Previous Year UPSC Questions

Explanation

Bisphenol A (BPA) is an industrial chemical extensively used in the production of polycarbonate plastics and epoxy resins. Polycarbonate plastics made using BPA are commonly employed in the manufacture of reusable water bottles, food containers, and baby bottles due to their durability and lightweight properties. Epoxy resins containing BPA are used as coatings for the inside of food and beverage cans to prevent corrosion and contamination. However, BPA is a controversial substance because it can leach into food and beverages under high temperatures or prolonged storage. It is considered a potential endocrine disruptor that may interfere with hormonal activity, prompting regulatory bodies worldwide to evaluate its safety in food-related applications.

Explanation

Methane and air are responsible for mine explosions, often referred to as fire damp explosions. Methane (CH₄) is a flammable gas that accumulates in coal mines. When mixed with air in the presence of a spark, it can cause deadly explosions. Options (a), (b) and (d) are incorrect:

While Hydrogen and Oxygen are explosive, these gases are not significantly common in mining environments. Oxygen and Acetylene are used in welding, not relevant to mine explosions. Carbon Dioxide and Methane: Carbon dioxide is inert and cannot contribute to mine explosions.

Explanation

The Omkareshwar Project, a multi-purpose dam project, is located in the Khandwa district of Madhya Pradesh, India. This project utilizes the Narmada River, a major river system in central India, to achieve several key objectives such as:

A primary function is the generation of hydroelectric power, with a station capacity of 520 MW, contributing substantially to the regional energy supply. The project is intended to provide irrigation to extensive agricultural lands, thereby increasing agricultural productivity and supporting local economies. The Omkareshwar Project also plays a role in supplying water for domestic and industrial use, ensuring access to this vital resource. The dam itself is situated on the Narmada River, proximate to the town of Omkareshwar, a significant Hindu pilgrimage site. The town’s religious importance derives from the presence of the Omkareshwar Temple, dedicated to Lord Shiva.

Explanation

India’s extensive coastline, stretching approximately 7,516 kilometers, is shared by nine diverse states, each contributing unique characteristics to the nation’s maritime heritage. Starting from the west: Gujarat boasts the longest coastline in India which dotted with numerous ports and playing a crucial role in maritime trade. Maharashtra’s coastline is home to the bustling metropolis of Mumbai, a major commercial and entertainment hub. Goa is renowned for its beautiful beaches and vibrant tourism industry. Karnataka’s coastline is significant for its port cities and coastal cuisine. Kerala is famed for its backwaters, lush greenery, and historical spice trade connections. On the eastern coast: Tamil Nadu possesses a long coastline with important ports and cultural significance, including the historic city of Chennai. Andhra Pradesh which is located north of Tamil Nadu has a substantial coastline crucial for fishing and maritime activities. Odisha, known for its rich cultural heritage, also has a significant coastline vulnerable to cyclones. West Bengal features a coastline that includes the Sundarbans, a unique mangrove ecosystem and a UNESCO World Heritage Site. In addition to the nine states, India’s coastline is also shared by four Union Territories:

Andaman and Nicobar Islands archipelago in the Bay of Bengal boasts the longest coastline among all the Union Territories. These islands are known for their pristine beaches, diverse marine life, and lush tropical forests. They hold strategic importance for India and are a hub for tourism and biodiversity. Lakshadweep located in the Arabian Sea is a group of coral islands. These islands are known for their beautiful lagoons, coral reefs, and white sandy beaches. They are a popular destination for those seeking tranquility and water sports activities. Puducherry on the southeastern coast of India has a relatively short coastline. Puducherry is known for its French colonial heritage, serene atmosphere, and the Sri Aurobindo Ash-ram. Its coastline features beaches and promenades. Daman and Diu is situated on the western coast, Daman and Diu is a Union Territory with a coastline along the Arabian Sea. Daman is on the mainland, while Diu is a small island. They are known for their beaches, historical sites, and relaxed atmosphere.

Explanation

Option (a) is incorrect: Anamalai Hills, also known as the Elephant Hills, are a mountain range located in the Western Ghats, primarily within the states of Kerala and Tamil Nadu. They are renowned for their high peaks, including Anamudi, the highest peak in Southern India. While significant within the Western Ghats, the Anamalai Hills are not situated at the confluence of the Eastern and Western Ghats.

Option (b) is incorrect: The Cardamom Hills, part of the Western Ghats, are situated in Kerala and Tamil Nadu. They are named for the cardamom spice that is cultivated extensively in this region. These hills are known for their biodiversity and dense forests.

Option (c) is correct: The Nilgiri Hills are a mountain range located in the Western Ghats of Tamil Nadu. They are recognized as the junction point of the Eastern and Western Ghats mountain ranges. The region is characterized by its rolling hills, tea plantations, and diverse flora and fauna. The Nilgiris’ significance lies in their unique geographical position which provides bridge between the two distinct mountain systems. Ooty (Udhagamandalam), the famous hill station is located in the Nilgiris.

