
30–60 m
d)
60–100 m
17.
What is the primary function of a flushing tank in a dead-end sewer line?
a)
Measure flow
b)
Store stormwater
c)
Create self-cleansing velocity
d)
Separate grease
18.
Which lake type is in its final stage of aging with dense plant growth and marshy bottom?
a)
Eutrophic lake
b)
Oligotrophic lake
c)
Senescent lake
d)
Mesotrophic lake
19.
Assertion (A): Lakes undergo overturning in winter.
Reason (R): Cooling increases surface water density, causing mixing.
a)
Both A and R are true, and R explains A
b)
Both A and R are true, but R does not explain A
c)
A is true, R is false
d)
A is false, R is true
20.
Which of the following is NOT a sewer appurtenance?
a)
Manhole
b)
Drop manhole
c)
Gully trap
d)
Sewer pump
21.
Which zone of a river has DO increasing to 40% and aquatic life starting to return?
a)
Clear water zone
b)
Zone of recovery
c)
Zone of degradation
d)
Zone of active decomposition
22.
Which chamber is constructed in place of a manhole at the upper ends of lateral sewers?
a)
Catch basin
b)
Cleanout
c)
Drop manhole
d)
Lamp hole
23.
Which parameter has a maximum limit of 600 mg/l for discharge into public sewers?
a)
TSS
b)
BOD
c)
pH
d)
COD
24.
During lake overturning in winter, which phenomenon occurs?
a)
Epilimnion freezes completely
b)
Surface water cools and sinks
c)
Hypolimnion evaporates
d)
Anaerobic condition at top
25.
Which appurtenance is used where manhole construction is difficult but flushing is required?
a)
Cleanout
b)
Flushing tank
c)
Lamp hole
d)
Catch basin
26.
Which type of inlet is placed at the curb with vertical grating?
a)
Gutter inlet
b)
Horizontal inlet
c)
Curb inlet
d)
Combined inlet
27.
What is the result of continuous application of untreated sewage on soil?
a)
Improved fertility
b)
Higher yield
c)
Sewage sickness
d)
Soil desalination
28.
Which zone in a polluted river has saturated DO and fully restored aquatic life?
a)
Zone of recovery
b)
Zone of degradation
c)
Clear water zone
d)
Zone of active decomposition
29.
Which lake zone is most suitable for rooted aquatic plant growth?
a)
Euphotic zone
b)
Benthic zone
c)
Littoral zone
d)
Metalimnion
30.
What is the typical shape of a manhole cover used in roads?
a)
Square
b)
Rectangular
c)
Circular
d)
Triangular
31.
Why is the thickness of manhole sidewalls calculated as t = 10 + 4d?
a)
To support traffic loads
b)
To retain earth pressure with depth
c)
To resist hydraulic pressure
d)
For aesthetic design
32.
What is the function of a siphon spillway in stormwater systems?
a)
Divert sewage gases
b)
Intercept stormwater and discharge it
c)
Act as a barrier for debris
d)
Aerate the stormwater
33.
Assertion (A): Storm regulators reduce the load on pumping stations.
Reason (R): They divert all sewage to natural streams.
a)
Both A and R are true and R explains A
b)
Both A and R are true but R does not explain A
c)
A is true, R is false
d)
A is false, R is true
34.
Which appurtenance provides access for inspection and cleaning in straight sewer sections?
a)
Catch basin
b)
Manhole
c)
Gully trap
d)
Grease trap
35.
In sea disposal, what is the minimum required depth at the sewage outfall?
a)
1–2 m
b)
3–5 m
c)
6–10 m
d)
10–15 m
36.
Which method of sewage disposal increases BOD tolerance to 500 mg/L?
a)
River dilution
b)
Lake disposal
c)
Sewage farming
d)
Sea disposal
37.
Statement: The benthic zone lies at the lake bottom and contains organic sediments.
Is this statement True or False?
a)
True
b)
False
c)
Only during summer
d)
Cannot say
38.
Which river pollution zone is located just below the outfall sewer?
a)
Zone of recovery
b)
Zone of degradation
c)
Zone of active decomposition
d)
Clear water zone
39.
What is the primary cause of oxygen deficit in polluted water?
a)
Atmospheric pressure
b)
Sunlight intensity
c)
Decomposition of organic matter
d)
High pH
40.
What type of lake has moderate algal growth and turbidity?
a)
Eutrophic lake
b)
Mesotrophic lake
c)
Senescent lake
d)
Oligotrophic lake
41.
Which biological zone in lakes allows light penetration and supports photosynthesis?
a)
Littoral zone
b)
Euphotic zone
c)
Benthic zone
d)
Hypolimnion
42.
