ENVIRONMENTAL SCIENCE
PAPER – III
Note : This paper contains seventy five (75) objective type questions of two (2) marks each. All questions are compulsory.
1. For an overcast day or night, the atmosphere is
(A) stable
(B) neutral
(C) slightly stable
(D) unstable
2. Assertion (A) : The energy flow in an ecosystem follows the law of thermodynamics.
Reason (R) : The energy flow in an ecosystem is unidirectional and during the transformation of energy from one trophic level to the other, 80 – 90% of energy is lost.
Codes :
(A) Both (A) and (R) are true and (R) is the correct explanation of (A).
(B) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
(C) (A) is true, but (R) is false.
(D) (A) is false, but (R) is true.
3. Match the List – I with List – II and identify the correct answer from the given codes :
4. The environmental lapse rate during day time is governed by
(i) Wind speed
(ii) Sunlight
(iii) Topographical features
(iv) Cloud cover
The correct answer is
(A) (i) and (ii) only
(B) (ii) and (iii) only
(C) (i), (ii) and (iii) only
(D) (i) and (iv) only
5. The wavelength range of UV–C radiations is
(A) 200 – 280 nm
(B) 180 – 240 nm
(C) 320 – 400 nm
(D) 240 – 300 nm
6. In a gas chromatography experiment, the retention factor (Rf) values for pollutant ‘A’ and pollutant ‘B’ in a
mixture of pollutants were 0.5 and 0.125, respectively. If the distance travelled by solvent front is 12 cms, the
distance (in cms) travelled by pollutant ‘A’ and pollutant ‘B’ will be
(A) 6 and 1.5
(B) 3 and 1.5
(C) 0.5 and 0.125
(D) 1.5 and 3
7. Using the following equations, which can be determined correctly ?
(A) Carbon dioxide
(B) Carbonates
(C) Bicarbonates
(D) Carbonates and Bicarbonates
8. Assume that a river having dissolved oxygen 0.5 g/m3, BOD 0.3 g/m3 flowing at 80 m3/sec. converge with
another river having Dissolved Oxygen 0.7 g/m3. BOD 0.6 g/m3 flowing at a rate of 60 m3/sec. If after
the confluence the Dissolved Oxygen is 0.59 g/m3, then the BOD is
(A) 0.83 g/m3
(B) 0.43 g/m3
(C) 0.73 g/m3
(D) 0.92 g/m3
9. Cells grown in a medium containing phosphorous –32 will show radio labelling in
(A) Starch
(B) Glycogen
(C) Proteins
(D) Nucleic acids
10. C14 has a half-life of 5700 years. The fraction of the C14 atoms that decays per year is
(A) 1.216 × 10–4
(B) 0.52 × 10–3
(C) 0.78 × 10–4
(D) 2.81 × 10–4
11. Assertion (A) : Marine biodiversity tends to be highest in midlatitudes in all oceans and along coasts in the Western Pacific.
Reason (R) : Sea surface temperature along coasts in the Western Pacific is highest.
Codes :
(A) Both (A) and (R) are true and (R) is the correct explanation of (A).
(B) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
(C) (A) is true, but (R) is false.
(D) (A) is false, but (R) is true.
12. “Double digging” is a method of
(A) Bio-intensive agriculture
(B) Deforestation
(C) Aforestation
(D) Water conservation
13. The rate of replacement of species along a gradient of habitats pertains to
(A) Alpha diversity
(B) Beta diversity
(C) Gamma diversity
(D) Species diversity
14. Match the List – I and List – II. Choose the correct answer from the given codes :
15. If individuals of a species remain alive only in captivity or other human controlled conditions, the species is
said to be
(A) Ecologically extinct
(B) Mass extinct
(C) Wild extinct
(D) Anthropogenic extinct
16. Which of the following symbolises correct sequence in hydrosere ?
(A) Diatoms → Wolffia → Hydrilla → Cyperus → Populus
(B) Hydrilla → Wolffia → Cyperus → Populus → Diatoms
(C) Cyperus → Diatoms → Hydrilla → Wolffia → Populus
(D) Diatoms → Hydrilla → Wolffia → Cyperus → Populus
17. Which of the following is not a class of aquatic ecosystems based on salinity levels ?
(A) Stagnant water ecosystem
(B) Freshwater ecosystem
(C) Brackish ecosystem
(D) Marine ecosystem
18. The K-strategists are
(a) large organisms which have relatively longer life
(b) provide care for their offsprings
(c) organisms that stabilise their population at carrying capacity for the area
Choose the correct answer ;
(A) (a) and (b) only
(B) (a) and (c) only
(C) (b) and (c) only
(D) (a), (b) and (c)
19. Limnetic zone in freshwater ecosystem is characterised by
(A) Presence of rooted vegetation
(B) Absence of rooted vegetation
(C) Presence of large proportion of lime
(D) Absence of phytoplankton
20. Match the List – I with List – II, choose the correct answer from the given codes :
21. Vegetation cover shows maximum reflectance in which of the following regions of the electromagnetic
radiation spectrum ?
