CPCB Recruitment Examination 2022
Q.1 – Q.30: Section 1 (Carry ONE Mark Each)
Q.1 – Q.20: MCQ (1/6 Negative Marking)
Q.1 9 2 0
Consider a Matrix A = [1 3 4]. Determinant of A is
1 2 0
(A) −64
(B) −80
(C) 80
(D) 64
Q.2 Value of lim 𝑥 𝑛 ln 𝑥 is
𝑥→0
(A) 0
(B) 1
(C) n
(D) 1/n
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.3 ß-1,4-glycosidic linkage is found in
(A) cellulose
(B) glycogen
(C) amylose
(D) amylopectin
Q.4 Which of the following is NOT considered as a greenhouse gas?
(A) CO2
(B) CH4
(C) H2O
(D) NH3
Q.5 A nucleoside is only made up of
(A) pentose sugar, nitrogenous base and phosphate groups
(B) pentose sugar and nitrogenous base
(C) nitrogenous base and phosphate groups
(D) pentose sugar and phosphate groups
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.6 Pyruvate is the terminal electron acceptor in
(A) methanogenesis
(B) acetogenesis
(C) lactic acid fermentation
(D) aerobic respiration
Q.7 Consider the following with respect to an aquifer
S – storage coefficient
Sy – specific yield
n - porosity
The correct option is
(A) S = Sy
(B) S > Sy
(C) S < Sy
(D) S + Sy = n
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.8 Shear characteristics of the fluids/materials are shown in the figure
Shear stress
0 S
Velocity gradient
Match the columns
Column 1 Column 2
P I. Ideal fluid
Q II. Newtonian fluid
R III. Non-Newtonian fluid
S IV. Bingham Plastic
Correct match is
(A) P → I; Q → III; R → II; S → IV
(B) P → I; Q → II; R → III; S → IV
(C) P → IV; Q → III; R → II; S → I
(D) P → IV; Q → II; R → III; S → I
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.9 Consider the following two statements
P: Hyetograph is a plot of rainfall depth vs time.
Q: An isohyet is a line joining points having equal height above mean sea
level (MSL).
The correct option is
(A) P is TRUE; Q is FALSE
(B) P is FALSE; Q is TRUE
(C) P is TRUE; Q is TRUE
(D) P is FALSE; Q is FALSE
Q.10 Regarding the pipes used in the water supply networks and sewerage networks,
which one of the following statements is true?
(A) Flow in the water supply pipes is under pressure and hence slope of the pipes is
very important.
(B) Flow in the sewerage pipes is under pressure and hence slope of the pipes is very
important.
(C) Flow in the water supply pipes is open channel flow and hence slope of the pipes
is very important.
(D) Flow in the sewerage pipes is open channel flow and hence slope of the pipes is
very important.
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.11 While raw sewage is considered to be a low strength wastewater, distillery
wastewater (spent wash) is considered to be a high strength wastewater. Their
respective BOD5 values are approximately
(A) 200 mg/L and 25,000 mg/L
(B) 200 mg/L and 45,000 mg/L
(C) 600 mg/L and 65,000 mg/L
(D) 600 mg/L and 85,000 mg/L
Q.12 Which one of the following gaseous air pollutants affects the visibility most
significantly?
