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Objective Questions

Latest OSPCB Assistant Environmental Scientist Exam Question (Objective Questions), MCQ in English

Subjects : Ecology, Environmental Pollution and Management, Energy and Environment, Environmental Legislations, Major International efforts for environmental Protection, Current Environmental affairs in India, Logical Reasoning and Data Interpretation

Question Bank OSPCB Assistant Environmental Scientist Exam - English
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Ecology

Question 1Single Answer
Which sphere of the Earth contains all living organisms?
  1. AAtmosphere
  2. BBiosphere
  3. CLithosphere
  4. DHydrosphere
Question 2Single Answer
The major component of the atmosphere by volume is?
  1. AOxygen (~21%)
  2. BNitrogen (~78%)
  3. CCarbon dioxide (~0.04%)
  4. DArgon (~0.93%)
Question 3Single Answer
The layer of the atmosphere where the ozone layer is primarily located is?
  1. AThermosphere
  2. BTroposphere
  3. CMesosphere
  4. DStratosphere
Question 4Single Answer
The hydrological cycle is mainly associated with which environmental sphere?
  1. AAtmosphere
  2. BHydrosphere
  3. CLithosphere
  4. DBiosphere
Question 5Single Answer
Which process in the hydrological cycle returns water vapour to the atmosphere?
  1. APrecipitation
  2. BEvaporation and transpiration
  3. CInfiltration
  4. DRunoff
Question 6Single Answer
The uppermost layer of the Earth’s lithosphere that supports plant life is called?
  1. ABedrock
  2. BSoil
  3. CMantle
  4. DCrust
Question 7Single Answer
The rock cycle involves transformation among which three major rock types?
  1. AIgneous, sedimentary, metamorphic
  2. BOnly igneous and sedimentary
  3. COnly metamorphic and igneous
  4. DOnly sedimentary
Question 8Single Answer
Which of the following is NOT a biotic component of an ecosystem?
  1. ADecomposers
  2. BConsumers
  3. CProducers
  4. DSunlight
Question 9Single Answer
Organisms that convert solar energy into chemical energy are called?
  1. ADecomposers
  2. BPrimary consumers
  3. CSecondary consumers
  4. DProducers
Question 10Single Answer
In a food chain, the position occupied by an organism is called its?
  1. ATrophic level
  2. BNiche
  3. CHabitat
  4. DBiome

