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# CBSE NET Environmental-Science December-2012 Solved Paper III Download All the Papers to Prepare for NET 2022

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1. In a multiple regression model, the f-ratio is used to test the

(A) Variance of the data

(B) Standard error of mean

(C) R2 value

(D) Overall goodness of fit of the model.

2. If the mean of a sample is 20, the standard error of mean is 1 and the t-statistic for 95 % level of confidence is 2.5, the population mean will be in the range

(A) 17.5 to 22.5

(B) 15 to 25

(C) 20 to 25

(D) 15 to 20

3. The third moment about the mean of a distribution of a set of observations is a measure of

(A) Mode

(B) Skewness

(C) Kurtosis

(D) Variance

4. Consider an air shed over a city in the form of a rectangular box. The wind velocity is 5 m/sec normal to left face of the box. The length of the box along the direction of wind is 10 km and mixing height is 1 km. assuming rapid mixing of the pollutants which are conservative in nature, the concentration of the pollutants in the city would reach 63 % of its final value in

(A) 2,000 sec

(B) 5,000 sec

(C) 10,000 sec

(D) 1,000 sec

5. Which one of the following states of mercury is volatile?

(A) Organic

(B) Ionic

(C) Atomic

(D) All of the above

6. Molar extinction coefficient of H2O2 at 240 nm is 0.04 M β 1 cm β 1. The concentration of H2O2 in a solution which has absorbance of 0.6 in a 3 cm curette will be

(A) 5 M

(B) 10 M

(C) 15 M

(D) 20 M

8. Which one of the following is a peroxyl radical?

(A) OH0

(B) R0

(C) RO0

(D) ROO0

9. Depending upon the amount of net primary productivity the various ecosystems can be arranged in a decreasing sequence of yield.

(A) Tropical seasonal forest β Tropical rain forest β Temperate Grassland β Woodland and Shrubland.

(B) Tropical seasonal forest β Tropical rain forest β Woodland and Shrubland β Temperate Grassland

(C) Tropical rain forest β Temperate Grassland β Woodland and Shrubland β Tropical seasonal forest.

(D) Tropical rain forest β Tropical seasonal forest β Woodland and Shrubland β Temperate Grassland.

10. Which of the following is a correct sequence of secondary seral vegetation development on any habitat?

(A) Ecesis β Invasion β Aggregation β Stabilization

(B) Ecesis β Aggregation β Invasion β Stabilization

(C) Aggregation β Invasion β Ecesis β Stabilization

(D) Invasion β Ecesis β Aggregation β Stabilization

11. What is common feature among the following?

Abiesdelavayi

Aconitum diennorrhzum

Aglaiaperviridis

(A) All have been extinct.

(B) All are gymnosperms.

(C) All are identified as endangered species.

(D) All are angiosperms.

12. RaunkiaerΥs normal biological spectrum for phanerogamic flora of the world exhibits one of the following sequences of occurrence (%) of different life forms.

(A) Phanerophytes, Hemicryptophytes, Therophytes, Cryptophytic, Chamerophytes.

(B) Phanerophytes, Hemicryptophytes, Therophytes, Chamerophytes, Cryptophytic.

(C) Phanerophytes, Hemicryptophytes, Cryptophytic, Chamerophytes, Therophytes.

(D) Phanerophytes, Chamerophytes, Hemicryptophytes, Cryptophytic, Therophytes.

13. One of the following categories of earthworms is most suitable for wasteland reclamation.

(A) Epigeic

(B) Anecic

(C) Endogeic

(D) None of the above

14. How many mega-bio-diverse countries have been identified in the world?

(A) 2

(B) 12

(C) 17

(D) 35

15. Which one of the following is an Exist method of biodiversity conservation?

(A) Seed storage

(B) DNA Bank

(C) Tissue culture

(D) All the above

16. Which one of the following is a methyl isocyanate (MIC) based pesticide?

(A) Sevin (Carbaryl)

(B) Temix (Aldicarb)

(D) All the above

17. The sequence of fossil fuels in the order of higher to lower heating value is as follows:

(A) Coal, Petroleum, Natural Gas, Hydrogen.

(B) Hydrogen, Natural Gas, Petroleum, Coal.

