Important topics and their relevance in UPSC CSE exam for September 28, 2025. If you missed the September 27, 2025, UPSC CSE exam key from the Indian Express, read it here.Preliminary Examination: Current events of national importance.Mains Examination: General Studies-II: Government policies and interventions, Awareness in the fields of IT, Achievements of Indians in science & technology; indigenization of technology and developing new technology.What’s the ongoing story: In a major boost to telecommunication infrastructure, Prime Minister Narendra Modi on Saturday inaugurated BSNL’s ‘Swadeshi’ 4G stack, marking India’s entry into a coveted league of nations that manufacture telecom equipment.Key Points to Ponder:— What is ‘G’ in 4G?— 1G to 5G and further: What changes with each ‘G’?— What is a 4G mobile network?— What is the Digital Bharat Nidhi?— What is 5G technology, and how is it different?— Which network generation is known for supporting IoT (Internet of Things) and ultra-low latency applications?— What is the significance of the ‘Swadeshi’ 4G stack for India’s technological self-reliance?— What are the opportunities and challenges associated with the large-scale deployment of indigenous telecom technology in India?Key Takeaways:Story continues below this ad— Modi, who launched the facility on the occasion of the Bharat Sanchar Nigam Limited’s silver jubilee, also commissioned more than 97,500 mobile 4G towers, including 92,600 4G technology sites of the telecom service provider.— These towers have been built at a cost of around Rs 37,000 crore with ‘swadeshi’ (indigenous) technology, he said.— While lauding the BSNL and its partners’ dedication, Modi said the launch of the ‘Swadeshi’ 4G stack marked India’s entry into a league of nations such as Denmark, Sweden, South Korea, and China, which manufacture homegrown telecom equipment.— Stating that when telecom services like 2G, 3G, and 4G were introduced globally and India remained dependent on foreign technology for these services, Modi said, “Now, India is advancing towards becoming a global telecom manufacturing hub.” The PM said the expansion of 4G technology will directly benefit over two crore people nationwide. Do You Know:Story continues below this ad— According to officials news agency PTI spoke to, the India-made 4G network is cloud-based, energy-efficient, and designed for seamless upgrades to 5G. The rollout, part of BSNL’s silver jubilee celebrations, is aimed at connecting over 26,700 previously unserved villages, including 2,472 in Odisha, and benefit nearly two million new subscribers. Many of these towers are solar-powered, making them the country’s largest cluster of green telecom sites.— From generation one (1G) to the fifth, each generation of telecom technology has sought to change for the better the way humans interact with each other and the world around them. — High speed, high quality, high capacity voice and data services – that’s the promise that 4G, the network brought with it around 2010. Standard 4G came with five to seven times faster speeds than 3G.— Compared to 3G, a phone on a 4G network got quicker response to its requests (lower latency). This is what made our phones more like hand-held computing devices.Other Important Articles Covering the same topic:Explained: The “G” in 4GPrevious year UPSC Prelims Question Covering similar theme:Story continues below this ad(1) Which of the following is/are the aims/aims of the “Digital India” Plan of the Government of India? (UPSC CSE 2018)1. Formation of India’s own Internet companies like China did.2. Establish a policy framework to encourage overseas multinational corporations that collect Big Data to build their large data centers within our national geographical boundaries.3. Connect many of our villages to the Internet and bring Wi-Fi to many of our schools, public places and major tourist centers.Select the correct answer using the code given below: (a) 1 and 2 only (b) 3 only(c) 2 and 3 only (d) 1, 2 and 3 Story continues below this adIndia’s pledge to resolve ‘legal issues’ around N-power is easier said than doneSyllabus:Preliminary Examination: Current events of national and international importance.Mains Examination: General Studies-II, III: Government policies and interventions; Infrastructure: Energy, Indigenization of technology and developing new technology. What’s the ongoing story: Amid renewed efforts to clinch a trade deal with the US, Commerce Minister Piyush Goyal said in New York on Wednesday (September 24) that India’s energy security goals will have a “very high element of US involvement” in the years to come.Key Points to Ponder:— Read about India’s civil nuclear program.