Fundamentals of Environmental Sciences MCQ Quiz in தமிழ் - Objective Question with Answer for Fundamentals of Environmental Sciences - இலவச PDF ஐப் பதிவிறக்கவும்

The correct answer is 1) Only 2.

Key PointsUnderstanding the statements in relation to Sustainable Development

• Levels of Consumption
  • Sustainable development aims to balance consumption with the earth's ability to regenerate resources.
  • While it emphasizes efficiency and reducing waste, it does not strictly limit consumption but rather promotes sustainable practices that can support different levels of consumption responsibly.
  • Therefore, sustainable development does not strictly mean supporting limited levels of consumption. Hence statement 1 is incorrect.
• Quality of Life and Population Growth
  • Sustainable development is designed to support a high quality of life through the efficient use of resources, renewable energy, and sustainable practices.
  • It aims to meet the needs of the present without compromising the ability of future generations to meet their own needs.
  • This can be achieved even with continued population growth, provided that growth is managed sustainably. Hence statement 2 is correct.
• Sustainable Development for All Countries
  • Sustainable development is a global goal and is not limited to wealthy countries.
  • It involves equitable resource distribution, technological advancements, and environmental conservation that can be implemented in both developed and developing countries.
  • Therefore, sustainable development is achievable for all nations, not just wealthy ones. Hence statement 3 is incorrect.

Additional Information

• Principles of Sustainable Development
  • Sustainable development involves three core components: economic development, social development, and environmental protection.
  • It promotes responsible consumption, renewable energy use, and policies that support long-term environmental health and social equity.
• Sustainable Practices
  • Examples include using renewable energy sources, sustainable agriculture, water conservation, and reducing carbon footprints.
  • Such practices help in achieving a balance between growth, resource availability, and environmental conservation.

The correct answer is Our success depends on learning how nature sustains itself and integrating such lessons from nature into the ways we think.

 Key Points

• Major environmental worldviews differ on which is more important—human needs and wants, or the overall health of ecosystems and the biosphere.
• There are a variety of environmental worldviews that represent that environmental wisdom, such as:
  • ​We are a part of and dependent on nature, and nature exists for all species.
  • Resources are limited and should not be wasted.
  • We should encourage earth-sustaining forms of economic growth and discourage earth-degrading forms.
  • Our success depends on learning how nature sustains itself and integrating such lessons from nature into the ways we think and act.

Therefore, the correct answer is our success depends on learning how nature sustains itself and integrating such lessons from nature into the ways we think.

The correct answer is (b) and (c) only.

Key Points

• The world’s forests cover 30% of the earth’s surface and serve as a source of diverse values to human society.
• Healthy forest ecosystems provide a wide range of services – including:
  1. Reliable clean water 
  2. Climate regulation
  3. Productive soils
  4. Pollination by insects and birds
  5. Biodiversity
  6. Carbon
  7. Watershed services
  8. Soil conservation
  9. Recreational and cultural values
  10. Social and economic benefits for communities
  11. High Conservation Values

Not only are forests home to more than 80% of all species living on land, but they are also crucial sources of food, medicine, drinking water, and immense recreational, aesthetic, and spiritual benefits for millions of people.

Therefore, the correct answer is (b) and (c) only.

Additional Information

Experts have identified four different kinds of services, all vital to human health and well-being:

• Provisioning services supply the goods themselves, such as food, water, timber and fibre.
• Regulating services govern climate and rainfall, water (e.g. flooding), waste, and the spread of disease.
• Cultural services cover the beauty, inspiration and recreation that contribute to our spiritual welfare.
• Supporting services include soil formation, photosynthesis and nutrient cycling, which underpin growth and production.

The correct answer is (a), (b), (c) and (d).