(C) Hydrogen, Coal, Natural Gas, Petroleum.

(D) Natural Gas, Petroleum, Coal, Hydrogen.

18. Natural ore of radioactive materials does not contain which one of the following isotope?

(A) U235

(B) Pu239

(C) U238

(D) Th232

19. The process of splitting bigger hydrocarboninto smaller hydrocarbon molecules is called

(A) Pyrolysis

(B) Thermal decomposition

(C) Cracking

(D) Combustion

20. Which one of the following is a complex in organic fertilizer?

(A) Urea

(B) Super phosphate

(C) Potash

(D) NPK

21. The sequence of ease of decomposition of organic compounds in soil is

(A) Lignin β Hemicellulose β Starch β Crude protein β Fat

(B) Crude protein β Starch β Fat β Lignin β Hemicellulose

(C) Starch β Crude protein β Hemicellulose β Fat β Lignin

(D) Fat β Starch β Lignin β Hemicellulose β Crude protein

22. Which one of the following radionuclides has the lowest half-life period?

(A) C14

(B) Sr90

(C) I131

(D) Cs137

23. Match the rules mentioned in Column β I with year of enforcement mentioned in Column β II.

Column β I Column β II

a. Hazardous Wastes (Management and Handling) Rules 1.2000

b. Biomedical Solid Wastes (Management and Handling) Rules. 2.1978

c. Municipal Solid Wastes (Management and Handling) Rules 3.1989

d. The Water (Prevention and Control of Pollution) Cess Rules 4.1998

Choose the correct code:

Codes:

a b c d

(A) 3 4 1 2

(B) 4 1 2 3

(C) 2 4 3 1

(D) 1 3 4 2

24. Average composition of biodegradable waste in Municipal Solid Waste (MSW) of India is

(A) 30 β 35 %

(B) 40 β 45 %

(C) 55 β 65 %

(D) 60 β 70 %

25. The treatment method recommended for the human anatomical waste generated from hospitals is

(A) Chemical disinfection

(B) Autoclaving

(C) Incineration

(D) All the above

26. Match the waste class mentioned in Column β I with Color Code of the Collection Container mentioned in Column β II.

Column β I Column β II

List I

a. Human Anatomical Waste

b. Waste Scrap

d. Disposable plastics

List II

1. Blue

2. Green

3. Red

4. White

Choose the correct code:

Codes:

a b c d

(A) 2 3 1 4

(B) 4 2 3 1

(C) 1 2 3 4

(D) 3 1 4 2

27. Which of the following is true when frequency of occurrence of risk is remote but possible?

(A) Risk is acceptable.

(B) Risk reduction measures should be implemented.

(C) Risk is unacceptable.

(D) Both (A) and (B) are true.

28. Given below are two statements, one labelled as Assertion (A) and the other labelled as Reason (R) .

Assertion (A) : Indirect impacts are more difficult to measure, but can ultimately be more important.

Reason (R) : In areas where wildlife is plentiful, such as Africa, new roads often lead to the rapid depletion of animals.

Codes:

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

(B) Both (A) and (R) are true, but (R) is not the correct explanation.

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

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

29. An earthquake measuring over 8 on Richter scale is rated as

(A) Destructive

(B) Major

(C) Great

(D) Damaging

30. Given below are two statements, one labelled as Assertion (A) and the other labelled as Reason (R) .

Assertion (A) : It is difficult to judge how changes in localized gas samples represent more general conditions in the Volcano.

Reason (R) : The composition of the juvenile gases emitted from volcanic vents often show considerable variation over short periods and distances.

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.

31. In a false β color set, human visual perception is limited to how many independent coordinates?

(A) Three

(B) Four

(C) One

(D) Five

32. If D = Detector Dimension, F = Focal Length, H = Flying Height, then Ground Resolution Element (GRE) is equal to

(A) (D/F) X H

(B) D/F

(C) H/F

(D) D/H

33. Darkest level of the associated color (RGB) would have brightness value equal to

(A) 0

(B) 256

(C) 255

(D) 2047

35. Match the List β I with List β II and choose the correct answer from the codes given below:

List β I List β II

(Constituents of Particulate matter) (Sources)