— Read about the Civil Liability for Nuclear Damage Act, 2010 (CLNDA) and Atomic Energy Act 1962. Story continues below this ad— What is the 1997 Convention on Supplementary Compensation for Nuclear Damage?— What are small modular reactors (SMRs)?— How SMRs can help address the power needs of India’s growing data centre industry?— What are the benefits and issues associated with the involvement of private companies in India’s nuclear energy sector?Key Takeaways:— Flagging India’s interest in small modular reactor (SMR) innovations in the US, Goyal – who is leading a team of Indian trade negotiators who are in the US to bring trade negotiations back on track – said both countries will also continue to work together and deepen cooperation in the nuclear energy sector, and hinted at certain legal issues that “needed to be resolved” at India’s end.Story continues below this ad— This includes addressing the liability concerns that have hindered nuclear energy growth between the two countries. That’s, however, easier said than done. — As Goyal spoke in New York, the legislative groundwork is currently underway in New Delhi for multiple amendments in the two overarching laws governing the country’s atomic energy sector, which now aim to align these legislations with legal provisions globally.— This, in turn, is expected to address festering investor concerns and set the stage for a progressive opening up of India’s civil nuclear sector, nearly two decades after the historic Indo-US nuclear deal was signed. ALSO READ | UPSC Issue at a Glance | Turmoil in Nepal: GenZ Protest and India-Nepal Relations— The first amendment is an easing of the provisions in India’s nuclear liability law called the Civil Liability for Nuclear Damage Act, 2010 (CLNDA), which sought to create a mechanism for compensating victims from damages caused by a nuclear accident, and allocating liability and specifying procedures for compensation. This has subsequently been cited as an impediment by foreign equipment vendors such as US-based Westinghouse Electric and French nuclear company Framatome on the grounds that this legislation channellises operators’ liability to suppliers through a provision called the right of recourse of the operator.Story continues below this ad— A set of around 11 legal amendments are now being worked out for the CLNDA, of which two are key. One is an amendment aimed at diluting a specific provision – Section 17 (b) of the CLNDA, which is seen to be at odds with similar nuclear liability legislations enacted worldwide.— The second major amendment in the works is aimed at enabling private companies to enter nuclear power plant operations in India, could also set the stage for foreign companies to potentially take a minority equity exposure in upcoming nuclear power projects. — Hitherto, atomic energy has been one of India’s most closed sectors. The set of legal amendments are being seen as a reform push that could help leverage the commercial potential of the Indo-US civil nuclear deal, nearly two decades after it was inked. New Delhi is also keen to package this as part of a broader trade and investment outreach with Washington DC, which could eventually culminate with a trade pact that is currently under negotiation.— Amendments to the second key legislation – the Atomic Energy Act 1962 – are being initiated to enable private companies, and possibly even foreign players at a later stage, to enter nuclear generation as operators, which is currently restricted to only state-owned companies such as NPCIL or NTPC Ltd. — The amendments in the CLNDA would effectively bring India’s nuclear liability legislative framework in line with the provisions of the 1997 Convention on Supplementary Compensation for Nuclear Damage (CSC), which sought to establish a worldwide liability regime. — Under CSC, a country that is a party to either the 1963 Vienna Convention or the 1960 Paris Convention could automatically become a party to the CSC, while a country that was not a party to either of these conventions could also become a party to the CSC if its national law on nuclear liability were to be in compliance with the provision of the CSC and its annexures.— India, not being a party to the Vienna or the Paris Conventions, signed the CSC on October 29, 2010 on the basis of its national law namely the CLND Act and ratified it on February 4, 2016, thereby becoming a ‘State Party’ to the CSC. The tweaks now proposed in the CLND Act would aim to align it further with the CSC provisions, officials indicated.Do You Know:— SMRs are small reactors offering 30-300 MWe power output per unit, and are seen as effective in not just producing base load power (where thermal is seen as important), but also amongst renewables as a more carbon-neutral source.