(A) Ultraviolet
(B) Near infrared
(C) Middle infrared
(D) Visible
22. During remote sensing of the vegetation cover, the spectral reflection of vegetation over electromagnetic radiation spectrum depends upon
(A) Pigmentation in the leaf
(B) Structure of the leaf
(C) Moisture content of the leaf
(D) All the above characters
23. Given below are statements in the context of biogeochemical cycles :
(i) Ecosystems are black boxes for many of the processes that take place within them.
(ii) Ecosystem boundaries are permeable to some degree or other.
(iii) The energy and nutrients can be transferred to and from one ecosystem to another via imports and exports.
Identify the correct answer from the codes given below :
(A) (i) & (ii) only
(B) (ii) & (iii) only
(C) (i) & (iii) only
(D) (i), (ii) and (iii)
24. The volume of ejecta and the column height for a volcano are 108.5 m3 and 24 km, respectively. What is its volcanic explosivity index value ?
(A) 2
(B) 8
(C) 7
(D) 4
25. In the context of material balance in hydrological cycle, which of the following equations is correct for oceans ?
(A) Input + change in storage = output
(B) Precipitation + inflow = evaporation
(C) Input – change in storage = output
(D) Precipitation – inflow = evaporation
26. In disaster management which steps are followed in post-disaster recovery phase ?
(A) Relief, rehabilitation, reconstruction, learning – review
(B) Risk Assessment, mitigation, preparedness, emergency plans.
(C) Relief, mitigation, emergency plans.
(D) Learning – review, emergency plans, preparedness.
27. Permafrost represents
(A) permanently frozen subsurface soil
(B) frozen leaves of Oak trees
(C) frozen needles of pine trees
(D) temporarily frozen subsurface soil
28. Assertion (A) : Estuaries are productive ecosystems.
Reason (R) : Large amounts of nutrients are introduced into the basin from the rivers that run into them.
Choose the correct answer :
(A) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(B) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
(C) (A) is true and (R) is false.
(D) (A) is false and (R) is true.
29. A confined aquifer of thickness 25 m has two wells 200 m apart along the direction of flow of water. The difference in their hydraulic heads is 1 m. If hydraulic conductivity is 50 m/day, the rate of flow of water
per day per metre of distance perpendicular to the flow of water is
(A) 25 m3/day per metre
(B) 50 m3/day per metre
(C) 5 m3/day per metre
(D) 1 m3/day per metre
30. Which of the following material has the highest hydraulic conductivity ?
(A) Clay
(B) Sandstone
(C) Limestone
(D) Quartzite
31. Which of the following energy sources is not renewable on human time scale ?
(A) Solar
(B) Hydrothermal
(C) Geothermal
(D) Biomass
32. For a solar flat plate collector the following data is given : Useful heat gain = 28 watts/m2 per hour, solar
radiation intensity = 350 watts/m2 per hour and the factor to convert beam radiation to that on the plane of the collector = 1.2. The collector efficiency is
(A) ~ 6.6 %
(B) ~ 4.8 %
(C) ~ 12.2 %
(D) ~ 15.2 %
33. For the reaction in a hydrogenoxygen fuel cell,
Given ΔG° = 240 kJ/gm – mole of H2 and Faraday’s constant = 96,500 Coulomb/gm mole.
The developed voltage in the fuel cell will be
(A) ~ 1.13 Volts
(B) ~ 2.13 Volts
(C) ~ 1.51 Volts
(D) ~ 1.24 Volts
34. Identify the correct sequence of the fuels in order of their increasing carbon intensity :
(A) Natural gas < Oil < Bituminous coal < Nuclear
(B) Oil < Coal < Natural gas < Nuclear
(C) Nuclear < Coal < Natural gas < Oil
(D) Nuclear < Natural gas < Oil < Bituminous coal
35. In nuclear thermal reactors, which of the following is not used as moderator ?
(A) Normal water
(B) Heavy water
(C) Graphite
(D) Liquid Helium
36. The minimum temperature gradient (°C/km) required for OTEC is about
(A) 20
(B) 10
(C) 40
(D) 60
37. A solar pond has electricity generating capacity of 600 MWe. If the efficiency of solar energy to electric generation process was 2% and solar energy supply rate was 300 W/m2, what is the area of solar pond ?
