UGC NTA NET/JRF Exam, Environmental Sciences, June-2020

Total Questions: 100

71. Match List-I (Atmospheric stability) with List-II (Lapse Rate).

List-I (Atmospheric stability)List-II (Lapse Rate)
(a) Absolutely Stable(i) ELR = DALR
(b) Absolutely Unstable(ii) ELR < DALR
(c) Conditionally Unstable(iii) ELR > DALR
(d) Dry Neutral(iv) SALR < ELR < DALR

Choose the correct answer from the options given below.
Codes:

Option(a)(b)(c)(d)
A(ii)(iii)(i)(iv)
B(ii)(iii)(iv)(i)
C(iii)(ii)(iv)(i)
D(iii)(ii)(i)(iv)
Correct Answer: В.
Solution:

The ELR (Environmental Lapse Rate) is the actual rate at which the ambient temperature changes with height. If no heat is exchanged with the surrounding air during this process, which is called "adiabatic cooling", the rate at which the air cools, the Adiabatic Lapse Rate (ALR) is a constant.
Stable - ELR less than DALR
• ELR < 10°C/km
Unstable - ELR greater than DALR
• ELR > 10°C/km
Neutral - no effect on vertical movement
• ELR = 10°C/km

72. Match List-I (Statistical Test) with List-II (Applications).

Choose the correct answer from the options given below:
Codes:

Option(a)(b)(c)(d)
A(i)(ii)(iii)(iv)
B(ii)(iii)(iv)(i)
C(iii)(iv)(i)(ii)
D(iv)(i)(ii)(iii)
Correct Answer: C.

73. Match List-I (Environmentally significant Days) with List-II (Dates).

List-I (Environmentally significant Days)List-II (Dates)
(a) World Ozone Day(i) 16 September
(b) World Habitat Day(ii) 21 March
(c) World Forest Day(iii) 5 October
(d) World Water Day(iv) 22 March

Choose the correct answer from the options given below:
Codes:

Option(a)(b)(c)(d)
A(iv)(iii)(i)(ii)
B(ii)(i)(iv)(iii)
C(i)(iii)(ii)(iv)
D(iii)(i)(iv)(ii)
Correct Answer: C.
Solution:

1. September 16 was designated by the United Nations General Assembly as the International Day for the Preservation of the Ozone Layer. This designation had been made on December 19, 2000, in commemoration of the date, in 1987, on which nations signed the Montreal Protocol on Substances that Deplete the Ozone Layer.

2. In 1985 the United Nations designated the 5th October every year as World Habitat Day. The idea is to reflect on the state of our towns and cities and the basic right of all to adequate shelter. It is also intended to remind the world of its collective responsibility for the future of the human habitat.

3. The International Day of Forests was established on the 21st day of March, by resolution of the United Nations General Assembly on November 28, 2012. Each year, various events celebrate and raise awareness of the importance of all types of forests, and trees outside forests, for the

4. benefit of current and future generations. World Water Day, held on 22 March every year since 1993, focuses on the importance of freshwater.

World Water Day celebrates water and raises awareness of the 2.2 billion people living without access to safe water. It is about taking action to tackle the global water crisis.

A core focus of World Water Day is to support the achievement of Sustainable Development Goal 6: water and sanitation for all by 2030.

74. Match List-I (Processes) with List-II (Energy Transfer).

List-I (Processes)List-II (Energy Transfer)
(a) Conduction(i) Energy is transferred by motion of a fluid
(b) Convection(ii) Energy is transferred in the form of electromagnetic waves through a vacuum
(c) Radiation(iii) Energy is transferred between two points in a material at different temperatures
(d) Evaporation(iv) Energy is lost through a phase change

Choose the correct answer from the options given below:
Codes:

Option(a)(b)(c)(d)
A(ii)(i)(iii)(iv)
B(ii)(iv)(iii)(i)
C(iii)(iv)(ii)(i)
D(iii)(i)(ii)(iv)
Correct Answer: D.
Solution:

75. A strategy favoured by r-selection is:

Correct Answer: D. Higher proportional allocation to reproductive activities.
Solution:

The crucial evidence needed for r- and Kselection is whether an organism is allocating a greater proportion of its resources to reproductive activities (r-strategists) than another related one (K-strategist) under any and all D.D. and D.I. mortality conditions.