— SMRs are conceptualised in such a way that their systems and components are manufactured in a controlled factory environment and then transported straight to the project site to be installed, which optimises the construction lead time and cuts down the cost of these projects -— two big concerns with regard to traditional large reactor projects.— They have potential deployment advantages like reduced size of the Emergency Planning Zone (ring fenced areas around the project site) and passive safety system, rendering them relatively safer than larger reactor-based projects. Other Important Articles Covering the same topic:Knowledge Nugget: How is Nuclear Energy Mission and Small Modular Reactors relevant for UPSC Exam?UPSC Prelims Practice Question Covering similar theme:(2) Consider the following statements with reference to the small modular reactors:1. Small modular reactors offer 30-300 MWe power output per unit.2. Presently, Two SMR projects have reached the operational stage globally.Which of the statements given above is/are not correct?(a) 1 only(b) 2 only(c) Both 1 and 2(d) Neither 1 nor 2 GOVT & POLITICSHimachal cold desert enters UNESCO biosphere reserve listSyllabus:Preliminary Examination: Current events of national and international importance.Mains Examination: General Studies-II, III: Important International institutions, agencies and fora- their structure, mandate, Conservation, environmental pollution and degradation. What’s the ongoing story: The Cold Desert Biosphere Reserve (CDBR) in Himachal Pradesh, along with 25 other biosphere reserves across several countries, has been included in World Network of Biosphere Reserves (WNBR) by the UNESCO, a global recognition that places the 7,770-sq km area spread across the state’s Lahaul-Spiti district on the international conservation map. With this addition, India now has 13 biospheres listed in WNBR.Key Points to Ponder:— What are the constitutional provisions for the protection of biodiversity in India?— What is a Biosphere Reserve? What are the 3 zones of a biosphere reserve?— Read about the Cold Desert Biosphere Reserve.— What is the World Network of Biosphere Reserves (WNBR)?— What are the Biosphere Reserves in India?— What is the ecological and socio-cultural significance of the inclusion of the Cold Desert Biosphere Reserve in the WNBR?— What is the Man and the Biosphere (MAB) Programme?— What is the flagship species in conservation planning?— Map work: Locate Cold Desert Biosphere Reserve, Pin Valley National Park, Kibber Wildlife Sanctuary, and Chandratal Wetland on a map.Key Takeaways:— “UNESCO designates 26 new biosphere reserves across 21 countries — the highest number in 20 years. The WNBR now includes 785 sites in 142 countries, with an additional one million sq km of natural areas brought under protection since 2018 — equivalent to the size of Bolivia,” UNESCO said in a statement.— The decision to include India’s Cold Desert Biosphere Reserve in the WNBR was taken at the 37th session of UNSECO’s International Coordinating Council of the Man and the Biosphere (MAB) held in Paris Saturday, Union Environment Minister Bhupender Yadav said in a post on X.— Spread in the Trans-Himalayan region, the reserve encompasses the entire Spiti Wildlife Division and adjoining areas of the Lahaul Forest Division, including Baralacha Pass, Bharatpur, and Sarchu with altitudes ranging from 3,300 to 6,600 m. ALSO READ | UPSC celebrates 100 years: ‘Civil servants are context specialists. We connect the dots’: Sanjeev Chopra, former director of LBSNAA— It integrates Pin Valley National Park, Kibber Wildlife Sanctuary, Chandratal Wetland, and the Sarchu plains, encompassing windswept plateaus, glacial valleys, alpine lakes, and high-altitude desert making it one of the coldest and driest ecosystems in WNBR.— The Cold Desert is zoned into three parts — core (2,665 sq km), buffer (3,977 sq km), and transition (1,128 sq km) — balancing conservation, sustainable use, and community participation. Ecologically, it harbours 655 herbs, 41 shrubs, and 17 tree species, including 14 endemics and 47 medicinal plants crucial to the Sowa Rigpa/Amchi system. Its wildlife includes 17 mammal and 119 bird species, with the snow leopard as the flagship species, supported by a robust prey base of more than 800 blue sheep in Spiti valley. The fauna also includes Himalayan ibex and Himalayan wolf. The 7,770-sq km area is spread across Lahaul-Spiti district. Its wildlife includes the snow leopard as the flagship species.— Around 12,000 inhabitants live in scattered villages, practising traditional pastoralism, yak and goat herding, barley and pea farming, and Tibetan herbal medicine, knowledge sustained through Buddhist monastic traditions and community councils that regulate the use of fragile alpine resources, as per a statement by UNECCO.