(A) SO2
(B) O3
(C) NO2
(D) CO
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.13 Elemental mercury (Hg0) is considered to be a hazardous air pollutant (HAP). The
approximate lifetime of Hg0 in the air is
(A) 1 day
(B) 1 month
(C) 1 year
(D) 10 years
Q.14 As per WHO noise pollution guidelines, the limits of A-weighted equivalent
continuous sound pressure level (LAeq) over 24-hour period for outdoor residential
areas and outdoor commercial areas, respectively, are
(A) 55 dB and 70 dB
(B) 30 dB and 50 dB
(C) 70 dB and 110 dB
(D) 40 dB and 80 dB
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.15 Theoretically, the correct sequence representing biomethanation of organic waste is
(A) acidogenesis → acetogenesis → hydrolysis → methanogenesis
(B) hydrolysis → acetogenesis → acidogenesis → methanogenesis
(C) hydrolysis → acidogenesis → acetogenesis → methanogenesis
(D) acetogenesis → acidogenesis → hydrolysis → methanogenesis
Q.16 According to the Bio-Medical Waste Management Rules, 2016, the Yellow bags
containing human and animal anatomical wastes, wastes contaminated with
blood/body fluids, etc. should be processed by
(A) microwave treatment followed by shredding
(B) autoclaving or hydroclaving
(C) gasification followed by syngas utilization
(D) incineration or plasma pyrolysis
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.17 Conventional thermal power plants release large amounts of CO2. However, CO2
capture in these facilities for sequestration is usually not feasible because
(A) large amount of particulate matter is present in the exhaust gas
(B) it is difficult to remove the water vapour present in the exhaust gas
(C) selective absorption of the CO2 generated is not possible
(D) CO2 generated gets diluted with the large amount of N2 from the combustion air
Q.18 HFCs and HCFCs are a few alternatives to the conventional ozone depleting
substances. They usually do not reach the stratosphere because
(A) of their large molecular weights
(B) they are very reactive and react with O3 in the lower atmosphere
(C) they are destroyed by the UV-rays reaching the earth
(D) the H atoms present in these gases react with hydroxyl radicals in the lower
atmosphere
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.19 India is mostly dependent on the conventional thermal power plants and
hydroelectric power plants for meeting its power requirements. A small fraction
comes from the nuclear power plants as well. The option that gives the best way of
balancing the Base load and Peak load power requirements is
(A) Base load: thermal + nuclear power plants; Peak load: hydroelectric power plants
(B) Base load: thermal + hydroelectric power plants; Peak load: nuclear power plants
(C) Base load: hydroelectric + nuclear power plants; Peak load: thermal power plants
(D) Base load: thermal power plants; Peak load: nuclear + hydroelectric power plants
Q.20 Lake XYZ is used by local fishermen for their livelihood. A nearby factory is
releasing pollutants which is adversely affecting the production and quality of fish
harvested from the lake. What action should be taken as per the precautionary
principle?
(A) Allow factory to remain operational until more evidence are generated.
(B) Ask fishermen to continue fishing with reduced harvest and some compensation.
(C) Stop the release of pollutants and clean up the existing damage to the lake.
(D) Ask fishermen to look for alternate livelihood.
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.21 – Q.30: MSQ/NAT (No Negative Marking)
Q.21 Correction option(s) for a unit matrix is/are
(A) 1 1
[ ]
1 1
(B) 1 0
[ ]
0 1
(C) 1 0
[ ]
0 0
(D) 0 0
[ ]
0 1
Q.22 16S rRNA gene is a phylogenetic marker for
(A) Bacteria
(B) Archaea
(C) Fungi
(D) Protists
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.23 Self purification constant (fs) of a river depends on the deoxygenation constant (rd)
and reaeration constant (ra). For a river, considering log base to e, rd = 0.30/day and
ra = 0.70/day. The correct option(s) is/are
(A) fs of the river = 0.50
(B) fs of the river = 0.43
(C) the river is likely to be a fast moving river with high turbulence
(D) the river is likely to be a slow moving river with low turbulence
Q.24 Which of the following air pollutant(s) is/are considered as ‘criteria air pollutants’
in India?
(A) PM2.5
(B) SO2
(C) NH3
(D) NO2
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.25 Within integrated solid waste management, which of the following is/are the
approach(es) for ‘source reduction’?
(A) landfilling
(B) less packaging
(C) incineration
(D) product reuse
Q.26 Which of the following is/are true for ocean acidification?
(A) It is responsible for loss of coral reefs.
(B) It reduces the availability of calcium bicarbonate.
(C) It reduces the availability of calcium carbonate.
(D) It is caused due to increasing atmospheric concentration of CO2.
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.27 Which of the following statement(s) is/are true about ‘polluter pays principle’?
(A) Polluter pays principle imposes a charge on the emission of the greenhouse gases
equivalent to the cost of damage caused to the environment and society, thus forcing
the polluter to internalize its cost.
(B) Every generation is under an obligation to preserve its natural and cultural heritage
for enjoyment for the future generations.
(C) Polluter pays principle means that the absolute liability for harm to the environment
extends only to compensate the victims of pollution but not the cost of restoring the
environmental degradation.
(D) To ensure the implementation of the polluter pays principle, the ambiguity which
exists regarding ‘who is the polluter’ has to be done away with.
Q.28 The Sodium Absorption Ratio for a soil containing Ca2+, Mg2+ and Na+ in
concentrations of 5 mEq/L, 3 mEq/L and 8 mEq/L, respectively, is ___________
(in integer). 4
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.29 A 6-hour unit hydrograph (for 1 cm rainfall excess) for a catchment is shown in the
figure (not to scale).