What is the main reason for high turbidity in eutrophic lakes?
a)
Deep water
b)
Low productivity
c)
Abundant aquatic life
d)
Excessive algal growth
43.
Assertion (A): Oligotrophic lakes are ecologically balanced.
Reason (R): They are shallow with rich nutrients.
a)
Both A and R are true, and R explains A
b)
Both A and R are true, but R does not explain A
c)
A is true, R is false
d)
A is false, R is true
44.
What is the zone where sunlight stimulates algae which then produce oxygen?
a)
Euphotic zone
b)
Hypolimnion
c)
Benthic zone
d)
Thermocline
45.
What is the pH tolerance range for domestic sewage disposal into water sources?
a)
4.5 – 6
b)
5.5 – 9
c)
6.5 – 7.5
d)
7 – 9.5
46.
What is the primary function of sedimentation in rivers during self-purification?
a)
Kill bacteria
b)
Add oxygen
c)
Settle suspended solids
d)
Evaporate water
47.
In self-purification, what is the source of oxygen for reoxygenation?
a)
Decomposed matter
b)
Sunlight
c)
Atmospheric diffusion and turbulence
d)
Algae removal
48.
Which component of a manhole prevents accidents and allows road traffic over it?
a)
Access shaft
b)
Working chamber
c)
Side wall
d)
Cover and frame
49.
In dilution disposal, what does a dilution factor (DF) > 500 indicate?
a)
Primary treatment needed
b)
No treatment needed
c)
All treatment required
d)
Only chemical treatment
50.
What is the process of reoxygenation in river self-purification supported by?
a)
Algae growth
b)
Sunlight absorption
c)
Rain, wind, turbulence
d)
Sedimentation
51.
Which form of lake disposal occurs when surface sewage rises as a thin film?
a)
Sleek
b)
Sludge bank
c)
Eutrophication
d)
Overturn
52.
Which force in river purification settles heavier solids to the bed?
a)
Sunlight
b)
Dilution
c)
Sedimentation
d)
Oxidation
53.
Statement: Sludge banks in sea disposal increase seawater’s absorption capacity. Is this statement True or False?
a)
True
b)
False
c)
Partially true
d)
Cannot say
54.
Which is an anaerobic zone in polluted river where DO falls to zero?
a)
Zone of degradation
b)
Zone of active decomposition
c)
Zone of recovery
d)
Clear water zone
55.
What is the result of reduction process in self-purification?
a)
Oxygen is added
b)
Organic matter settles
c)
Gases and liquids are formed by bacteria
d)
Water becomes alkaline
56.
Which parameter is used to assess oxygen deficiency at a river point?
a)
pH
b)
Temperature
c)
Oxygen deficit
d)
Alkalinity
57.
Assertion (A): Reoxygenation occurs faster in shallow rivers.
Reason (R): Shallow rivers have higher surface area for oxygen transfer.
a)
Both A and R are true, and R explains A
b)
Both A and R are true, but R does not explain A
c)
A is true, R is false
d)
A is false, R is true
58.
Which method is suitable for wastewater disposal when the soil is porous and sandy?
a)
Dilution
b)
Broad irrigation
c)
Septic tank disposal
d)
Mechanical treatment
59.
Which type of vegetation is avoided in sewage farms due to hygiene concerns?
a)
Cash crops
b)
Coconut trees
c)
Leafy vegetables
d)
Wheat
60.
What is the effect of sewage sickness on land?
a)
Increased fertility
b)
Clogged soil and anaerobic condition
c)
Enhanced oxygen in soil
d)
Soil becomes alkaline
61.
Which pollutant parameter has the highest permissible limit in public sewer discharge?
a)
BOD
b)
TSS
c)
COD
d)
pH
62.
Assertion (A): Rooted aquatic plants grow in benthic zone.
Reason (R): Benthic zone has high light penetration.
a)
Both A and R are true and R explains A
b)
Both A and R are true but R does not explain A
c)
A is true, R is false
d)
A is false, R is true
63.
Which component of lake productivity directly affects fish population?
a)
Turbidity
b)
Thermocline thickness
c)
Primary productivity
d)
Salt concentration
64.
Which layer forms a transition between warm and cold zones in lakes?
a)
Epilimnion
b)
Hypolimnion
c)
Metalimnion (thermocline)
d)
Littoral zone
65.
What happens to lake water during overturning?
a)
Thermocline thickens
b)
Water layers remain static
c)
Top and bottom layers mix
d)
Hypolimnion evaporates
66.
In what zone is the algae population rare and oxygen levels at maximum?
a)
Zone of active decomposition
b)
Zone of degradation
c)
Clear water zone
d)
Zone of recovery
67.
Which lake type represents the final stage of aging?
a)
Oligotrophic lake
b)
Eutrophic lake
c)
Senescent lake
d)
Mesotrophic lake
68.