(A) 100 km2
(B) 90 km2
(C) 60 km2
(D) 180 km2
38. Which of the following causes warming of atmosphere but cooling of the earth’s surface ?
(A) Ozone
(B) Black carbon aerosols
(C) All Greenhouse gases
(D) Sulphates and nitrates
39. Assertion (A) : For noise level surveys in urban areas, weighting A is used for measurements.
Reason (R) : Weighting A filters out unwanted signals.
Codes :
(A) Both (A) and (R) are true and (R) is the correct explanation of (A).
(B) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
(C) (A) is true, but (R) is false.
(D) Both (A) and (R) are false.
40. Noise levels of 80 dB refers to a sound pressure level of
(A) 0.2 Pa
(B) 0.02 Pa
(C) 20 Pa
(D) 200 Pa
41. Asphyxiation is caused by
(A) HCN, COCl2
(B) NOx
(C) CHCl3
(D) AsH3
42. Sequence of a typical sewage treatment plant operation process will be
(A) Aeration → Flocculation →Sedimentation → Recarbonation → Filtration → Disinfection
(B) Aeration → Sedimentation → Flocculation → Filtration → Recarbonation → Disinfection
(C) Flocculation → Aeration → Recarbonation → Sedimentation → Filtration → Disinfection
(D) Sedimentation → Flocculation → Aeration → Filtration → Recarbonation → Disinfection
43. Which one of the following isotopes has maximum half-life period ?
(A) Rn222
(B) Pb210
(C) Ti210
(D) Bi210
44. Match the List – I with List – II and identify the correct answer from given codes :
45. Assertion (A) : Chloroflurocarbons deplete ozone.
Reason (R) : These compounds contain chlorine, bromine and fluorine.
Codes :
(A) Both (A) and (R) are true and (R) is the correct explanation of (A).
(B) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
(C) (A) is true, but (R) is false.
(D) (A) is false, but (R) is true.
46. Which of the following organic compounds is not of biogenic origin ?
(A) Isoprene
(B) α-pinene
(C) Myrcene
(D) Acrolein
47. Which of the following is used as plant indicator for detection of presence of SO2 and HF in air ?
(A) Lichen
(B) Orchid
(C) Apricot
(D) Tobacco
48. Integrated Gasification Combined Cycle (IGCC) technology is best at removing
(A) NO2 and CO
(B) CO and SO2
(C) Particulates and sulphur
(D) NO2 and SO2
49. A wastewater treatment plant in a city treats 50,000 m3 wastewater generated per day. For an average flow rate of 25 m3 per day per sq. metre, what should be the diameter of the circular primary settling tank ?
(A) 50.4 m
(B) 30.6 m
(C) 20 m
(D) 25.8 m
50. An Electrostatic Precipitator (ESP) with collector plate area = 5000 m2 treats a flue gas with drift velocity = 0.12 m/s with 98% efficiency. The volumetric flow rate (m3/s) of the flue gas is
(A) ~ 175.2
(B) ~ 213.5
(C) ~ 153.4
(D) ~ 198.9
51. Assertion (A) : Urban heat islands contribute to build up of pollutants in cities.
Reason (R) : Urban heat islands produce a somewhat stable air mass in the city’s atmosphere.
Codes :
(A) Both (A) and (R) are correct and (R) is the correct explanation of (A).
(B) Both (A) and (R) are correct, but (R) is not the correct explanation of (A).
(C) (A) is true, but (R) is false.
(D) Both (A) and (R) are false.
52. Match List – I with List – II and choose the correct answer from the codes given below :
53. A drawback of checklists is
(A) Preliminary analysis is available in scaling checklist
(B) Checklists are too general or incomplete
(C) Checklists summarises information to make it available to experts
(D) Ecosystem functions can be clearly understood from weighting methods
54. If EIUj = environmental impact units for jth alternative, EQij = environmental – quality – scale value for ith factor and jth alternative, PIUi = parameter importance units for ith factor, then what is the correct formulation for the index expressed in environmental impact units (EIUi) ?