20
Discharge (m3/s)
10
645-650
0 60 120 180
Time (hour)
Area of the catchment is ______________ (in km2, rounded off to two decimal
places).
Q.30 A fully penetrating well is installed in a homogenous and isotropic unconfined
aquifer. The saturated thickness of aquifer is 20 m and hydraulic conductivity is
8 m/day. Water is being pumped out from the well at a constant rate of 0.05 m 3/s
till steady state condition is reached. If a drawdown of 3.0 m is observed at a
distance of 100 m from the well then the drawdown at a distance of 150 m from the
well will be ______________ (in m, rounded off to two decimal places).
1.02-1.10
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.31 – Q.50: Section 2 (Carry TWO Marks Each)
Q.31 – Q.40: MCQ (2/6 Negative Marking)
Q.31 Area of the region enclosed by curves 𝑦 = 𝑥 + 2 and 𝑦 = 𝑥 2 + 2 is
(A) 1/2
(B) 1/3
(C) 1/6
(D) 5/6
Q.32 If the probability density function of a continuous random variable is given by
𝑓(𝑥) = 𝑒 −𝑥 0 ≤ 𝑥 < ∞. The mean is
(A) 0
(B) 1
(C) 2
(D) e
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.33 The following reactions occur in the stratosphere
Cl + O3 → ClO + O2
ClO + NO → Cl + NO2
ClO + O → Cl + O2
NO2 + h → NO + O
O + O2 + M → O3 + M
The catalytic cycle of reactions that destroys ozone is
(A) Cl + O3 → ClO + O2
ClO + NO → Cl + NO2
(B) Cl + O3 → ClO + O2
ClO + O → Cl + O2
(C) Cl + O3 → ClO + O2
O + O2 + M → O3 + M
(D) Cl + O3 → ClO + O2
NO2 + h → NO + O
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.34 The fluidity of cell membrane of bacteria is NOT determined by
(A) length of the fatty acyl chains
(B) level of unsaturation of the fatty acyl chains
(C) level of cholesterol in the cell membrane
(D) extent of branching of the fatty acyl chains
Q.35 A pipe of length l and diameter d was connected between two points for water
supply. Later l/4 part of the pipe was found damaged and also a pipe of the same
diameter is not available. So a pipe of same material having diameter 1.25 d and
length l/4 is planned to be used for replacing the damaged length. After the
replacement, the discharge will increase by
(A) 4.8 %
(B) 9.6 %
(C) 12.5 %
(D) 25.0 %
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.36 Consider the following figure (not to scale) between rainfall intensity and time for
a 5-hour rainfall event.
Rainfall intensity (cm/hour)
1.5
1.0
0.5
0 1 2 3 4 5
Time (hour)
If this rainfall event produces a direct runoff of 2.15 cm, then the ϕ–index is
(A) 1.50 cm/hour
(B) 0.37 cm/hour
(C) 0.40 cm/hour
(D) 0.25 cm/hour
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.37 The following table gives various types of water/wastewater and a list of treatment
options
Type of water/wastewater Treatment options
P. Water with high turbidity I. Sequential Batch Reactor (SBR)
Q. Coloured effluents from CETPs II. Adsorption with activated carbon
R. Organic wastewater III. Thickening - anaerobic digestion
S. Sewage sludge IV. Coagulation - settling
The correct match of the type of water/wastewater and the commonly used
treatment option is
(A) P → II, Q → IV, R → III, S → I
(B) P → IV, Q → I, R → III, S →II
(C) P → II, Q → III, R → IV, S →I
(D) P → IV, Q → II, R → I, S → III
Q.38 The number density of PM2.5 particles in ambient air is 10,000 particles per cm3. If
the particles have a uniform diameter of 150 nm and a material density of 1.5 g/cm3,
then the approximate mass concentration of PM2.5 particles is
(A) 19.83 g/m3
(B) 35.27 g/m3
(C) 20.51 g/m3
(D) 26.49 g/m3
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.39 Cyclone separators are used to remove particulate matter from flue gases in various
industries. For a cyclone separator with a cut diameter (d50) of 2.5 m, the fractional
efficiency in removing particles of diameter 5 m will be
(A) 50 %
(B) 80 %
(C) 25 %
(D) 100 %
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.40 A city generates 1000 tons/day of municipal solid waste (MSW) of the following
composition (% by weight)
Paper 10
Kitchen waste 40
Ferrous metals 3
Non-ferrous metals 2
Glass 4
Textiles 3
Soil/bricks/concrete 30
Rubber/leather 3
Paper board/card board 5
The amount of material that can be used from this MSW for making Refuse Derived
Fuel (RDF) is
(A) 180 tons/day
(B) 210 tons/day
(C) 580 tons/day
(D) 610 tons/day
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.41 – Q.50: MSQ/NAT (No Negative Marking)
Q.41 𝑑𝑦
Possible solution(s) of ordinary differential equation − 𝑡𝑦 = 2𝑡 is/are
𝑑𝑡
(A) 𝑦 = −2
2 ⁄2
(B) 𝑦 = 3𝑒 𝑡 −2
2 ⁄2
(C) 𝑦 = 2𝑒 𝑡 −3
2
(D) 𝑦 = 𝑒𝑡 − 2
Q.42 Which of the following statement(s) is/are true?
