CBSE NET Environmental Science Answer Key Paper 3 December 2015 [ CBSE NET-JRF Updates ]

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CBSE NET Paper 2 December 2015 for environmental science is given below. For complete answers and explanations visit Doorsteptutor. com - Detailed solutions and explanations to Environmental Studies Past Papers

1 Which ONE of the following statement is not true in the case of point source Gaussian Plume Model?

(1) Wind speeds arc constant in time

(2) Pollutants are conservative

(3) Rate of emission of pollutants from the stack is constant

(4) The ground level concentration is inversely proportional to effective stack height

2. Consider the simple regression equation Y = a + bX between the variables Y and X. If the standard deviation Sx and SY are 3 and 2 respectively and correlation coefficient r = 0.75, the estimate of b is

(1) 0.25 (2) 0.5 (3) 1.125 (4) 1.5

3. Consider two normal populations with variances of 10 and 20, respectively. If two Independent random samples drawn from the two populations are of the sizes 30 and 24 and their variances 10 and 15 respectively, the value of static F (29, 23) is

(1) 1.33 (2) 2.50 (3) 1.56 (4) 3.0

4. A normal population has ${\sigma }^{2}$=6. The sum of squares of deviations of 15 sample values from their mean being 120, what is the X2 (chi-square) value?

(1) 9 (2) 48 (3) 20 (4) 1.33

5. Choose the correct sequence of phases associated with a population growth that exhibits logistic model represented by$\frac{dN}{dt}=rN\left(1-\frac{N}{k}$)

(1) $Stationaryphase\to Exponentialphase\to Lagphase$

(2$\right)Lagphase\to Stationaryphase\to Exponentialphase$

(3) $Lagphase\to Exponentialphase\to Stationaryphase$

(4) $Exponentialphase\to Stationaryphase\to Lagphase$

6. The toxic substances of special concern emitted during incineration process from waste to energy plants are

(a) Carbon monoxide (b) Carbon di oxide (c) dioxins (d) Furans

(1) (a) and (b) only

(2) (b) and (c) only

(3) (a) and (d) only

(4) (c) and (d) only

7. Sanitary landfills have following properties. They

(a) Reduce trash volume in a short time

(b) Release CH4 and CO2

(c) Eventually produce leachate which contaminant ground water

(1) (a) and (b) only

(2) (b) only

(3) (a) and (c) only

(4) (a), (b) and (C)

8. For providing information related to environment to decision makers, policy makers, scientists and environmental engineers all over the country, ENVlS was established in the year belonging to:

(1) Sixties (2) Seventies (3) Eighties (4) Nineties

9. The total radioactive forcing of all major and minor greenhouse gases in the year 2014 is estimated to be:

(1) $~$ 2.51 W/m2 (2) ~ 2.93 W/m2 (3) ~ 1.87 W/m2 (4) ~ 7 W/m2

10. For the range of temperature observed in the earth’s atmosphere, the saturation-mixing ratio (Ws) and the total pressure are related as:

(1) Ws$\propto \frac{1}{P}$ (2) Ws$\propto$ p (3) Ws$\propto {P}^{\frac{3}{2}}$ (4) Ws$\propto {P}^{-\frac{3}{2}}$

11. A thermal power plant based on coal produces 100 MW of electrical power with conversion efficiency of 30%. If the ash content of coal is 5 % and net heating value is 30MJ per kg, how much ash is produce daily.

(1) 48 metric tons (2) 24 metric tons (3) 90 Metric tons (4) 60 metric tons

12. Under which section of Wildlife (Protection) Act 1972, the state government can declare an area closed to hunting for a specified period

(1) Section 35 (2) Section 27 (3) Section 38- A (4) Section 37

13. Which one of the following criteria should not contribute to the process of establishing Significance of the impact of a developmental project on environment?

