Previous Year UPSC Questions

Explanation

A fluorescent lamp or fluorescent tube is a gas discharge lamp that uses electricity to excite mercury vapour. The excited mercury atoms produce shortwave ultraviolet light that then causes a phosphor to fluoresce, producing visible light. The choke coil reduces current in the circuit. A choke coil, also known as an inductor, is used in fluorescent tubes to limit the current flowing through the circuit. It provides impedance to the alternating current (AC) which helps in stabilizing the current and preventing it from reaching excessively high levels. The choke coil does not step up or step down the voltage (these functions are typically performed by a transformer).

Explanation

A is matched with 1: The Chittagong Armoury Raid was led by Surya Sen and Kalpana Dutt, aimed at seizing arms from the British. The raid was conducted in April 1930 and involved 65 activists under the banner of Indian Republican Army--Chittagong Branch. B is matched with 3: Abhinav Bharat was set up by Vinayak Damodar Savarkar and his brother Ganesh Damodar Savarkar in the year 1904, as a secret organization during the Indian War of Independence with the aim of overthrowing British rule. C is matched with 4: Anushilan Samiti traces its history back to 1902 when it was established by Barrister Promotha Mitter and his friends in present-day Kolkata. Aurobindo Ghosh was closely associated with the Samiti. D is matched with 2: Kuka Movement was a socio-religious reform movement led by Guru Ram Singh in Punjab.

Explanation

Statement 1 is correct: The Indian rupee has been fully convertible on the current account since 1994, meaning that individuals and businesses can freely exchange rupees for foreign currency for trade, services, education, travel, and remittances. This was a key reform under the Liberalized Exchange Rate Management System (LERMS) and later formalized under FEMA 1999.

Statement 2 is incorrect: The rupee is not fully convertible on the capital account due to restrictions on capital flows, foreign investments, and external borrowings to prevent excessive volatility and capital flight. India follows a managed convertibility regime under RBI regulations.

Statement 3 is incorrect: The rupee is not convertible into gold, as India does not follow a gold standard. The exchange rate is determined by market forces and central bank interventions, not by a fixed gold reserve system.

Explanation

The growth rate of per capita income at current prices is higher than at constant prices because the latter accounts for inflation. Current price per capita income measures total income without adjusting for inflation, meaning it reflects nominal growth. Constant price per capita income is adjusted for inflation using a base year price index, giving a more accurate picture of real income growth. Since inflation increases the price of goods and services over time, the difference between nominal and real per capita income growth is due to rising price levels. For example, if nominal per capita income grows by 10% and inflation is 5%, the real (constant price) per capita income would only increase by 5% after adjusting for inflation.

Explanation

Assertion (A) is true: After the economic liberalization of 1991, India’s exports rate grew significantly, driven by policy reforms, trade liberalization, and integration with global markets. For instance, India’s merchandise exports rose from around $18 billion in 1991 to over $43 billion by 2000. This period saw increased foreign investments, removal of trade barriers, and diversification of export products, particularly in the IT and services sector. Reason (R) is true: One of the key policy measures undertaken during 1991 was the devaluation of the Indian rupee by nearly 20% in two successive adjustments. This made Indian exports cheaper and more competitive in global markets, boosting export volumes. As per the Economic Survey 1991-92, devaluation was a crucial step in addressing India’s Balance of Payments crisis, enhancing foreign exchange reserves, and accelerating export-driven growth. While devaluation in 1991 contributed to making exports more competitive, the sustained increase in export growth was primarily due to broader economic reforms like trade liberalization, reduction of tariffs, and policies promoting foreign investment, not just devaluation. Hence, R is not the sole or direct reason for the appreciable export growth. Hence, R does not ex-plain A completely.

Explanation

In an open economy, national income (Y) is determined by the sum of domestic consumption (C), investment (I), government spending (G), and net exports (X - M), where exports (X) contribute positively to income, and imports (M) reduce it. The standard macroeconomic equation for national income in an open economy is: Y = C+I+G+(X-M). This formula accounts for domestic economic activity as well as international trade. Net exports (X - M) adjust income by subtracting the value of imports, ensuring only domestically produced goods and services contribute to national income. As per the International Monetary Fund (IMF) Macroeconomic Framework, this equation is widely used in national income accounting for open economies, including India.

Explanation

Option (c) is correct: A CD (Compact Disc) audio player uses a laser beam to read the digital information encoded on the surface of the disc. The laser scans the tiny pits and lands that represent the audio data, and the player converts this data into an audio signal. Options (a), (b) and (d) are incorrect:

Quartz crystal: Used in electronic devices like oscillators and watches, but not for sound reproduction in a CD player. Titanium needle: Historically used in turntables or record players (vinyl), not in CD players. Barium titanate ceramic: Used in piezoelectric devices like speakers, but not in reading CDs.

Explanation

In context of the year in which this question has been asked, The Mumbai Port is India’s largest port in terms of tonnage handled for import cargo. It has historically managed the highest volume of cargo, including crude oil, petroleum products, and containerized imports, making it a crucial gateway for India’s trade.

Explanation

A TV remote control typically uses radio waves to communicate with the TV set. Radio waves are a form of electromagnetic radiation that enables the remote to send signals over short distances to control the television. Radio waves are widely used in radio and television broadcasting, enabling the transmission of audio and video signals over long distances. They are also essential in wireless communication systems, including mobile phones, Wi-Fi, and satellite communication. Note: In many sources, infrared waves are identified as the mechanism behind the functioning of TV remote controls, but this option is not provided in the given choices.

Explanation

A black hole is a region in space where gravity is so intense that not even light or any form of radiation can escape from it. This extreme gravitational pull is a result of its very high density, as the mass of the black hole is compressed into a very small volume, creating a gravitational field strong enough to trap light and radiation. Event Horizon: The boundary around a black hole beyond which nothing, not even light, can escape due to the extreme gravitational pull. Singularity: The point at the center of a black hole where gravity is infinitely strong, and matter is thought to be crushed to an infinitely small point with infinite density. Schwarzschild Radius: The radius of the event horizon, which depends on the mass of the black hole. It defines the size of the black hole’s event horizon. Accretion Disk: A rotating disk of matter, such as gas and dust, that orbits a black hole. The matter in the disk heats up as it spirals toward the event horizon. Hawking Radiation: A theoretical prediction by physicist Stephen Hawking that black holes can emit radiation due to quantum effects near the event horizon, eventually leading to their slow evaporation.