(A) Under the Kyoto Protocol, the developing countries were required to reduce their
greenhouse gas emissions by a certain percentage, compared to their emissions in
1990.
(B) India is one of the founding countries of International Solar Alliance.
(C) The central aim of Paris Agreement signed in 2015 is to strengthen the global
response to climate change for keeping global temperature rise this century well
below 2 C.
(D) Each Party to the Paris Agreement is required to establish an NDC (Nationally
Determined Contribution – a climate action plan to cut emissions and adapt to
climate impacts) and update it every five years.
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.43 The atmosphere contains about 3.9×1018 kg of elemental nitrogen gas. The major
natural sinks of atmospheric nitrogen are biological nitrogen fixation
(2×1011 kg/year), deposition of HNO3 along with rainwater (7×1010 kg/year), and
nitrogen fixation through industrial processes (5×1010 kg/year). Estimated residence
time of nitrogen in the atmosphere is ___________ (in million years, rounded off to
one decimal place).
12-12.4
Q.44 A parking lot produced a runoff 0.5 m3/s for a rainfall event. A triangular shaped
drain (with side slope 1 V : 1.5 H and with bed slope 1 in 100) disposes the runoff
from this parking lot to a nearby stream. If Manning’s roughness coefficient of the
drain material is 0.015, then the depth of flow would be _____________ (in m,
rounded off to two decimal places).
0.38-0.42
Q.45 Beds of two reservoirs are connected through a confined aquifer of uniform
thickness 10 m, hydraulic conductivity 5 m/day, and effective porosity 0.35. Head
difference between the reservoirs is 15 m, and the length of the aquifer between the
reservoirs is 2 km. If the upper reservoir is contaminated, then the time taken by the
contaminant to reach the lower reservoir due to advective flow is _____________
(in years, rounded off to two decimal places).
50-52
Q.46 In a water treatment plant, the primary clarifier was originally designed for
removing discrete particles of diameter 0.04 mm and above. Due to some
emergency, the surface overflow rate (SOR) of this clarifier needs to be increased
by 50 % now. Assuming Stokes law is applicable, the minimum diameter of the
particles that will be removed by the clarifier is _______ (in mm, rounded off to
three decimal places).
0.047-0.051
Q.47 5th day and 10th day BOD values of a wastewater sample are 300 mg/L and
350 mg/L, respectively. Assuming natural logarithm, the deoxygenation rate
constant of this wastewater is __________ (in day-1, rounded off to two decimal
places).
0.35-0.37
Environmental Engg.
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CPCB Recruitment Examination 2022
Q.48 The average mass concentration of SO2 in the ambient air at a location is 50 g/m3.
At 15oC and 1 atmospheric pressure, the mass mixing ratio of SO2 over this location
is _________ (in parts per billion, rounded off to two decimal places).
18.4-18.5
Q.49 Sewage is treated in a treatment plant as shown in the figure below.
Losses
Settling tank Aeration tank Settling tank
Sewage 1000 t/h Effluent 900 t/h
Recycle 200 t/h
Sludge 50 t/h
Air 300 t/h
Sludge 300 t/h
The material flow through the various units are shown in tons/hour (t/h). The loss
of matter from the aeration tank is __________ (in tons/hour, in integer).
50
Q.50 Drinking water from a source contains 0.01 mg/L of tetrachloroethylene which is a
carcinogen with the oral potency factor of 5.1×10−2 (mg/kg day)−1. The carcinogenic
risk faced by an individual (weight 70 kg, expected lifespan of 70 years) drinking 2
L/day of water for 10 years is _________ (in 10−6, rounded off to two decimal
places).
Environmental Engg.
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