Paper-1 | People & Environment

Nuclear accidents are not considered natural hazards because they are caused by human error or technological failures rather than natural phenomena. Natural hazards, such as earthquakes, tsunamis, and flash floods, are events that occur due to natural processes and are beyond human control. On the other hand, nuclear accidents, like the Chernobyl disaster, are the result of human activities and the failure of nuclear power plants or facilities. These accidents can have severe environmental and health consequences, but they are not classified as natural hazards.

Smog is produced due to the combination of smoke and fog. Smoke refers to the particles and pollutants released from burning fuels, industrial processes, and other sources. Fog, on the other hand, is a weather condition characterized by a dense cloud of tiny water droplets suspended in the air. When smoke particles mix with fog, they create a thick and hazardous mixture known as smog. This combination of pollutants can have detrimental effects on air quality and human health.

Ultraviolet radiation is harmful radiation emitted by the sun. It has shorter wavelengths and higher energy than visible light. Prolonged exposure to ultraviolet radiation can cause damage to the skin, such as sunburns, premature aging, and an increased risk of skin cancer. It is important to protect oneself from the harmful effects of ultraviolet radiation by wearing sunscreen, protective clothing, and sunglasses, and by seeking shade during peak sun hours.

Chlorofluorocarbons (CFCs) are commonly used as refrigerants in refrigeration and air conditioning systems. They are also used as propellants in aerosol cans. CFCs have been found to be harmful to the ozone layer in the Earth's atmosphere. When released into the atmosphere, CFCs can rise to the stratosphere where they are broken down by ultraviolet radiation, releasing chlorine atoms that can destroy ozone molecules. Therefore, the correct answer is refrigeration and air conditioning.

The sun is the correct answer because it is not affected by pollution. Pollution primarily affects the air, water, and land, but it does not directly impact the sun. The sun's quality as a resource remains constant regardless of pollution levels.

The correct answer is the transport sector. In mega cities of India, the transport sector is the dominant source of air pollution. This is due to the large number of vehicles on the roads, including cars, buses, and motorcycles, which emit pollutants such as carbon monoxide, nitrogen oxides, and particulate matter. The high congestion and traffic in these cities exacerbate the problem, leading to poor air quality and negative health effects for the residents.

Acid rain is caused by the presence of sulphur and nitrogen oxides in the atmosphere. When these oxides combine with water vapor, they form sulphuric and nitric acids, which then fall to the ground as acid rain. This phenomenon is primarily a result of human activities such as burning fossil fuels and industrial emissions, which release large amounts of sulphur and nitrogen compounds into the air. These pollutants can travel long distances before being deposited as acid rain, causing harm to ecosystems, damaging buildings and infrastructure, and affecting human health.

Biomass is a renewable source of energy because it is derived from organic materials such as plants, agricultural waste, and wood. These materials can be replenished through natural processes, making biomass a sustainable source of energy. In contrast, uranium, petroleum, and coal are all non-renewable sources of energy because they are finite resources that cannot be replenished within a human lifetime.

A keystone species is characterized by its disproportionate large impact on the ecosystem. This means that even though the keystone species may not be the most abundant or dominant species in the ecosystem, its presence and activities have a significant influence on the structure and function of the entire ecosystem. The removal of a keystone species can cause a cascade of negative effects, leading to the collapse of the ecosystem.

Floods are the most recurring natural hazard in India due to the country's geographical location and climate. India experiences heavy monsoon rains, which often result in overflowing rivers and excessive water accumulation. This leads to widespread flooding in various parts of the country, causing significant damage to infrastructure, crops, and human lives. Additionally, India's vast coastline is prone to cyclones and storm surges, further contributing to the occurrence of floods. The frequency and intensity of floods in India highlight their significance as the most recurring natural hazard in the country.

Solar energy has the maximum potential in India because of its geographical location and abundant sunlight. India is located in the tropical region, which receives high levels of solar radiation throughout the year. This makes solar energy a viable and sustainable source of power generation. Additionally, India has a large landmass and vast rooftops that can be utilized for solar panel installations. The government has also implemented various policies and incentives to promote solar energy adoption, further enhancing its potential in the country.

The correct answer is "The visible surface of the sun from where the radiation emanates." The photosphere is the outermost layer of the sun that emits visible light. It is the layer from which most of the sun's energy and radiation, including sunlight, originates.

Biomagnification refers to the process in which the concentration of pollutants increases as they move up the food chain. As organisms consume other organisms, the pollutants present in the prey accumulate in the predator's body. This is because the predator consumes a larger number of prey organisms, resulting in a higher concentration of pollutants. Over time, this can lead to high levels of pollutants in the top predators of an ecosystem, posing a threat to their health and potentially causing adverse effects on the entire food chain.