 Key Points

• Water vapour is the most abundant greenhouse gas in the atmosphere, both by weight and volume. 
• It is also an effective greenhouse gas, as it does absorb longwave radiation and radiates it back to the surface, thus contributing to warming. 
• When compared to other greenhouse gases, water vapour stays in the atmosphere for a much shorter time.
• The increase in water vapour in the atmosphere thus contributes to even more warming i.e., it enhances the greenhouse effect.
• It plays a key role in climate feedback because of its heat-trapping ability.
• Warmer air holds more moisture than cooler air.
• Therefore, as greenhouse gas concentrations increase and global temperatures rise, the total amount of water vapour in the atmosphere also increases, further amplifying the warming effect.
• It is a radiatively active gas with absorption wavelengths of less than 8 μm and greater than 18 μm. 
• 0.94 µm, 1.14 µm, 1.40 µm and 1.88 µm all fall under less than 8 μm wavelength.

Therefore, the correct answer is (a), (b), (c) and (d).

The correct answer is Polycyclic Aromatic Hydrocarbons.

Key Points

Photochemical smog:

• Photochemical smog is a mixture of pollutants that are formed when nitrogen oxides and volatile organic compounds (VOCs) react to sunlight, creating a brown haze above cities.
• It tends to occur more often in summer because that is when we have the most sunlight. 

Primary pollutants:

• The two major primary pollutants, nitrogen oxides and VOCs combine to change in sunlight in a series of chemical reactions, to create what is known as secondary pollutants.

Secondary pollutants:

• The secondary pollutant that causes the most concern is the ozone that forms at ground level.
• While ozone is produced naturally in the upper atmosphere, it is a dangerous substance when found at ground level.
• Many other hazardous substances are also formed, such as peroxyacetyl nitrate (PAN).  

Pollutants involved in photochemical smog:

• Nitrogen oxides
• Volatile organic compounds (VOCs)
• Ozone
• Peroxyacetyl nitrate (PAN)
• Peroxy Benzoyl Nitrate (PBN)

Therefore, the correct answer is Polycyclic Aromatic Hydrocarbons.

The correct answer is Nitrate radicals.

Key Points

• The chemistry of the night-time atmosphere is dominated by the nitrate radical (NO₃).
• These nitrate radicals are formed from the reaction of ozone (O₃) with nitrogen dioxide (NO₂). 
• The reaction of NO₃ with NO₂ is the only way to form dinitrogen pentoxide (N₂O₅) in the atmosphere. 
• This N₂O₅ acts as a store of NO₃.
• It can either decompose back to NO₃ and NO₂ or react with water to form nitric acid (HNO₃). 
• NO₃ reacts with organic molecules in the same way as OH does. 
• It removes a hydrogen atom from alkanes to form an organic alkyl radical (R) which then reacts with O₂ in the air to form peroxy radicals (RO₂). 
• The radical is broken down by sunlight when the sun rises. 
• NO₃ adds also to the double bonds of unsaturated organic compounds and forms peroxy nitrates after the addition of O₂. 
• The lifetime of NO₃ / N₂O₅ decreases drastically as concentrations of water vapour increase. 
• As water vapour levels increase, more of the NO₃ is converted to nitric acid (HNO₃), in particular on liquid films on surfaces. 

Therefore, the correct answer is Nitrate radicals.

The correct answer is Lowest temperature is found at the tropopause.

Key PointsLet us analyze the graphical representation of temperature variation with altitude.

• As we can see, the temperature in the thermosphere and stratosphere increases with an increase in altitude. Therefore, statement 1 is correct.
• There is a decrease in temperature with an increase in altitude in the troposphere and mesosphere. Therefore, statement 2 is correct.
• The lowest temperature is found at the mesopause. Therefore, statement 3 is incorrect.
• The lapse rates determine the vertical stability of the atmosphere because if the lapse rate is greater than the dry-adiabatic lapse rate favours vertical motion and is unstable. The atmosphere is stable if it is less than the dry-adiabatic lapse rate. Hence statement 4 is correct.

Therefore, the correct answer is lowest temperature is found at the tropopause.

The correct answer is (i), (ii), and (iii).

Key Points

• Range resolution is the ability of a radar to distinguish between two or more targets that are very close to each other.
• The degree of range resolution depends on the width of the transmitted pulse. the type and size of the target. 
• Radar resolution is defined as the minimum separation between two objects of equal reflectivity that will enable them to appear individually in a processed radar image. 
• Radar systems are generally used to distinguish point targets; the impulse response defines their ability to do so.