Option (d) is incorrect: The Shevaroy Hills are a smaller mountain range located in the Eastern Ghats of Tamil Nadu. They are known for their coffee plantations and the hill station of Yercaud. As part of the Eastern Ghats, the Shevaroy Hills are geographically separate from the meeting point of the Eastern and Western Ghats, which is defined by the Nilgiri Hills.

Explanation

Pair (1) is incorrectly matched: The Chambal River is a major tributary of the Yamuna River, a significant river in North India. The Narmada River, on the other hand, flows westward and is independent of the Yamuna and Chambal river systems. These two rivers are geographically separated and do not share a tributary-main river relationship.

Pair (2) is incorrectly matched: The Sone River is a tributary of the Ganga River, not the Yamuna. It originates in the Amarkantak Plateau (Madhya Pradesh) and joins the Ganga near Patna.

Pair (3) is correctly matched: Manas originates in the Himalayas in Bhutan and flows through Assam. It joins the Brahmaputra near Jogighopa. It is known for its rich biodiversity and is part of the Manas National Park, a UNESCO World Heritage Site.

Explanation

Statement 1 is correct: The saltwater crocodile (Crocodylus porosus) is India’s largest reptile and is found in the mangroves and coastal waters of:

Andaman & Nicobar Islands (notably in North & Middle Andaman) Bhitarkanika National Park, Odisha Sundarbans, West Bengal Mahanadi & Godavari estuaries They are apex predators inhabiting coastal areas, estuaries, rivers, and mangrove swamps. The Andaman and Nicobar Islands provide suitable habitats for these crocodiles. Bhitarkanika holds the record for the world’s largest saltwater crocodile, measuring 7.1 meters (23 feet)

Statement 2 is incorrect: Shrews are small mammals found in various parts of India, including the Western Ghats but they are not exclusive to the Malabar region. Tapirs are not found in India. They are native to Central and South America, as well as Southeast Asia (Malayan tapir).

Explanation

Coal mining plays a crucial role in India’s energy sector, and the Namchik-Namphuk coalfields are an important part of India’s northeastern coal reserves.

Option (a) is correct: Arunachal Pradesh: Arunachal Pradesh’s primary coal resource is concentrated in the Namchik-Namphuk coalfields located in the Changlang district. These are the most significant coal-bearing areas in the state, though they are relatively small compared to major coalfields elsewhere in India. The coal found here is generally of tertiary age.

Option (b), (c) and (d) are incorrect:

Meghalaya possesses coal deposits, primarily in the Garo Hills region, which includes areas like Nangalbibra, Siju, and others. The coal here is typically sub-bituminous. It’s important to note that much of the coal mining in Meghalaya is done through small-scale, often unregulated operations (rat-hole mining) which has raised environmental concerns. Manipur has limited coal resources, and no significant, named coalfields are widely recognized. Coal occurrences are scattered and generally not considered commercially viable. Exploration has been carried out in areas like the Ukhrul district, but large-scale mining operations are not a feature of the state. Mizoram has no significant coalfields within the state. Coal occurrences are scattered and not considered economically significant. The geological formations in Mizoram are not conducive to the formation of large, commercially viable coal deposits.

Explanation

Chhattisgarh has significant deposits of bauxite, particularly in the Maikal Hills and the Surguja district. The mineral is found in is associated with lateritic formations. These bauxite deposits contribute to India’s aluminum industry. Dolomite is a sedimentary rock composed primarily of calcium magnesium carbonate, is another mineral resource found in Chhattisgarh. It is found in the Bastar and Durg districts of Chhattisgarh. Dolomite is used in the steel industry, cement manufacturing, and as a source of magnesium. Dolomite is used in a range of industrial applications, including cement manufacturing, steelmaking, and as a fluxing agent. Chhattisgarh is endowed with substantial deposits of iron ore, a crucial raw material for the steel industry. The state’s iron ore reserves are known for their quality and contribute significantly to India’s steel production capacity. Major deposits are found in the Bailadila range in the Dantewada district which is known for its high-grade hematite iron ore.. Chhattisgarh is one of the few states in India where tin ore is found in commercially viable quantities. The state has tin deposits, particularly in the Bastar region. Tin is a relatively rare metal and is used in various applications, including alloys, solder, and plating.

Explanation

The Tehri Hydropower Complex is located on the Bhagirathi river. This complex features a towering earth and rock-fill dam, one of the world’s tallest. The project has also spurred regional development in Garhwal including a new town and improved infrastructure. Bhagirathi River is considered the primary source stream of the Ganges. It emerges from the Gangotri Glacier in Uttarakhand