List I

a. Si

b. PAH

c. SO2 - 4

d. Pb

List II

1. Natural Resources

2. Incomplete combustion of fossil fuels.

3. Elements largely introduced by Human Activities.

4. Reactions of a gas in atmosphere.

Choose the correct code:

Codes:

a b c d

(A) 1 2 4 3

(B) 2 3 4 1

(C) 2 4 1 3

(D) 3 4 2 1

37. Scale lengths associated with synoptic scale phenomenon in atmosphere are typically in the range

(A) 10 β 100 km

(B) 200 β 40,000 km

(C) 10,000 β 100,000 km

(D) 1 β 10 km

38. Assume that the atmosphere is isothermal at 25 deg; C and the estimated maximum daily surface temperature is 35deg; C, the mixing height is (take adiabatic lapse rate to be 1 deg; C per 100 m)

(A) 3.5 km

(B) 2.5 km

(C) 1.5 km

(D) 1 km

39. The wavelengths of UV-A radiations are in the range

(A) 200 β 240 nm

(B) 240 β 280 nm

(C) 280 β 320 nm

(D) 320 β 400 nm

40. Two sounds of 80 dB and 85 Db superimpose at a location. What is the resultant sound at that location?

(A) Download all the papers to prepare for NET 2022 ~Explanations at doorsteptutor. com: 82 dB

(B) Download all the papers to prepare for NET 2022 ~Explanations at doorsteptutor. com: 87 dB

(C) Download all the papers to prepare for NET 2022 ~Explanations at doorsteptutor. com: 91 dB

(D) Download all the papers to prepare for NET 2022 ~Explanations at doorsteptutor. com: 165 dB

41. The coefficient of performance of a wind turbine for maximum power output is

(A) 13/18

(B) 5/8

(C) 16/27

(D) 11/17

42. Which of the following does not have a direct role in climate change?

(A) Sulphate and nitrate aerosols

(B) Black carbon aerosols

(C) Surface ozone

(D) Nitric oxide

43. Which method is used to separate molecules on the basis of their sizes?

(A) Ion exchange chromatography

(B) Molecular exclusion chromatography

(D) Thin layer chromatography

44. Which type of support media is used in different types of electrophoresis?

(A) Agarose gel

(B) Polyacrylamide gel

(C) Sodium dodecyl sulphate polyacrylamide gel

(D) All the above

45. Which of the following categories of plants get benefitted more due to elevation of CO2 level?

(A) C3 plants

(B) C4 plants

(C) CAM plants

(D) All of the above

46. Aquifers that extend continuously from the land surface through material of high permeability are

(A) Aquitards

(B) Auicludes

(C) Confined aquifers

(D) Unconfined aquifers

47. Which one of the following is used to determine ambient concentration of suspended particulate matter?

(C) Sacchi Disk

(D) Folin-Wu method

48. Which of the following laws states that the solubility of a gas in a liquid is proportional to the partial pressure of that gas in contact with liquid?

(A) HickΥs law

(B) HenryΥs law

(C) Hardy-Weinberg law of equilibrium

(D) 2nd Law of Newton

49. Maximum CaO is found in

(A) Bauxite

(B) Limonite

(C) Lime Stone

(D) Siderite

50. The sequence of chemical constituents in order of their abundance in a majority of sedimentary rocks is

(A) SiO2 > TiO2 > Al2O3 > Fe2O3

(B) SiO2 > Al2O3 > Fe2O3 > TiO2

(C) SiO2 > Fe2O3 > Al2O3 > TiO2

(D) SiO2 > Fe2O3 > TiO2 > Al2O3

51. The primary producers in the marine ecosystem are

(A) Eubacteria and Algae

(B) Cyanobacteria and Algae

(C) Algae and Protozoans

(D) All of the above

52. Mycorrhizae can be used as bio fertilizers because they

(A) Fix nitrogen

(B) Fix CO2

(C) Solubilize phosphate

(D) Kill pathogens

53. Given below are two statements, one labelled as Assertion (A) and the other labelled as Reason (R) .

Assertion (A) : Some plants with mycorrhizal fungi are able to occupy habitats that otherwise could not inhabit.

Reason (R) : The importance of mycorrhizal plant interaction is attested by the fact that 95 % of all plants have mycorrhizae.