(1) Sensitivity of surrounding environment

(2) Probability of the impact occurring

(3) Views and values of the developer

(4) Views and suggestions of the public

14. The following benefits may accrue as a result of environmental audit.

(a) Material audit leads to improvement in the production efficiency and cost

(b) Pollution monitoring leads to environmental quality improvement

(c) Approach towards zero discharge and zero emission leads to clean development

(d) Incentive for pollution abatement in the form of reduction in import tax leads to cleaner environment

(1) (a) only

(2) (b) and (c) only

(3) (b) and (d) only

(4) (a), (b), (c) and (ii)

15. Environmental Impact Assessment (EIA) was Incorporated under Which one of the following legislations?

(1) Air (Prevention and Control of Pollution) Act 1981

(2) Wildlife (Protection) Act, 1981

(3) Indian Forest Act, 1927

(4) Environmental (Protection) Act l986

16. A company operating vehicle-manufacturing plant has developed Environmental Management System (EMS) to enhance its performance and to improve quality of its products. The key aspects of this EMS would include

(1) Audit of manufacturing plant safety procedure

(2) Maximizing returns to stakeholders of the company

(3) The development of an overall framework for environmental affairs of the company

(4) The aspects of costs involved in developing an environmental policy.

17. Best practice in scoping requires

(a) A site visit

(b) Relevant experience of other similar developmental projects

(c) Employing formal scoping techniques

(1) (a) only (2) (a) and (b) only

(3) (b) and (c) only (4) (a) (b) and (c)

18. Match the List- I and List - II. Identify the correct answer from the codes given below

Codes-

(a) (b) (c) (d)

(1) (iv) (iii) (ii) (I)

(2) (i) (iv) (iii) (ii)

(3) (ii) (i) (iv) (iii)

(4) (iii) (ii) (i) (iv)

19. The decision making process in EIA generally does not include:

(1) Cost - benefit analysis (2) Procedural information

(3) Socio - economic aspects (4) Operational management

20. Which of the following actions may be recommended for acidified lakes?

(1) Ammoniation (2 Liming (3) Ozonation (4) Chlorination

21. Given below are two statements. One labelled as Assertion (A) and the other labelled as Reason (R).

Assertion (A) - All types of aerosols contribute to radiative forcing

Reason- (R) -Aerosol effectively absorb electromagnetic radiations

(1) Both (A) and (R) are correct and (R) is the correct explanation of (A)

(2) Both (A) and (R) are correct and (R) is not the correct explanation of (A)

(3) (A) is true, but (R) is false

(4) (A) is false, but (R) is true

22. Given below are two statements. One labelled as Assertion (A) and the other labelled as Reason (R):

Assertion (A): The efficiency of fuel cells is not limited by the second law of thermodynamics

Reason (R): There is no intermediate heat to work conversion in a fuel cell

(1) Both (A) and (R) are corrected and (R) is the correct explanation of (A)

(2) Both (A) and (R) are correct and (R) is not the correct explanation of (A)

(3) (A) is true, but (R) is false

(4. ) (A) is false, but (R) is true.

23. Given below are two statements. One labelled as Assertion (A) and the other labelled as Reason (R)

Assertion (A): A wind rose with approximately equal length spoke (or petals) represents great variation of wind direction over a given duration

Reason (R): The length of the spokes is a measure of wind speeds in a given duration

(1) Both (A) and (R) are corrected and (R) is the correct explanation of (A)

(2) Both (A) and (R) are correct and (R) is not the correct explanation of (A)

(3) (A) is true, but (R) is false

(4. ) (A) is false, but (R) is true

24. Given below are two statements. One labelled as Assertion (A) and the other labelled as Reason (R)

Assertion (A): Large-scale OTEC development may exacerbate the greenhouse effect.

Reason (R): Methane is a greenhouse gas.

(1) Both (A) and (R) are corrected and (R) is the correct explanation of (A)

(2) Both (A) and (R) are correct and (R) is not the correct explanation of (A)

(3) (A) is true, but (R) is false

(4. ) (A) is false, but (R) is true

25. in a spectrophometric cell of 2.0 cm path length, the solution of a substance shows the absorbance value of 1.0. If the molar absorptivity of the compound is 2$×{10}^{4}L{mol}^{-1}$ calculate the concentration of substance in solution. What is the concentration of the substance in that solution?

(1) $2.5×{10}^{-5}mol{L}^{-1}$

(2) $4.0×{10}^{-4}mol{L}^{-1}$

(3) $1.0×{10}^{4}mol{L}^{-1}$

(4) $5.0×{10}^{-4}mol{L}^{-1}$

26. In order to obtain useful fusion energy from a thermonuclear fusion reactor, If the confinement time of the D + T Plasma ions is 1$\mu$ sec, the ion density (per m3) must be

(1) $\ge {10}^{26}{m}^{-3}$

(2) $\ge {10}^{23}{m}^{-3}$

(3) $\ge {10}^{20}{m}^{-3}$

(4) $\ge {10}^{14}{m}^{-3}$

27. Which of the following is not a detrivore?

(1) Vultures. (2) Earthworms (3) Insects (4) Hydrilla

28. Secondary succession begins at:

(1) Base rock (2) newly cooled lava

(3) Burnt forest (4) newly created shallow pond

29. Given below are two statements. One labelled as Assertion (A) and the other labelled as Reason (R):

Assertion (A): It is generally agreed that life on earth began between 3.5 and 4.5 billion years ago.

