UPSC 2008 Prelims Questions with Answers

Explanation

Option (b) is correct: Rubies and sapphires are both varieties of the mineral corundum, which is chemically known as aluminium oxide (Al₂O₃). The difference between rubies and sapphires lies in the trace elements present in them. Rubies get their red color from the presence of trace amounts of chromium. Sapphires can come in various colors, but they are typically blue due to trace amounts of iron and titanium. Options (a), (c) and (d) are incorrect:

Silicon dioxide (SiO₂) is the chemical compound for quartz, Lead tetroxide (Pb₄O₆) is a compound containing lead and oxygen and Boron nitride (BN) is a compound of boron and nitrogen. All three are not related to rubies or sapphires.

Explanation

Option (c) is correct: Xenon: Approximately 0.0000087% of Earth’s atmosphere, known as "stranger gas" due to its unusual behavior among noble gases. Unlike other noble gases, xenon can form compounds with other elements, such as xenon fluorides. It is used in high-intensity discharge lamps and flash lamps for bright illumination, explored as an anesthetic agent and in imaging techniques for the brain, heart, and lungs, and utilized in ion propulsion systems for satellites, contributing to efficient space travel. Options (a), (b) and (d) are incorrect:

Argon (Ar): Approximately 0.934% of Earth’s atmosphere, used in welding to create an inert atmosphere, in incandescent and fluorescent light bulbs to protect filaments from oxidation, and has potential as a neuroprotectant in medical applications. Neon: Neon (Ne) makes up about 0.0018% of Earth’s atmosphere. It is known for its use in neon signs that emit a reddish-orange glow. Neon is also used in lasers with helium to create specific light wavelengths. It helps detect leaks by identifying trace gases and is used as a cryogenic material for preserving biological specimens. Nitrous Oxide: Nitrous Oxide (N₂O), also called laughing gas, is colorless, odorless, and non-flammable. It has anesthetic properties and is used for minor surgeries and dental procedures. In the culinary field, it is used in whipped cream dispensers. In racing, it enhances engine power by allowing more fuel to burn, improving performance.

Explanation

A is matched with 2: Nagender Singh served as the President of the International Court of Justice. B is matched with 3: A. N. Ray held the position of Chief Justice of India. He is well remembered for his controversial elevation as Chief Justice during the tenure of Indira Gandhi’s government, which was perceived as politically motivated. C is matched with 1: R. K. Trivedi was the Chief Election Commissioner of India. D is matched with 4: Ashok Desai served as the Attorney General of India. The Attorney General is the top legal advisor to the government of India and represents the government in the Supreme Court.

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).