The formula for determining the ground-range resolution is:

\(R_{gr} = {cτ\over 2\cos\ β}\)

Where τ is the pulse compression, c is the speed of light, and β angle of depression which is also denoted by θ_d.

Thus range resolution in radar is a function of pulse compression, speed of light, and angle of depression.

Therefore, the correct answer is (i), (ii), and (iii).

The correct answer is: '(2) 1, 3, and 4'.

Key Points

• Remote sensing data can be used to monitor urban expansion and the rate of land conversion from agricultural to urban areas.
  • This statement is correct.
  • Remote sensing enables authorities to observe and quantify changes in land cover over time, including urban expansion and the conversion of land from agricultural use to urban use.
  • High-resolution satellite images and aerial photography can provide detailed insights into how land is being utilized and how it is changing.
• Remote sensing is ineffective in detecting vegetation cover changes in large areas over time.
  • This statement is incorrect.
  • Remote sensing is highly effective in monitoring vegetation cover over large areas, especially with the use of vegetation indices like NDVI. It provides valuable information on land use and environmental health.
• GIS helps authorities manage and plan for urban growth by providing spatial and temporal data on land use changes.
  • This statement is correct.
  • Geographic Information Systems (GIS) integrate spatial and temporal data, allowing planners to make informed decisions regarding land use and urban development based on historical and predictive data.
• Vegetation indices, such as the Normalized Difference Vegetation Index (NDVI), are commonly derived from remote sensing data for monitoring vegetation health.
  • This statement is correct.
  • NDVI is one of the most widely used indices derived from remote sensing data, as it helps in assessing vegetation health and cover by comparing the visible and near-infrared light reflected by vegetation.

Additional Information

• Remote Sensing and Land Use Planning:
  • Remote Sensing: It refers to the acquisition of information about an object or phenomenon without making physical contact. This is often used to monitor land cover and land use through satellites or aerial imagery.
  • GIS: GIS is used in land use planning to manage and analyze spatial data, helping in decision-making processes related to urban growth, deforestation, and conservation efforts.
  • NDVI: NDVI is an important vegetation index that is widely applied in agriculture and forestry for assessing vegetation health and changes over time.

The correct answer is: '(4) 1, 2, and 3'.

Key Points

• Polar orbits enable satellites to scan almost every part of the Earth due to Earth's rotation underneath.
  • This statement is correct.
  • Satellites in polar orbits travel around the Earth from pole to pole, and as the Earth rotates beneath them, they can scan almost every region of the planet.
  • This orbit is ideal for Earth observation and environmental monitoring, allowing frequent coverage of all areas.
• Sun-synchronous orbits allow satellites to pass over the same location at the same solar time each day.
  • This statement is correct.
  • In a sun-synchronous orbit, a satellite passes over any given point on Earth's surface at the same local solar time, providing consistent lighting conditions for imaging.
  • This is particularly useful for scientific observation and environmental monitoring, as it ensures comparability of images over time.
• Geostationary satellites appear stationary to an observer on the Earth’s surface and are ideal for weather monitoring.
  • This statement is correct.
  • Geostationary satellites orbit at the same speed as the Earth's rotation, staying fixed over one spot. This makes them useful for continuous monitoring of specific regions, such as for weather forecasting and communication.
  • These satellites orbit at a high altitude, approximately 35,786 km above the equator.
• Polar orbits are generally used for communication satellites due to their high altitude and stationary nature.
  • This statement is incorrect.
  • Polar orbits are typically used for Earth observation, not for communication. Communication satellites are more often placed in geostationary orbits, which allow them to maintain a fixed position relative to the Earth's surface.

Additional Information

• Satellite Orbits and Their Uses:
  • Polar Orbit: Polar orbits are low Earth orbits that pass over the Earth’s poles. They are ideal for global data collection and Earth observation.
  • Sun-Synchronous Orbit: These orbits are designed to ensure that the satellite crosses the same point at the same local solar time, making them optimal for scientific studies and consistent imagery.
  • Geostationary Orbit: A geostationary orbit is ideal for communication, weather monitoring, and broadcasting because the satellite remains fixed relative to a point on the Earth's surface.
  • Communication Satellites: These are generally placed in geostationary orbits for uninterrupted, real-time data transmission over large areas.