Which form of oxygen depletion happens due to high organic loading?
a)
Saturation
b)
Oxygen deficit
c)
Supersaturation
d)
Evaporation loss
69.
Match the following: A) Oligotrophic – Deep clear water B) Eutrophic – High productivity C) Mesotrophic – marshy condition D) Senescent – Moderate algae
a)
A-1, B-2, C-3, D-4
b)
A-2, B-1, C-3, D-4
c)
A-1, B-2, C-4, D-3
d)
A-1, B-2, C-3, D-4
70.
Which of the following is not suitable for sewage farming?
a)
Clayey soil
b)
Loamy soil
c)
Sandy soil
d)
Silty loam
71.
How can sewage sickness be prevented?
a)
Avoid rest to land
b)
Use clay soil
c)
Use untreated sewage continuously
d)
Give rest to land and use sandy soil
72.
Which lake zone lies at the very bottom and has organic sediments?
a)
Littoral zone
b)
Benthic zone
c)
Epilimnion
d)
Metalimnion
73.
Assertion (A): Mesotrophic lakes support medium aquatic life.
Reason (R): These lakes have low nutrient content.
a)
Both A and R are true and R explains A
b)
Both A and R are true but R does not explain A
c)
A is true, R is false
d)
A is false, R is true
74.
Which force in river purification is directly responsible for reducing concentration of pollutants?
a)
Sunlight
b)
Dilution and dispersion
c)
Turbulence
d)
Rainfall
75.
What is the standard BOD limit for industrial effluent discharged into inland surface water?
a)
20 mg/l
b)
30 mg/l
c)
100 mg/l
d)
500 mg/l
76.
Which element in sewage causes eutrophication?
a)
Lead
b)
Phosphorus
c)
Iron
d)
Calcium
77.
Which of the following is a self-purification chemical process?
a)
Evaporation
b)
Oxidation
c)
Turbulence
d)
Diffusion
78.
Assertion (A): Grease traps are installed near sources like kitchens.
Reason (R): They allow grease to enter main sewer line easily.
a)
Both A and R are true and R explains A
b)
Both A and R are true but R does not explain A
c)
A is true, R is false
d)
A is false, R is true
79.
What happens at the critical point of oxygen sag curve?
a)
Oxygen deficit is minimum
b)
Oxygen deficit is maximum
c)
DO becomes zero
d)
Reoxygenation stops
80.
Which component in a manhole helps support soil pressure and upper components?
a)
Cover and frame
b)
Steps
c)
Sidewalls
d)
Invert
81.
Which zone in polluted water has increased CO₂ and reduced oxygen?
a)
Clear water zone
b)
Zone of degradation
c)
Zone of recovery
d)
Zone of active decomposition
82.
Statement: Grease and oil traps are located near workshops and garages.
Is this statement True or False?
a)
True
b)
False
c)
Partially true
d)
Cannot determine
83.
Which of the following is used to inspect and clean sewer lines where manhole construction is difficult?
a)
Catch basin
b)
Lamp hole
c)
Cleanout
d)
Drop pipe
84.
Which of the following factors influences the rate of reoxygenation in rivers?
a)
Oxygen deficit and temperature
b)
COD only
c)
Depth of river only
d)
Length of river
85.
Which structure is constructed to divert excess sewage during heavy rainfall?
a)
Drop manhole
b)
Storm regulator
c)
Lamp hole
d)
Catch pit
86.
What is the typical diameter of a circular manhole access shaft?
a)
0.4–0.6 m
b)
0.5–0.8 m
c)
0.6–0.75 m
d)
0.75–1.0 m
87.
What is the purpose of the working chamber in a deep manhole?
a)
Outlet control
b)
Provide access to equipment
c)
Allow maintenance and inspection
d)
Reduce pressure
88.
In sea disposal, which of the following can help avoid formation of sludge banks?
a)
Discharge sewage close to shore
b)
Discharge in shallow waters
c)
Use deep sea outfalls
d)
Allow floating layers
89.
Which method of disposal is followed when treated sewage is released into river or lake?
a)
Effluent irrigation
b)
Land treatment
c)
Dilution
d)
Mechanical treatment
90.
What type of flow occurs in inverted siphons used in sewer lines?
a)
Gravity flow
b)
Free surface flow
c)
Pressure flow
d)
Intermittent flow
91.
Assertion (A): Combined system of sewerage is more economical.
Reason (R): It requires fewer sewers and manholes.
a)
Both A and R are true and R explains A
b)
Both A and R are true but R does not explain A
c)
A is true, R is false
d)
A is false, R is true
92.
Which zone in a polluted river is characterized by formation of gases like methane and hydrogen sulfide?
a)
Zone of degradation
b)
Zone of recovery
c)
Clear water zone
d)
Zone of active decomposition
93.