Reason (R): The first form of life was the anaerobic bacteria as environment was devoid of oxygen.

(1) Both (A) arid (R) are correct and (R) is the correct explanation of (A).

(2) Both (A) and (R) are correct and (R) is not the correct explanation of (A).

(3) (A) is true, but (R) is false.

(4) (A) is false, but (R) as true.

30. The total number of Sustainable Development Goals (SDGs) announced by UN in 2015 are:

(1) 15 (2) 17 (3) 19 (4) 21

31. The total area of productive ecosystem required to support the population sustainably is known as:

(1) Ecological footprint (2) Ecological handprint

(3) Carrying capacity (4) Ecological services

32. Carrying capacity of a population determines that a particular habitat for a given species can sustain

(1) Minimum Population

(2) Maximum Population

(3) Average Population

(4) A fraction of migrating population

33. Which one of the following is the most productive ecosystem?

(1) Lakes and stream

(2) Estuaries

(3) Continental shelf

(4) Open ocean

34. A measure that combines the number of species and their relative abundance compared with one another is termed

(1) Species richness (2) Species evenness

(3) Species diversity (4) Species relationships

35. The figures of humanity’s global footprint (million hectares) for different countries estimated by WWF and Global Footprint Network in 2008 fall in the sequence

(1) $US>China>EuropeanUnion>Japan>India$

(2) $China>US>Japan>India>EuropeanUnion$

(3) $EuropeanUnion>US>China>japan>India$

(4) $US>EuropeanUnion>China>India>Japan$

36. A common features of the synoptic and mesoscale motions in the atmosphere is that their

(1) Vertical motion component is more in magnitude than the horizontal wind component

(2) Vertical motion component is roughly comparable to horizontal wind component.

(3) Vertical motion Component is an order of magnitude smaller than the horizontal wind Component.

(4) Properties can be studied by conventional synoptic networks.

37. The shape of a plume from a tall stack located on a flat terrain is found to be of “fanning” type. It implies that the atmosphere is under the condition of:

(1) Strong lapse rate (2) Weak lapse rate

(3) Inversion (4) Weak lapse rate below inversion

38. Given below are two statements. One labelled as Assertion (A) and the other labelled as Reason (R):

Assertion (A) - Thunderstorm is a violent convective event accompanied by thunder and lightening

Reason (R) - Thunderstorm is not associated with vertical air movement, humidity and instability

(1) Both (A) and (R) are correct and (R) is the correct explanation of (A).

(2) Both (A) and (R) are correct and (R) is not the correct explanation of (A).

(3) (A) is true, but (R) is false.

(4) (A) is false, but (R) as true.

39. According to National Ambient Air Quality Standards in India, the permissible 24-hour average concentration of lead in ambient air of an industrial area is:

(1) $1.0\mu g/{m}^{3}$

(2) $2.0\mu g/{m}^{3}$

(3) $3.03\mu g/{m}^{3}$

(4) $4.0\mu g/{m}^{3}$

40. Peat soils, which have undergone prolonged drought in the forest are prone for:

(a) Ground forest fire

(b) Underground forest fire

(c) Tree Crown fare

Choose the correct code:

(1) (a) only

(2) (b) only

(3) (a) and (b) only

(4) (a), (b) and (c)

41. Insect pests can be controlled by the use of:

(a) Insecticide (b) Pheromones

(c) Juvenile Hormones (d) Nitro phosphate

(1). (a) only

(2) (a) and (b) only

(3) (a), (b) and (c) only

(4) (a), (b). (c) and (d)

42. Dioxins and Furans are two toxic gaseous pollutants, which can be measured by:

(1) GC –MS (2) TLC (3) ICP - AES (4) AAS

43. Based on the pE value for four water samples given below, the concentration of dissolved oxygen shall be highest in:

(1) pE = —4.1

(2) pE = 13.9

(3) PE = 1.0

(4) pE = 7.0

44. A total of 10 instantaneous sound pressure level measurement at 10 sec intervals for a traffic site are given in the table below