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.

54. An interactive association between two populations in which one population benefits from the association, while the other is not affected, is

(A) Mutualism

(B) Neutralism

(C) Commensalism

(D) Symbiosis

55. The method for down streaming of ethanol from fermentation broth is

(A) Filtration

(B) Flow cytometry

(C) Distillation

(D) Flame Photometry

56. The country which uses maximum nuclear power is

(A) U. S. A.

(B) Japan

(C) France

(D) Germany

57. Which bacteria removes copper from low grade copper ore?

(A) Thiobacillussp

(B) Bacillus thuringiensis

(C) Rhizobium sp

(D) All of the above

58. Which of the following is not a part of Geographic Information System (GIS) ?

(A) Projection

(B) Overlay

(C) Reclassification

(D) Measuring distance and connectivity

59. Ultrafiltration can remove

(A) Suspended solids

(B) Bacteria

(C) Protozoa

(D) All the above

60. A good automobile fuel, in addition to having high calorific value, should have

(A) High ignition temperature

(B) High viscosity

(C) Low ignition temperature

(D) Moderate ignition temperature

61. Reserve food material in algae is

(A) Starch

(B) Cellulose

(C) Protein

(D) None of the above

62. The biodegradability of xenobiotics can be characterized by

(A) Rate of CO2 formation

(B) Rate of O2 consumption

(C) Ratio of BOD to COD

(D) All of the above

63. The soil borne plant pathogens could be controlled by

(A) Lowering pH

(B) Increasing pH

(D) All of the above

64. A selective Lignin degrading fungus belongs to

(A) Soft β rot

(B) Brown β rot

(C) White β rot

(D) Red β rot

65. The drastic reduction in the number of intestinal pathogens during activated sludge process is the overall result of

(A) Competition

(D) Competition, adsorption, predation and settling

66. Which of the following disinfection method does not result in synthesis of organochlorine?

(A) Chlorination

(B) Chloroamination

(C) Ozonation

(D) None of the above

67. An organismΥs niche is

(A) The way the organism uses the range of physical and biological conditions in which it lives.

(B) All the biological and physical factors in the organismΥs environment.

(C) The function role played by the organism where it lives.

(D) The range of temperature that the organism needs to live.

68. The pyramid of biomass is invented in

(A) Forest ecosystem

(B) Greenland ecosystem

(C) Aquatic ecosystem

(D) All of the above

69. Which of the following chemicals of anthropogenic origin mimics the effect of estrogen in animals?

(A) Alkyl phenol

(B) Polychlorinated biphenyl

(C) O, p β² - DDT

(D) All the above

70. βBlack Footβ disease in human beings caused due to use of water contaminated with

(A) Mercury

(C) Silver

(D) Arsenic

71. Largest amount of fresh water is present in

(A) Lakes

(B) Rivers

(C) Glaciers

(D) Polar Ice

72. A threatened species is

(A) Only endangered species

(B) Only vulnerable species

(C) Only rare species

(D) all of the above

73. Given below are two statements, one labelled as Assertion (A) and the other labelled as Reason (R) .

Assertion (A) : Animals adopt various strategies to survive in hostile environment.

Reason (R) : Praying mantis is green in color which emerges with plant foliage.

Choose the correct code:

Codes:

(A) Both (A) and (R) are true, with (R) being the correct explanation of (A) .

(B) Both (A) and (R) are true but (R) is not correct explanation of (A) .

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

(D) Both (A) and (R) are false.

74. Given below are two statements, one labelled as Assertion (A) and the other labelled as Reason (R) .

Assertion (A) : Increasing temperature in the environment influences gonadal growth in fish.

Reason (R) : Increase in day length causes increase in environmental temperature in summer.

Choose the correct code:

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, and (R) is wrong.

(D) (A) and (R) are wrong.

75. Match Column β I with Column β II:

Column β I Column β II

a. The Rio Summit 1.1997

b. Johannesburg Earth Summit 2.1972

c. Kyoto Protocol 3.1992

d. The Stockholm Conference 4.2002

Codes:

a b c d

(A) 3 4 1 2

(B) 1 2 3 4

(C) 4 3 2 1

(D) 2 1 4 3