— “As India’s first high- altitude cold desert biosphere reserve, it highlights the urgent need to safeguard mountain ecosystems facing tourism pressures and climate change,” it added.— Welcoming the development, Amitabh Gautam, PCCF (Wildlife) and Chief Wildlife Warden of Himachal Pradesh, said the designation would boost international research collaborations, promote responsible eco-tourism, and strengthen climate resilience efforts in the Himalayas. Do You Know:— The Man and the Biosphere (MAB) programme is UNESCO’s flagship initiative for biodiversity conservation and sustainable development, focussing on improving people’s relationships with their ecosystems.— The MAB programme is an intergovernmental scientific initiative that seeks to build a scientific foundation for improving the relationship between people and their ecosystems.— The MAB programme formulated the concept of biosphere reserves in 1975, which deals with the conservation of ecosystems and the genetic resources contained therein. A notable feature of biosphere reserves is the inclusion of local communities in it. — The World Network of Biosphere Reserves is a dynamic and participatory network of exceptional places maintained by UNESCO’s Man and the Biosphere (MAB) Programme.Other Important Articles Covering the same topic:Biodiversity under threat, what we need to doPrevious year UPSC Prelims Question Covering similar theme:(3) The most important strategy for the conservation of biodiversity together with traditional human life is the establishment of (UPSC CSE 2014)(a) biosphere reserves(b) botanical gardens(c) national parks(d) wildlife sanctuaries(4) Consider the following pairs: (UPSC CSE 2013)1. Nokrek Biosphere Reserve : Garo Hills2. Logtak (Loktak) Lake : Barail Range3. Namdapha National Park : Dafla HillsWhich of the above pairs is/are correctly matched?(a) 1 only(b) 2 and 3 only(c) 1, 2 and 3(d) None OPINIONUPSC @ 100: The story of India’s top recruiterSyllabus:Preliminary Examination: Indian Polity and Governance – Constitution, Political System.Mains Examination: General Studies-II: Constitution of India, functions and responsibilities of various Constitutional Bodies. What’s the ongoing story: Shyamlal Yadav writes- “When the Constitution came into effect in India on January 26, 1950, so did some institutions that enabled the foundation of a newly democratic nation. One such institution was the Union Public Service Commission (UPSC), located at Dholpur House on Shahjahan Road in New Delhi.”Key Points to Ponder:— What are the constitutional provisions with regard to public service commissions?— How do the Macaulay Committee (1854) and the Lee Commission (1924) shape India’s civil services?— What is the composition of the Union Public Service Commission?— What is the significance of UPSC as a constitutional body in sustaining India’s democratic governance?— Read about various committees’ and commissions’ recommendations for reform in UPSC?— What are the challenges faced by the UPSC and state public commissions?— What systemic reforms are required in recruitment, training, and service ethics?Key Takeaways:— “At the time it was founded on October 1, 1926, under the Government of India Act, 1919, the UPSC was known as the Public Service Commission. Before its current name, between 1937 and January 26, 1950, it was called the Federal Public Service Commission (FPSC). On October 1 this year, the highest recruiter of officials to the Indian government will enter its centenary year.”— “A constitutional body, its mandate under Article 320 (outlines the functions of Public Service Commissions) is “to conduct examinations for appointments to the services of the Union and …State respectively”.— “Today, the UPSC mostly holds written exams (usually the two-tier prelims and mains) and interviews (called personality tests).”— “UPSC’s roots date back to the arrival of the East India Company in India as a “traditional trading concern” in the 1600s. As a “traditional trading concern”, its employees — writers, and junior and senior merchants — were purely mercantile servants, appointed and paid according to their individual merits for decades. In the second half of the 18th century, especially after the Company’s victories in the Battle of Plassey in 1757 and the Battle of Buxar in 1764, it realised its new role — to rule India.”— “Around this time, Governor Generals Warren Hastings (from 1773 to 1785), Lord Wellesley (from 1798 to 1805) and Lord Cornwallis (from 1786 to 1793) had reshaped the bureaucracy in British India.”ALSO READ | Knowledge Nugget: National Makhana board — A must-know for UPSC exam— “By 1858, the character of the Company and its civil servants had changed. To manage a rich empire like India efficiently, the Company had started feeling the need to appoint bureaucrats. Before this, its administrative machinery was essentially based on the structure of the Mughal-era, though the Company kept refining its administrative machinery over time.”