 S. No 1 2 3 4 5 6 7 8 9 10 SPL (dB) 71 75 70 78 80 84 76 74 75 74

The estimated L90 from these measurements is-

(1) $~71dB$

(2) ~70dB

(3) ~74dB

(4) ~75dB

45. The composition of rhizospheric, microorganisms are dependent on the soil

(a) Texture (b) Organic matter (c) pH (d) Elasticity

(1) (a) only

(2) (a) and (b) only

(3) (a), (b) and (c) Only

(4) (a), (b), (c) and (d)

46. Given below are two statement. One Labelled as Assertion (A) and the other labeled as Reason (R):

Assertion (A): The fundamental goal of a dose-Response assessment is to obtain mathematical relationship between the amount of a toxicant that a human is exposed to and the risk that there will be.

Reason (R); To apply dose- response data obtained From animal bioassay to humans, a scaling factor must be introduced.

(1) Both (A) and (R) are correct and (R) is the correct explanation of (A)

(2) Both (A) and (R) are correct and (R) is not the correct explanation of (A)

(3) (A) is true, but (R) is false

(4) (A) is false, but (R) is true.

47. Tropical grasslands with scattered trees are also known as

(1) Taigas (2) Steppe (3) Savannas (4) Meadows

48. On 18th April 2015, Global Alliance to Eliminate Lead Paint (GAELP) announced the goal of eliminating lead paint around the world by

(1) 2020 (2) 2025 (3) 2028 (4) 2022

49. The form of coal/fuel in the ascending order of heating value can be best represented as

(1) $Lignite

(2) $Bituminous

(3) $Peat

(4) $Peat

50. In India wetland conservation is presently done by the Ministry of Environment, Forest and Climate change under

(1) National wetland conservation programme

(2) National plan for conservation of Aquatic Ecosystem

(3) National Lake Conservation Programme

(4) Coastal Regulation Zone

51. Soil salination is not caused by

(1) Agricultural area with high ground water irrigation

(2) Coastal swampy area

(3) Flood prone area

(4) Upland lateritic area with wastewater irrigation

52. Ground water occurs under

(a) Unconfined condition in shallow aquifers

(b) Semi Confined aquifers

(c) Confined aquifers

(1) (a) only

(2) (a) and b) only

(3) (b) and (c) only

(4) (a) (b) and (c)

53. DEM (Digital Elevation Model) is best represented using:

(1) Vector Data Models (2) Raster Data Models

(3) Coverage Data Structure (4) Non-topological Data Structure

54. Delta are classified into six basic types taking cognissance and importance of

(a) Rivers (b) Waves (c) Tides

(1) (a) only (2) (a) and (b) only (3) (a) and (c) only (4) (a), (b) and (c)

55. Large elongated depression with steep walls formed by the downward displacement of a block of the earth surface between nearly parallel faults systems

(1) Thrust faults

(2) Horst

(3) Grabben

(4) Rift valley

56. Which form of scattering in visible region in the atmosphere is not dependent on wavelength?

(a) Rayleigh (b) Mie (c) Non-selective

(1) (a) only (2) (a) and (b) only (3) (c) only (4) (b) and (c) only

57. Best spatial configuration for designing a core natural area is:

(1) Circular (2) Rectangular (3) Square (4) Triangle

58. Ecosystem resilience is the capacity of an ecosystem to sustain its:

(a) Fundamental function

(b) Structure

(c) Feedbacks in the face of a spectrum of shock and perturbations

(1) (a) and (b) only (2) (b) and (c) only (3) (a) and (c) only (4) (a), (b) and (c)

59. With regard to ozone depletion over Antarctica, select the false statement -

(1) Circumpolar vortex acts as a reaction chamber

(2) Polar Stratospheric Clouds (PSCs) are formed within the vortex

(3. ) There is very low temperature inside the vortex

(4) The heterogeneous reaction

CIONO2 (s) + HCl (g) →Cl2 (g) +HNO3 (s) takes over PSCs

60. Match the Lists - I and - II choose the correct answer from the codes given below

Codes:

(a) (b) (c) (d)

(1) (lv) (ii) (iii) (I)

(2) (j) (iii) (iv) (ii)

(3) (ii) (1v) (i) (iii)

(4) (iii) (i) (ii) (iv)

61. A laboratory analysis of a waste water sample indicated BOD of 750mg L-1 with rate constant (K) 0.20 day -1 at 20 $°$ C. The 5-day BOD at 20°C is

