UPSC 2001 Prelims Questions with Answers

Explanation

Nuclear fission is the process in which a heavy atomic nucleus, such as uranium-235 or plutonium-239, splits into two smaller nuclei, releasing a large amount of energy.

Statement 1 is correct: Each fission reaction releases multiple neutrons, which are crucial for sustaining the chain reaction.

Statement 2 is correct: The neutrons produced in fission reactions are used to initiate further fission events.

Statement 3 is correct: Graphite (a moderator) slows down fast neutrons, increasing the likelihood that they will cause further fission reactions, thus making reaction sustainable over longer periods.

Statement 4 is incorrect: Not every neutron released will necessarily cause further fission, as some neutrons may escape the reactor or fail to cause fission if not properly moderated.

Explanation

The Comptroller and Auditor General (CAG) of India plays a crucial role in auditing and reporting on the financial transactions of the Indian government. However, some functions fall outside the purview of the CAG’s responsibilities. Statement (a) is correct: The CAG audits and reports on all expenditure from the Consolidated Fund of India, which includes government expenses related to various ministries and departments. Statement (b) is correct: The CAG is responsible for auditing and reporting on all expenditures from the Contingency Funds and Public Accounts. These funds are used for emergency and specific purposes, respectively. Statement (c) is correct: The CAG also audits and reports on trading, manufacturing, and profit and loss accounts of government-owned enterprises and other related entities. Statement (d) is incorrect: The duty of controlling the receipt and disbursement of public money and ensuring public revenue is deposited into the exchequer is managed by other government entities, such as the Ministry of Finance and the Reserve Bank of India.

Explanation

The order of filling up orbitals in an atom is governed by Aufbau’s principle, which states that electrons occupy orbitals in order of increasing energy levels, starting from the lowest energy orbital first. The sequence is determined by the (n + l) rule, where n is the principal quantum number and l is the azimuthal quantum number. If two orbitals have the same (n + l) value, the orbital with the lower n value is filled first.

Explanation

The half-life of a radioactive substance is the time it takes for half of the substance to decay. After each half-life:

At the end of 1 half-life (4 months), 50% of the substance remains. At the end of 2 half-lives (8 months), 25% of the substance remains, meaning 75% (three-fourths) of the substance has decayed. Thus, it takes 8 months for three-fourths of the substance to decay.

Explanation

Astatine, Francium, and Tritium are radioactive elements:

Astatine is a halogen with no stable isotopes.

Francium is an alkali metal, highly unstable and radioactive. Tritium is a radioactive isotope of hydrogen. Zirconium is not radioactive. It is a stable, non-radioactive metal widely used in industries like nuclear reactors and construction.

Explanation

Option (c) is correct: Article 350-A of the Indian Constitution directs that every state should endeavor to provide adequate facilities for instruction in the mother tongue at the primary stage of education. Options (a), (b) and (d) are incorrect:

Article 349 of the Indian Constitution deals with laws related to language. For 15 years after the Constitution’s commencement, any bill or amendment related to language must receive the President’s prior approval, which is given after considering recommendations from the Commission and the report of the Committee constituted under Article 344. Article 350 of the Indian Constitution ensures that individuals can submit grievances to any authority in the Union or State in a language they’re comfortable with. This provision promotes inclusivity and accessibility, recognizing India’s linguistic diversity and ensuring that language doesn’t become a barrier in seeking justice or redressal Article 351 directs the promotion of the Hindi language and aims to make it a unifying language for India by enriching its vocabulary and usage. It does not deal with the issue of primary education in the mother tongue.

Explanation

The Mekong-Ganga Cooperation (MGC) is a regional initiative aimed at enhancing cultural, economic, and tourism ties among member countries. It was launched in 2000 and includes six countries: India, Thailand, Myanmar, Cambodia, Laos, and Vietnam. The project focuses on areas such as tourism, education, culture, and transportation, rather than irrigation, hydroelectric power, or defense.

Explanation

A is matched with 2: Neutrino is a particle with almost zero mass and no electric charge, making it the correct match for zero mass. B is matched with 3: Quarks are fundamental particles with fractional charges, such as +2/3 or -1/3. C is matched with 1: Positrons, the antimatter counterparts of electrons, possess fractional spin, matching this characteristic. D is matched with 4: Photons are elementary particles of light with an integral spin of 1, classifying them as bosons. Direction: The following item consists of two statements. One labeled as the ‘Assertion (A)’ and the other as "Reason (R). You have to answer this item using the code given below: (2000)

Explanation

Assertion (A) is true: Anticyclonic conditions are characterized by high atmospheric pressure and sinking air, which leads to clear skies and low temperatures. These conditions are com-mon in winter, especially in northern India after a cyclonic rain from western disturbances. Reason (R) is true: Winter rainfall in northern India, such as the Western Disturbances, is the result of cyclonic (low-pressure) conditions. However, this rain also creates conditions of anticyclonic activity. R correctly explains A: Cyclonic activities beyond the Indian border bring rain to India in winter. This creates a high Pressure area with light winds radiating outwards. This wind creates anticyclonic activity in northern India. Thus, Reason (R) is the correct explanation of Assertion (A).

Explanation

Statement 1 is correct: As of 2001, India’s total installed power generation capacity was approximately 95,000 MW, according to reports from the Central Electricity Authority (CEA). This included contributions from thermal, hydroelectric, nuclear, and renewable energy sources. As of June 2023-24, the installed capacity has risen to around 146,190 MW.

Statement 2 is incorrect: As of 2001 and even today, nuclear power contributes only around 1-3% (not 15%) of the total electricity generation. The installed nuclear capacity is approximately 7,480 MW, which is a minor fraction of the total energy mix. India’s nuclear expansion has been slow due to regulatory challenges, safety concerns, and the high cost of nuclear plants.

Statement 3 is incorrect: Hydroelectricity accounted for about 25-30% of India’s electricity generation in 2001, not 40%. While hydroelectricity was once a dominant source of power in India, its share has been gradually declining as thermal and renewable energy sources expanded. Currently, hydroelectricity accounts for only about 10-15% of India’s total power generation.

Statement 4 is incorrect: In 2001, thermal power plants (coal, oil, and natural gas) contributed about 65-70% of India’s total power generation, not 80%. Thermal power remains the back-bone of India’s energy sector but has never accounted for such a high percentage. Currently, thermal power contributes around 70-75% of total power generation. While close to 80%, the exact figure fluc-tuates due to the increasing contribution of renewable energy sources like solar and wind.