76. Traditionally membranes have been classified based on the minimum size of the contaminant that is excluded from passing through the particular membrane. Arrange the following in the correct sequence of decreasing pore size.

(a) Reverse Osmosis
(b) Nanofiltration
(c) Microfiltration
(d) Ultrafiltration
Choose the correct answer from the options given below:

Correct Answer: C. (c), (d), (b), (a)
Solution:

There are four levels of membrane filtration. These levels are (from largest to smallest pore size): microfiltration, ultrafiltration, nanofiltration, and reverse osmosis. Each level has a pore size range associated with it and is used to remove certain sized contaminants.

Filtration LevelMicrofiltrationUltrafiltrationNanofiltrationReverse Osmosis
Pore Size Range0.05-1.0 μm0.005-0.5μm0.0005-0.01μm0.0001-0.001 μm
Target ContaminantsParticulate material like algae, Giardia, Crypto, bacteria, and claysAll substances removed by microfilters plus humic acids and some virusesAll substances removed by microfilters and ultrafilters plus dissolved metals and saltsAll substances removed by microfilters, ultrafilters, nanofilters plus smaller dissolved metals and salts

77. For a given noise signal, what would be the correct order of noise indices in terms of increasing values?

(a) L₁₀
(b) L₅₀
(c) L₁
(d) L₉₀
Choose the correct answer from the options given below:

Correct Answer: D. (d) < (b) < (a) < (c)
Solution:

The commonly used values of n for the n-per cent exceeded level, Ln are 10, 50, and 90. L10 is the level exceeded for 10% of the time. For 10% of the time, the sound or noise has a sound pressure level above L10.

For the rest of the time, the sound or noise has a sound pressure level at or below L10.These higher sound pressure levels are probably due to sporadic or intermittent events. L50 is the level exceeded for 50% of the time.

It is statistically the mid-point of the noise readings. It represents the median of the fluctuating noise levels. L90 is the level exceeded for 90% of the time. For 90% of the time, the noise level is above this level.

It is generally considered to be representing the background or ambient level of a noise environment. L90 is often used to quantify the background noise levels in assessments of noise pollution and nuisance noise from industrial sources.

78. Identify the correct sequence of steps involved in the development of a model.

(a) Validation
(b) Formulation
(c) Identification
(d) Solution
Choose the correct answer from the options given below:

Correct Answer: C. (c), (b), (d), (a)

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

Assertion (A) : Plants generally reflect radiation highly in the nearinfrared region of the electromagnetic spectrum.

Reason (R) : Plant leaves generally contain high chlorophyll content.

In light of the above statements, choose the correct answer from the options given below:

Correct Answer: B. Both (A) and (R) are true, but (R) is NOT the correct explanation of (A)
Solution:

Healthy plants have a high reflectance in the near-infrared between 0.7 and 1.3 µm. This is primarily due to healthy internal structure of plant leaves.

As this internal structure varies amongst different plant species, the near infrared wavelengths can be used to discriminate between different plant species.

The contents of chlorophyll a are usually three times higher than chlorophyll b in the leaf tissue.

The molecular formula for chlorophyll a is C5J H72 N4 O5 Mg and chlorophyll b is C55 H70 N4 O6 Mg.

The chlorophyll molecule contains a porphyrin 'head' and a phytol 'tail'. Hence, Both (A) and (R) are true, but (R) is NOT the correct explanation of (A)

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

Assertion (A) : Tropopause acts as a 'lid' limiting both convection and transport from the troposphere into the higher layers of the atmosphere.

Reason (R) : At tropopause height and at higher levels, the atmosphere is stable.

In light of the above statements, choose the correct answer from the options given below:

Correct Answer: A. Both (A) and (R) are true and (R) is the correct explanation of (A)
Solution:

The tropopause is a temperature inversion level (i.e., where a layer of relatively warm air lies above a colder one); the inversion thus acts as a 'lid' limiting both convection and transport from the troposphere into the higher layers of the Earth's atmosphere.

Industrial pollutants from the Earth's surface  are, therefore, only slowly diffused into the upper atmosphere from the troposphere.

The tropopause is the boundary in the Earth's atmosphere between the troposphere and the stratosphere. At tropopause height and at higher levels, the atmosphere is stable.