Flash floods are caused when the atmosphere is convectively unstable, meaning that there are rapid upward and downward motions of air. This instability, combined with considerable vertical wind shear, which is a change in wind speed or direction with height, creates an environment where thunderstorms can develop and produce heavy rainfall. The convective instability allows for the rapid uplift of warm, moist air, while the vertical wind shear helps to organize and sustain the storm system, leading to intense rainfall and potential flash flooding.

Minamata disease in Japan was caused by pollution due to mercury. Mercury is a highly toxic heavy metal that can accumulate in the environment and contaminate water sources. In the case of Minamata disease, industrial wastewater containing mercury was discharged into Minamata Bay, resulting in the contamination of fish and shellfish. When consumed by the local population, the contaminated seafood led to severe neurological symptoms and disabilities, collectively known as Minamata disease. The mercury poisoning caused by the industrial pollution serves as a tragic example of the devastating effects of environmental contamination on human health.

Madhya Pradesh is termed as the Tiger State because it has the highest number of tigers in India. It is home to several national parks and wildlife sanctuaries, including the famous Bandhavgarh National Park and Kanha Tiger Reserve, which are known for their thriving tiger populations. Madhya Pradesh has made significant efforts in tiger conservation and has implemented various initiatives to protect and preserve these majestic creatures.

Pyrolysis is the correct answer because it refers to the process of converting waste materials, such as biomass or organic matter, into energy or useful products through high temperatures and the absence of oxygen. This method is commonly used to produce electricity from waste materials, making it the most appropriate option among the given choices. Landfill and dumping are not specific to the production of electricity, and "None of these" is not accurate as pyrolysis is a recognized method for this purpose.

The troposphere is the layer of the atmosphere closest to the Earth's surface and is where all weather phenomena occur. It is dynamic because it is constantly in motion, with warm air rising and cool air sinking, creating vertical air currents. This layer is also responsible for the majority of the Earth's climate, as it contains the greenhouse gases that trap heat and regulate temperatures. The other layers of the atmosphere, such as the ionosphere, stratosphere, and mesosphere, are less influenced by weather and have different characteristics and functions.

The Bhopal gas tragedy refers to the catastrophic gas leak that occurred in Bhopal, India in 1984. The incident was caused by the release of a toxic gas called methyl isocyanate (MIC) from a pesticide plant. The gas leak resulted in the immediate death of thousands of people and caused long-term health issues for many more. The gas release into the air led to severe air pollution in the surrounding areas, making air pollution the correct answer.

The correct answer is Oceans. Oceans cover about 71% of the Earth's surface and contain the majority of the planet's water. They hold approximately 97% of the Earth's water, making them the largest reservoir of water on Earth. Oceans play a crucial role in regulating the planet's climate, supporting diverse marine ecosystems, and providing a source of food and resources for human populations.

Solar cells are devices that convert sunlight, which is a form of solar energy, into electrical energy. This is achieved through the photovoltaic effect, where the solar cells absorb photons from the sunlight and generate an electric current. Therefore, the correct answer is "Solar energy into electrical energy."

The correct answer is UNESCO because UNESCO (United Nations Educational, Scientific and Cultural Organization) is responsible for designating and managing World Heritage Sites. These sites are recognized for their outstanding universal value and are considered to be of immense cultural or natural importance to humanity. The World Heritage Committee, which is a part of UNESCO, evaluates and selects these sites based on strict criteria to ensure their preservation and promotion for future generations.

Composting is the most efficient method of biodegradable urban solid waste management. It involves the decomposition of organic waste materials, such as food scraps and yard waste, into nutrient-rich compost. This process not only reduces the volume of waste going to landfills but also produces a valuable product that can be used as a natural fertilizer for plants. Composting is a sustainable and environmentally friendly solution that helps to minimize pollution and greenhouse gas emissions associated with waste disposal.

The Nagoya Protocol is an international agreement that aims to promote the fair and equitable sharing of benefits arising from the utilization of genetic resources. It specifically focuses on the conservation and sustainable use of biological diversity, which includes all living organisms, their genetic material, and the ecosystems they are part of. Therefore, the correct answer is Biological Diversity.

Biomass refers to the total amount of organic matter present in an ecosystem. This includes all living organisms such as plants, animals, and microorganisms, as well as dead organic matter like fallen leaves and decaying wood. It is an important measure of the productivity and health of an ecosystem, as it represents the energy stored within the system. Biomass can be quantified by measuring the weight or volume of the organic matter, and it is often used to estimate the availability of resources and the potential for supporting various trophic levels within the ecosystem.