Match the following:
A) Catch basin – Temporary storage for stormwater
B) Flushing tank – Cleans sewer by flow
C) Clean-out – Access point for rods
D) Storm regulator – Diverts excess flow
a)
A-2, B-1, C-4, D-3
b)
A-1, B-2, C-3, D-4
c)
A-3, B-4, C-1, D-2
d)
A-4, B-3, C-2, D-1
94.
Which of the following is an advantage of sewage farming?
a)
Causes foul smell
b)
Promotes groundwater contamination
c)
Provides irrigation and nutrients to crops
d)
Increases mosquito breeding
95.
Which parameter is most commonly used to measure organic pollution in water?
a)
pH
b)
Turbidity
c)
BOD
d)
DO
96.
Which zone in the oxygen sag curve immediately follows the zone of active decomposition?
a)
Zone of degradation
b)
Clear water zone
c)
Zone of recovery
d)
None of these
97.
Assertion (A): Self-purification is faster in rivers with turbulence.
Reason (R): Turbulence increases oxygen transfer from air to water.
a)
Both A and R are true and R explains A
b)
Both A and R are true but R does not explain A
c)
A is true, R is false
d)
A is false, R is true
98.
Which type of lake is formed due to glacial erosion?
a)
Tectonic lake
b)
Glacial lake
c)
Ox-bow lake
d)
Volcanic lake
99.
In which lake zone is photosynthesis most active?
a)
Benthic
b)
Profundal
c)
Epilimnion
d)
Hypolimnion
100.
Which of the following processes removes large floating objects from sewage?
a)
Grit chamber
b)
Sedimentation tank
c)
Screening
d)
Activated sludge process
101.
Statement: Ventilation pipes in sewers help release harmful gases.
Is the statement True or False?
a)
True
b)
False
c)
Partially true
d)
Cannot say
102.
Match the following: A) Epilimnion – Top sunlit layer B) Hypolimnion – thermoclinic region C) Metalimnion – Cold bottom layerD) Profundal zone – No sunlight
a)
A-3, B-1, C-4, D-2
b)
A-1, B-2, C-3, D-4
c)
A-4, B-3, C-2, D-1
d)
A-1, B-3, C-2, D-4
103.
What is the main purpose of a grit chamber in a sewage treatment plant?
a)
Remove floating solids
b)
Remove dissolved gases
c)
Remove heavy inorganic particles
d)
Increase DO
104.
Which of the following best defines 'Thermal Stratification' in lakes?
a)
Formation of algae layers
b)
Separation of water layers by temperature
c)
Pollution at the surface
d)
Mixing of all lake zones
105.
Which type of sewer system transports only domestic wastewater?
a)
Combined system
b)
Storm system
c)
Separate system
d)
Partial system
106.
Assertion (A): Lagoons are used for secondary treatment.
Reason (R): They utilize algae and bacteria for organic matter breakdown.
a)
Both A and R are true and R explains A
b)
Both A and R are true but R does not explain A
c)
A is true, R is false
d)
A is false, R is true
107.
What is the term for lakes that receive wastewater and gradually become shallow and marshy?
a)
Eutrophic lakes
b)
Oligotrophic lakes
c)
Tectonic lakes
d)
Dilution lakes
108.
Which is the correct order of zones in the oxygen sag curve downstream from a sewage outfall?
a)
Degradation → Active Decomposition → Recovery → Clear Water
b)
Clear Water → Recovery → Active Decomposition → Degradation
c)
Recovery → Clear Water → Decomposition → Degradation
d)
Decomposition → Recovery → Clear Water → Degradation
109.
Which lake zone has the lowest temperature and highest density?
a)
Epilimnion
b)
Metalimnion
c)
Hypolimnion
d)
Profundal
110.
Statement: Lakes play a role in groundwater recharge.
Is this statement True or False?
a)
True
b)
False
c)
Partially true
d)
Cannot determine
111.
Which method is most suitable for sewage disposal in coastal cities?
a)
Sewage farming
b)
Dilution in sea
c)
Subsoil irrigation
d)
Activated sludge process
112.
Match the following:
A) Lagoon – Biological treatment
B) Grit chamber – Inorganic removal
C) Skimming tank – Oil/grease removal
D) Screen – Floating matter removal
a)
A-1, B-2, C-3, D-4
b)
A-2, B-3, C-4, D-1
c)
A-4, B-1, C-2, D-3
d)
A-3, B-4, C-1, D-2
113.
Which bacteria are active during the zone of recovery in the oxygen sag curve?
a)
Anaerobic bacteria
b)
Pathogenic bacteria
c)
Aerobic bacteria and algae
d)
Fungi and protozoa
100 %