Environmental Pollution and Management

Question 11Single Answer
The physical parameter that indicates cloudiness or haziness in water due to suspended particles is?
  1. AColor
  2. BTurbidity
  3. COdour
  4. DTaste
Question 12Single Answer
The unit commonly used to express turbidity in drinking water analysis is?
  1. AJTU
  2. Bmg/L
  3. Cppm
  4. DNTU (Nephelometric Turbidity Units)
Question 13Single Answer
True color in water is measured after?
  1. ABoiling
  2. BAddition of acid
  3. CRemoval of turbidity by filtration or centrifugation
  4. DNo removal
Question 14Single Answer
The acceptable limit for turbidity in drinking water as per IS 10500:2012 is?
  1. A10 NTU
  2. B5 NTU (acceptable), 1 NTU (desirable)
  3. C1 NTU only
  4. DNo limit
Question 15Single Answer
The pH range for drinking water as per IS 10500 is?
  1. A6.5–8.5
  2. B5.0–9.0
  3. C7.0 only
  4. D4.0–10.0
Question 16Single Answer
Dissolved Oxygen (DO) in water is essential for?
  1. AHardness reduction
  2. BColor removal
  3. CSurvival of aquatic organisms
  4. DNo role
Question 17Single Answer
The saturation DO level in fresh water at 20°C is approximately?
  1. A5 mg/L
  2. B9.1 mg/L
  3. C15 mg/L
  4. D2 mg/L
Question 18Single Answer
Biochemical Oxygen Demand (BOd) measures?
  1. AAmount of oxygen required by microorganisms to decompose organic matter
  2. BChemical oxygen demand
  3. CTotal dissolved solids
  4. DNo demand
Question 19Single Answer
The standard incubation period and temperature for BOD test is?
  1. A3 days at 27°C
  2. B5 days at 20°C
  3. C7 days at 25°C
  4. D1 day at 37°C
Question 20Single Answer
Chemical Oxygen Demand (COd) measures?
  1. ANo oxidation
  2. BOnly biological oxidation
  3. COxygen required for chemical oxidation of organic and inorganic matter
  4. DOnly inorganic
Question 21Single Answer
The most commonly used oxidant in COD determination is?
  1. APotassium dichromate
  2. BPotassium permanganate
  3. COzone
  4. DHydrogen peroxide
Question 22Single Answer
Total hardness in water is mainly due to?
  1. ASodium ions
  2. BCalcium and magnesium ions
  3. CPotassium ions
  4. DNo hardness
Question 23Single Answer
The acceptable limit for total hardness in drinking water as per IS 10500 is?
  1. A200 mg/L
  2. B600 mg/L (acceptable), 300 mg/L (desirable)
  3. C1000 mg/L
  4. DNo limit
Question 24Single Answer
The method used for determination of hardness is?
  1. ASpectrophotometry
  2. BEDTA titrimetric method
  3. CGravimetry
  4. DNo method
Question 25Single Answer
Heavy metals of primary concern in water quality are?
  1. ANo metals
  2. BOnly iron
  3. COnly copper
  4. DLead, Cadmium, Mercury, Arsenic, Chromium
Question 26Single Answer
The permissible limit for arsenic in drinking water as per IS 10500 is?
  1. A0.01 mg/L
  2. B0.05 mg/L
  3. C0.1 mg/L
  4. D0.5 mg/L
Question 27Single Answer
The permissible limit for total coliform in drinking water as per IS 10500 is?
  1. A100 MPN/100 ml
  2. B10 MPN/100 ml
  3. CShall not be detectable in any 100 ml sample
  4. DNo limit
Question 28Single Answer
Faecal coliform (E. coli) limit in drinking water is?
  1. ANo limit
  2. B5 per 100 ml
  3. C10 per 100 ml
  4. DZero per 100 ml
Question 29Single Answer
Grab sampling in water quality monitoring is suitable when?
  1. ANo variation
  2. BSteady state
  3. CThe parameter is highly variable or instantaneous
  4. DLong-term average
Question 30Single Answer
Composite sampling is used when?
  1. AOnly grab
  2. BInstantaneous value
  3. CNo composite
  4. DAverage concentration over time is required
Question 31Single Answer
The most common laboratory method for measuring turbidity is?
  1. ATitrimetric
  2. BGravimetric
  3. CNephelometric method
  4. DSpectrophotometric
Question 32Single Answer
Spectrophotometry is commonly used for determination of?
  1. ANo use
  2. BOnly pH
  3. COnly DO
  4. DHeavy metals, phosphate, nitrate, etc.
Question 33Single Answer
The Winkler method is used for?
  1. ABOD
  2. BDissolved Oxygen determination
  3. CCOD
  4. DHardness
Question 34Single Answer
The dichromate reflux method is used for?
  1. ABOD
  2. BCOD determination
  3. CDO
  4. DpH
Question 35Single Answer
Continuous Effluent Quality Monitoring System (CEQMS) is mandatory for?
  1. AAll industries
  2. BHighly polluting industries (17 categories + grossly polluting)
  3. CNo industry
  4. DOnly small scale
Question 36Single Answer
CEQMS data must be transmitted in real-time to?
  1. ANo transmission
  2. BOnly industry
  3. CSPCB and CPCB servers
  4. DOnly local
Question 37Single Answer
Parameters commonly monitored under CEQMS include?
  1. ANo parameters
  2. BOnly pH
  3. COnly temperature
  4. DpH, BOD, COD, TSS, flow rate
Question 38Single Answer
The General Standards for Discharge of Environmental Pollutants (Schedule VI) are notified under?
  1. AAir Act 1981
  2. BWater Act 1974
  3. CEnvironment (Protection) Rules, 1986
  4. DNo schedule
Question 39Single Answer
As per General Standards, the limit for BOD in effluent discharged into inland surface water is?
  1. A10 mg/L
  2. B100 mg/L
  3. C30 mg/L
  4. DNo limit
Question 40Single Answer
The limit for pH in industrial effluent discharged into inland surface water is?
  1. A7.0 only
  2. B6.5–8.5
  3. C5.5–9.0
  4. D4.0–10.0

Energy and Environment

Question 41Single Answer
The Sun is considered the primary energy source for Earth because?
  1. AIt is the only source of fossil fuels
  2. BIt drives photosynthesis and the hydrological cycle
  3. CIt directly produces geothermal energy
  4. DIt has no role in climate
Question 42Single Answer
Planck’s Law describes?
  1. ASpectral distribution of blackbody radiation as a function of wavelength and temperature
  2. BOnly total energy
  3. COnly visible light
  4. DNo spectral distribution
Question 43Single Answer
Wien’s Displacement Law states that the wavelength of maximum radiation intensity is?
  1. AIndependent of temperature
  2. BDirectly proportional to temperature
  3. CInversely proportional to the absolute temperature
  4. DConstant
Question 44Single Answer
The solar spectrum reaching the top of the atmosphere is approximately?
  1. AOnly visible
  2. BBlackbody at 300 K
  3. CNo spectrum
  4. DBlackbody at 5772 K
Question 45Single Answer
The fraction of solar radiation in ultraviolet (UV) is approximately?
  1. A41%
  2. B50%
  3. C9%
  4. D0%
Question 46Single Answer
The fraction of solar radiation in visible range is approximately?
  1. A9%
  2. B41–44%
  3. C47%
  4. D100%
Question 47Single Answer
The fraction of solar radiation in infrared (IR) is approximately?
  1. A9%
  2. B47–50%
  3. C41%
  4. D0%
Question 48Single Answer
The solar constant (average solar irradiance at mean Earth-Sun distance) is approximately?
  1. A1000 W/m²
  2. B1361 W/m²
  3. C240 W/m²
  4. D340 W/m²
Question 49Single Answer
The average incoming solar radiation at Earth’s surface after atmospheric absorption/reflection is approximately?
  1. A1361 W/m²
  2. B240 W/m²
  3. C1000 W/m²
  4. D500 W/m²
Question 50Single Answer
Peat is the lowest rank of coal with carbon content?
  1. A=30–40%
  2. B=80–90%
  3. C=90–95%
  4. D=50–60%
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