— “The Macaulay Committee of 1854 was a huge leap forward in the direction of modern-day bureaucracy. In 1855, a Civil Service Commission came into existence in Britain. By 1858, its jurisdiction was extended to the Indian Civil Service (ICS). At first, recruitments to the Commission were done via the direct route — through a written test and, if needed, an interview. After the First World War (1914-1918), a Staff Selection Board (SSB) was set up to manage this.”— “However, entry to the Commission would remain out of bounds for Indians till 1922. Two years after the ICS exams started being held in India from 1922 onwards, in 1924, the Lee Commission recommended early establishment of a Public Service Commission in the country. From 1926 onwards, the SSB handed over the responsibility of recruitments to this very Public Service Commission. Sir Ross Barker served as its chairperson till 1932.”— “A new proposal under the Government of India Act, 1935, established a Commission for both the federation and each province or group of provinces. By the time this new format — the Federal Public Service Commission (FPSC) — rolled out in on April 1, 1937, and Sir Eyre Gordon took over from Sir David Petrie as its chairperson, India was merely a decade away from Independence. Already, the Constitution was being debated and provisions were being framed for an independent recruiter of civil servants in India.”— “When India became independent on August 15, 1947, the FPSC was headed by its first Indian chief, H K Kripalani. After him, R N Banerjee headed the Commission from 1949 to 1955. During his tenure,the Constitution came into effect, as did two change of names — the FPSC was now the UPSC, while the ICS was renamed as the Indian Administrative Service (IAS).”— “The UPSC’s Dholpur House headquarters, where it shifted in 1952, too has an interesting backstory. Belonging to the erstwhile Raja of Dholpur, Udai Bhan Singh, it was transferred to the government after Independence, when the Raja decided to merge his state with the Union of India. The Raja was then appointed as the Rajpramukh (similar to a Governor) of the Matsya Union, a state created with the merger of some princely states after Independence. This building continues to be the house of UPSC.”— “Over the years, the UPSC instituted several reforms within. It has also disclosed several details related to its exams after Right to Information (RTI) queries were filed, though it resisted the law at first.”— “Various commissions and committees — the first Administrative Reforms Commission of 1966 (headed by Morarji Desai, and later by K Hanumanthaiah), the Thorat panel of 1967 (headed by Lt Gen S P P Thorat), the Kothari panel of 1976 (headed by Daulat Singh Kothari), the Satish Chandra panels of 1989 and 1990, the Alagh Committee of 2001 (headed by Y K Alagh), the P C Hota panel of 2004 and the Arun Nigavekar panel of 2012 — too have shaped the UPSC’s current recruitment pattern.”Other Important Articles Covering the same topic:UPSC: From colonial roots to constitutional body FRONT38 dead in stampede at Vijay campaign rally in Tamil NaduSyllabus:Preliminary Examination: Current events of national importance.Mains Examination: General Studies-III: Disaster and disaster management.What’s the ongoing story: A campaign rally for Tamil star-turned-politician Vijay ended in a stampede that killed at least 38 people – among them 16 women and eight children – and left over 150 hospitalised across Karur and Trichy. At least half a dozen victims are critical and the toll could go up, officials said.Key Points to Ponder:— What is a stampede?— What are the factors leading to stampedes?— What are the NDMA guidelines for crowd management in India?— What should be done for effective crowd management and preventing stampedes?Key Takeaways:— Officials said the chaos began shortly after 7.30 pm, behind the van from which Vijay was speaking. Dozens of supporters had climbed a tree to get a better view. When its branches gave way, they fell onto the tightly packed crowd about 50 meters away. The sudden crash triggered a panic that rippled through the audience, crushing men, women, and children.— Ambulances forced their way through even as Vijay continued speaking, unaware of the scale of the unfolding disaster. He left the stage soon after and travelled back to Chennai, arriving around 11 pm. Police sources said he was briefed about the deaths when he stopped in Trichy en route to catch a flight. He did not address the media but spoke with local police and TVK functionaries about the incident.