(1) 675 mg L-1

(2) 650 mg L-1

(3) 400 mg L-1

(4) 600mg L-1

62. A stream with a flow of 0.2 m3/sec and a chloride concentration of 50mg/L receives a discharge of mine drainage water with a flow of 0.05m3/sec and chloride concentration of 1500mg/L. The downstream concentration of chloride is

(1) 150mg/L

(2) 200mg/L

(3) 340mg/L

(4) 380mg/L

63. Four students (list A) working independently in a chromatographic analysis (list B) reported the Retention Factor (Rf) values-

The result of which student (s) is (are) definitely incorrect

(1) R and U (2) S and T (3) S, T and U (4) T

64. The mechanism of the formation of gaseous N2O5 from NO2, and O2, gases in the gas phase within clouds is:

$N{O}_{2}\left(g\right)+{O}_{3}\left(g\right)—N{O}_{3}\left(g\right)+{O}_{2}\left(g\right)$ (I)

$N{O}_{3}\left(g\right)+N{O}_{2}\left(g\right)—{N}_{2}{O}_{5}\left(g\right)$ (ii)

The experimentally determined rate law is

—d [N02 (g) ] /dt

= K [N02 (g) ] [03 (g) ]

Based on the information provided which of the following statement is incorrect

(1) Overall reaction is: 2N0 (g) +03 (g) —N205 (g) + 02 (g)

(2) The reaction intermediate is NO3

(3) The rate-determining step is reaction (i)

(4) The rate reaction (ii) is slower than the rate of reaction (i)

65. In a rain water sample of pH = 8.45, the dominant species of dissolved sulphur dioxide shall be

(1) SO2. H2O (2) HS${O}_{3}^{-}$ (3) S ${O}_{3}^{2-}$ (4) ${S}_{2}{O}_{5}^{2-}$

66. An aquifer of sand has a saturated column of cross – sectional area 0.2x5 m and a depth of 3 m. If the specific yield of sand is 25%, how much water can be extracted from the aquifer.

(1) 0.5 m3 (2) 0.75 m3 (3) 1.2 m3 (4) 1.5 m3

67. Atmospheric life times of CFCs is typically in the range:

(1) 50 - 102 years (2) 140 - 200 years (3) 200 - 400 years (4) 152 – 210years

68. With respect to CO2, Global Warming potential (GWP) for N20 Over a time horizon of 100 years is estimated to be:

(1) 156

(2) 210

(3) 296

(4) 240

69. The greenhouse gas N2O strongly absorbs infrared radiations of wavelength (s)

(1) ~45$\mu$ m (2) $~$7.8 μ m and 8.6 μ m

(3) ~9.6 μ m (4) ~10.6 μ m

70. By the year 2022, Indian government has set a new target of Solar Power generation of

(1) 4 GW (2) 60 GW (3) 75 GW (4) 100 GW

71. Match the Lists - 1 and - II. Identify the correct answer from the codes given below the Lists.

List — I List - II

(Causes) (Effects)

(a) Soil organisms (I) Algal bloom

(b) Phosphorous assimilation (ii) Chronic obstructive pulmonary diseases

(c) Water pollution (iii) Decomposition

(d) Air pollution (iv) Complexing agent

Codes:

(a) (b) (c) (d)

(1) (i) (ii) (iii) (iv)

(2) (iii) (iv) (i) (ii)

(3) (ii) (iii) (iv) (j)

(4) (iv) (ii) (I) (iii)

72. The wavelengths that are most important in the context of stratospheric ozone depletion are-

(1) 280 - 320nm (2) 400 - 700nm (3) 700 - 900nm (4) $>$ 900nm

73. Remote sensing satellites such as RESOURCESAT are usually placed in polar-

(a) Low earth polar orbit

(b) Sunsynchromous orbit

(c) Geosynchronous orbit

Codes:

(1) (b) And (c) only

(2) (a) and (b) only

(3) (a) and (c) only

(4) (a), (b) and (c)

74. Gills of marine fishes perform the functions of the following

(1) Water loss, and salt excretion

(2) Water gain and salt excretion

(3) Water uptake and solute uptake

(4) Water loss and solute uptake

75. The instrument used for determination of soil water loss by percolation, evaporation and runoff is called

(1) Lysimeter

(2) Rain Gauze

(3) Soil moisture meter

(4) Soil porosity nicker