Lead is used as an anti-knocking agent in fuels, specifically tetraethyl lead. When lead enters the body, it can have toxic effects on various systems. In this case, it affects the central nervous system. Lead exposure can lead to neurotoxicity, causing cognitive and behavioral problems, especially in children. It can impair learning and memory, and even at low levels, it can have long-term effects on the nervous system. Therefore, lead's impact on the central nervous system makes it a significant concern for human health.

PAN (peroxyacetyl nitrate) is a highly reactive pollutant that can cause irritation in the eyes. It is formed when volatile organic compounds (VOCs) and nitrogen oxides (NOx) react in the presence of sunlight. PAN can irritate the eyes, causing redness, itching, and tearing. Exposure to high levels of PAN can also lead to respiratory problems and damage to the respiratory system. Therefore, PAN is the correct answer as it is known to cause eye irritation.

Calcium Carbonate is not a major greenhouse gas. The major greenhouse gases are carbon dioxide, water vapor, and methane. While calcium carbonate does play a role in the carbon cycle and can indirectly affect climate change, it is not considered a major contributor to the greenhouse effect.

Nuclear energy is the correct answer because it is not derived from the sun. Biomass, fossil fuels, and geothermal energy are all forms of energy that ultimately originate from the sun. Biomass is derived from organic matter, which is produced by plants through photosynthesis. Fossil fuels are formed from the remains of plants and animals that lived millions of years ago, also ultimately deriving their energy from the sun. Geothermal energy is heat from within the Earth, which is generated by the radioactive decay of elements, including uranium and thorium, which were formed during the creation of the solar system.

Silver is the metal used in a solar panel because it is an excellent conductor of electricity and has a high reflectivity. These properties make it ideal for capturing and conducting the sun's energy in a solar panel. Additionally, silver is highly resistant to corrosion, which ensures the longevity and durability of the solar panel.

Carbon dioxide is mainly responsible for global warming because of its large quantity in the atmosphere. Carbon dioxide is a greenhouse gas that traps heat from the sun and prevents it from escaping back into space, leading to a rise in global temperatures. Human activities, such as burning fossil fuels and deforestation, have significantly increased the levels of carbon dioxide in the atmosphere, contributing to the greenhouse effect and global warming.

The presence of high algal content in water indicates that the water is acidic. Algae thrive in environments with lower pH levels, which are characteristic of acidic conditions. The high algal content suggests that the water has a higher concentration of dissolved carbon dioxide and other acidic compounds, making it unsuitable for certain aquatic organisms and potentially harmful to human health.

In 2008, India announced a National Action Plan on Climate Change (NAPCC). This plan was developed to address the challenges of climate change and to enhance the country's sustainability and resilience. It aimed to promote the development and deployment of clean and renewable energy sources, improve energy efficiency, and conserve natural resources. The NAPCC also emphasized the need for adaptation measures to protect vulnerable communities and ecosystems from the impacts of climate change.

Red soil is very hard to cultivate because it is highly weathered and lacks essential nutrients for plant growth. It is characterized by its clayey texture and high iron content, which makes it difficult to till and work with. Additionally, red soil tends to have poor water-holding capacity and drainage, leading to waterlogging or drought conditions. These factors make it challenging for plants to establish roots and access the necessary nutrients and moisture for growth, making red soil unsuitable for cultivation without proper soil management techniques.

The correct answer is Elastic rebound theory. This theory explains the build-up and release of stress during an earthquake. According to this theory, the Earth's crust is constantly under stress and when the stress exceeds the strength of the rocks, it causes them to break and slip along a fault line, resulting in an earthquake. The release of stress is accompanied by the sudden movement of the rocks, which causes vibrations and seismic waves. This theory helps in understanding the mechanics of earthquakes and how they occur.

The focus of an earthquake is the point underground where the movement that triggers the earthquake originates. It is the exact location where the rocks break and release energy, causing the ground to shake. The focus can be at varying depths, ranging from shallow to deep within the Earth's crust. The epicenter, on the other hand, is the point on the Earth's surface directly above the focus.

Volcanic eruptions result in the release of ash particles into the atmosphere, which can be carried by wind for long distances. These ash contents can pose a threat to aviation as they can damage aircraft engines, disrupt air traffic, and affect visibility. Additionally, volcanic ash can have detrimental effects on human health, agriculture, and infrastructure. Therefore, the main effect of volcanic eruptions is the flying of ash contents.

Hydrogen has the highest calorific value among the given options. Calorific value refers to the amount of heat energy produced when a fuel is completely burned. Hydrogen has a high calorific value because it has a high energy content per unit mass. When hydrogen is burned, it releases a large amount of heat energy, making it an efficient fuel. This is why hydrogen is often considered as a clean and sustainable energy source for various applications.