— The Union Home Ministry has sought a report from the state on the incident. Home Minister Amit Shah also spoke to the Governor and Chief Minister and assured all possible help from the Centre.Do You Know:— Wenguo Weng and others define a stampede as “an impulsive mass movement of a crowd that often results in injuries and deaths” (“Review of analyses on crowd-gathering risk and its evaluation methods”, 2023).— According to Illiyas and others, “Stampede is the surge of individuals in a crowd, in response to a perceived danger or loss of physical space. It often disrupts the orderly movement of crowds resulting in irrational and dangerous movement for self-protection leading to injuries and fatalities”.— K M Ngai and others classify two types of stampedes on the basis of movement — unidirectional or turbulent (“Human Stampedes: A Systematic Review of Historical and Peer-Reviewed Sources”, 2009). Unidirectional stampede events may occur when a crowd moving in the same direction encounters a sudden positive or negative change in force which alters its movement. A positive force can be a “sudden stop” situation like a bottleneck and blocked exit, whereas a negative force would be something like a broken barrier or column which sends a group of people tumbling. Turbulent stampede events can occur in situations with uncontrolled crowds, induced panic, or crowds merging from numerous directions.— Crowd management is a crucial tool for ensuring the safety of citizens during various types of mass gatherings. Unfortunately, stampedes still occur. According to nidm.gov.in, such unfortunate events happen due to a lack of (i) understanding of crowd behaviour, (ii) coordination, (iii) clear roles & responsibilities of various stakeholders, and (iv) proper planning on the part of organizers. Other Important Articles Covering the same topic:UPSC Issue at a Glance | How to prevent stampedes at mass gatherings — 4 Key Questions You Must Know for Prelims and MainsUPSC Mains Practice Question Covering similar theme:Crowd management is an important tool for the safety of citizens especially at religious places. Unfortunately, crowd disasters still happen. What are the major reasons behind such disasters? Suggest strategies to avoid crowd disasters.ALSO IN NEWSGovt adds 2 more years to Attorney General’s tenureThe Centre Saturday extended the tenure of Attorney General for India R Venkataramani by two more years. A September 26 notification by the Ministry of Law and Justice said that the President is pleased to re-appoint Venkataramani as AG for a further period of two years, with effect from October 1, 2026.IIT Madras researchers create cancer tissue bank for customised Indian patient therapiesImagine growing tumour cells extracted from a patient in the laboratory. Instead of doing trial and error with the patient, researchers can test the therapies in the lab and help clinicians choose the appropriate treatment. Such an innovation is happening at a cancer genome and tissue bank developed by researchers from the Indian Institute of Technology-Madras. From developing new genetic panels for cancers, to identifying new biomarkers from blood tests that can detect cancer, and laboratory-based organoids that can be used to test which treatment is likely to work best for a cancer patient, researchers have been working on nearly 7,000 tissue samples of all types of cancers from hospitals across India.HC questions govt order on BC quota, posts matter for Oct 8 The Telangana High Court Saturday evening, while hearing a writ petition challenging the government order (GO MS no 9 issued on September 26, 2025) that allowed 42 per cent reservation for the Backward Classes in local bodies, questioned the lack of Governor’s assent for the bill and urgency with which the GO was issued, and sought detailed counter from the state by October 8. The division bench of Justice Abhinand Kumar Shavili and Justice B Vijaysen Reddy was dealing with a House motion that questioned the breach of the 50 per cent ceiling in reservations mandated by Supreme Court judgments. After hearing the petitioners and the Advocate General, who appeared for the state, the bench noted that the matter be posted on October 8. Prelims Answer Key 1. (b) 2. (d) 3. (a) 4. (a)Subscribe to our UPSC newsletter. Stay updated with the latest UPSC articles by joining our Telegram channel – Indian Express UPSC Hub, and follow us on Instagram and X. Anniversary Special: Read the UPSC Essentials September 2025 special edition, celebrating two years of the magazine! Share your views and suggestions at manas.srivastava@indianexpress.com