55. Match List – I with List – II and choose the correct answer from the codes given below :
56. Risk assessment in EIA does not involve
(A) Maximum credible analysis
(B) Hazard and operability studies
(C) Preparation of disaster management plan
(D) Assessment of economic benefit arising out of a project
57. In a gravity flow autoclave, medical waste is subjected to a temperature
(A) > 120 °C
(B) < 100 °C
(C) > 300 °C
(D) > 800 °C
58. Hierarchy of priorities in hazardous waste management is
(A) Eliminate generation → Reduce generation → Recycle / Reuse → Treatment → Disposal
(B) Reduce generation → Eliminate generation → Recycle/Reuse → Treatment → Disposal
(C) Eliminate generation → Reduce generation → Treatment → Recycle/Reuse → Disposal
(D) Reduce generation → Eliminate generation → Treatment → Recycle/Reuse → Disposal
59. Public Liability Insurance Act was enacted in the year
(A) 1991
(B) 1993
(C) 1995
(D) 1997
60. Match List – I with List – II and choose the correct answer from the codes given below :
61. Match List – I with List – II and choose the correct answer from the codes given below :
62. Assertion (A) : χ2 distribution is a non-parametric distribution.
Reason (R) : χ2 is a sample statistic having no corresponding population parameter.
Codes :
(A) Both (A) and (R) are correct and (R) is the correct explanation of (A).
(B) Both (A) and (R) are correct, but (R) is not the correct explanation of (A).
(C) (A) is true, but (R) is false.
(D) Both (A) and (R) are false.
63. In a simple regression analysis of y on x, the standard error of estimate of y on x, Syx = 5, number of observations N is 30, and Σ y2 = 2000. The unexplained variance is
(A) 1500
(B) 750
(C) 500
(D) 250
64. Two normal populations have variances 
Two random samples of sizes 25 and 20, independently selected from these populations have variances of 
and 
respectively. What is the
F(24, 19) statistic ?
(A) 1
(B) 2
(C) 2.81
(D) 3.6
65. Assertion (A) : A matrix is nonsingular if and only if none of its eigen values is zero.
Reason (R) : The product of the eigen values equals the determinant of a matrix.
Codes :
(A) Both (A) and (R) are correct and (R) is the correct explanation of (A).
(B) Both (A) and (R) are correct, but (R) is not the correct explanation of (A).
(C) (A) is correct, but (R) is false.
(D) Both (A) and (R) are false.
66. In Gaussian Plume Model assume σz = cx where c is a constant and ratio of σy to σz to be a constant. If H is the effective height of the stack, the maximum concentration at a distance (x) from the stack is proportional to
(A) H–1
(B) H–2
(C) exp (–H2)
(D) H–3/2
67. The Pearson Linear correlation coefficient (r) for the following paired data (x, y) : (2, 1.4) (4, 1.8), (8, 2.1), (8, 2.3), (9, 2.6) is
(A) 0.623
(B) – 0.572
(C) 0.957
(D) 0.823
68. In a rough terrain the wind speed at a height of 10 m is 2.5 m/s. The wind speed at an elevation of 300 m will
be
(A) 4.9 m/s
(B) 1.2 m/s
(C) 3.6 m/s
(D) 7.9 m/s
69. In the context of REDD+ initiatives the land clearing in forest areas is primarily concerned with
(A) Physical resources of the area
(B) Ecology of the area
(C) Carbon budget of the area
(D) Water resources of the area
70. What was the objective of Basel Convention (1989) under UNEP ?
I. Minimize generation of hazardous wastes in terms of quantity and hazardousness
II. Disposal of hazardous wastes as close to the source of generation as possible.
III. Reduce the movement of hazardous wastes.
Choose the correct code :
(A) I and II only.
(B) II and III only.
(C) I, II and III.
(D) I only.
71. Global Warming Potential (GWP) of a greenhouse gas (GHG) is a comparison of global warming impact between
(A) 1 kg of GHG and 1 kg of methane
(B) 1 kg of GHG and 1 kg of CO2
(C) 1 kg of GHG and 1 kg of N2O
(D) 1 kg of GHG and 1 kg of CFC-11
72. Which of the following mixture of gases is called biogas ?
(A) CO2, CH4, NH3, H2S, H2O (vapour)
(B) CO, CH4, NH3, H2S, H2O (vapour)
(C) CO2, CH4, N2O, NH3, H2O (vapour)
(D) CO2, NOx, H2O, CH4
73. Environmental ethics deal with moral relationship of human beings to
(A) the value and moral status of the environment and its nonhuman contents
(B) the values that are important to development and economic growth
(C) the conservation values of selected species
(D) the development of genetically modified organisms
74. The major source of BaP (Benzo-apyrene) in atmospheric environment is
(A) residential wood burning
(B) gasoline
(C) coal tar
(D) cooked meat
75. Match the List – I with List – II and choose the correct answer from the codes given below :
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