UPSC Mains Science & Technology
Previous Year Questions (PYQs)

What is the technology being employed for electronic toll collection on highways? What are its advantages and limitations? What are the proposed changes that will make this process seamless? Would this transition carry any potential hazards?

The world is facing an acute shortage of clean and safe freshwater. What are the alternative technologies which can solve this crisis? Briefly discuss any three such technologies citing their key merits and demerits.

Discuss several ways in which microorganisms can help in meeting the current fuel shortage.

Each year a large amount of plant material, cellulose, is deposited on the surface of Planet Earth. What are the natural processes this cellulose undergoes before yielding carbon dioxide, water and other end products?

How is S-400 air defence system technically superior to any other system presently available in the world?

The Nobel Prize in Physics of 2014 was jointly awarded to Akasaki, Amano and Nakamura for the invention of Blue LEDs in 1990s. How has this invention impacted the everyday life of human beings?

How is science interwoven deeply with our lives? What are the striking changes in agriculture triggered off by the science-based technologies?

COVID-19 pandemic has caused unprecedented devastation worldwide. However, technological advancements are being availed readily to win over the crisis. Give an account of how technology was sought to aid management of the pandemic.

Can overuse and free availability of antibiotics without Doctor's prescription, be contributors to the emergence of drug-resistant diseases in India? What are the available mechanisms for monitoring and control? Critically discuss the various issues involved.

What do you understand by fixed dose drug combinations (FDCs)? Discuss their merits and demerits.

What do you understand by Umpire decision review in cricket? Discuss its various components. Explain how silicon tape on the edge of a bat may fool the system?

What is an FRP composite material? How are they manufactured? Discuss their applications in aviation and automobile industry

Distinguish between a Fast Breeder Reactor (FBR) and a thermal nuclear reactor. In the context of first indigenously developed prototype FBR at Kalpakkam, explain the term 'criticality'. What are its implications for clean energy future of our country ?

Mention salient features of 'Mission Drishti'. Discuss the imaging techniques used in the satellite launched on 3rd May 2026. Why it is being considered world's first satellite of its kind ?

The fusion energy programme in India has steadily evolved over the past few decades. Mention India's contributions to the international fusion energy project – International Thermonuclear Experimental Reactor (ITER). What will be the implications of the success of this project for the future of global energy?

India aims to become a semiconductor manufacturing hub. What are the challenges faced by the semiconductor industry in India? Mention the salient features of the India Semiconductor Mission.

What is the main task of India's third moon mission which could not be achieved in its earlier mission? List the countries that have achieved this task. Introduce the subsystems in the spacecraft launched and explain the role of the 'Virtual Launch Control Centre' at the Vikram Sarabhai Space Centre which contributed to the successful launch from Sriharikota.

What is India's plan to have its own space station and how will it benefit our space programme?

Discuss the work of 'Bose-Einstein Statistics' done by Prof. Satyendra Nath Bose and show how it revolutionized the field of Physics.

With growing energy needs should India keep on expanding its nuclear energy programme? Discuss the facts and fears associated with nuclear energy.

India has achieved remarkable successes in unmanned space missions including the Chandrayaan and Mars Orbiter Mission, but has not ventured into manned space missions, both in terms of technology and logistics? Explain critically

Give an account of the growth and development of nuclear science and technology in India. What is the advantage of fast breeder reactor programme in India?

Discuss India's achievements in the field of Space Science and Technology. How the application of this technology has helped India in its socio-economic development?

What do you understand by "Standard Positioning System" and "Precision positioning system" in the GPS era? Discuss the advantage India perceives from its ambitious IRNSS programme employing just seven satellites.

Scientific research in Indian universities is declining, because a career in science is not as attractive as are business professions, engineering or administration, and the universities are becoming consumer-oriented. Critically comment.

What is agentic Artificial Intelligence (AI) ? Explain its working. Describe its applications with suitable examples. Discuss the advantages, risks and challenges associated with agentic AI systems.

Introduce the concept of Artificial Intelligence (AI). How does AI help clinical diagnosis? Do you perceive any threat to privacy of the individual in the use of AI in healthcare?

Discuss the advantage and security implication of cloud hosting of servers vis-a-vis in house machine based hosting for government business.

What are the areas of prohibitive labour that can be sustainably managed by robots? Discuss the initiatives that can propel the research in premier research institutes for substantive and gainful innovation.

What is digital signature? What does its authentication mean? Giver various salient built-in features of a digital signature.

How does the 3D printing technology work? List out the advantages and disadvantages of the technology.

What are asteroids? How real is the threat of them causing extinction of life? What strategies have been developed to prevent such a catastrophe?

Launched on 25th December, 2021, James Webb Space Telescope has been much in the news since then. What are its unique features which make it superior to its predecessor Space Telescopes? What are the key goals of this mission? What potential benefits does it hold for the human race?

How does nanotechnology offer significant advancements in the field of agriculture? How can this technology help to uplift the socioeconomic status of farmers?

What do you understand by nanotechnology and how is it helping in health sector?

Why is nanotechnology one of the key technologies of the 21st century? Describe the salient features of Indian Government's Mission on Nanoscience and Technology and the scope of its application in the development process of the country.

Explain by giving two examples, how biotechnology has helped the Indian farmers in processing their perishable crops.

How can India achieve energy independence through clean technology by 2047? How can biotechnology play a crucial role in this endeavour?

What is the basic principle behind vaccine development? How do vaccines work? What approaches were adopted by the Indian vaccine manufacturers to produce COVID-19 vaccines?

What are the research and developmental achievements in applied biotechnology/? How will these achievements help to uplift the poorer sections of the society?

How can biotechnology improve the living standards of farmers?

Why is there so much activity in the field of biotechnology in our country? How has this activity benefitted the field of biopharma?

Stem cell therapy is gaining popularity in India to treat a wide variety of medical conditions including leukaemia, Thalassemia, damaged cornea and several burns. Describe briefly what stem cell therapy is and what advantages it has over other treatments?

What is the present world scenario of intellectual property rights with respect to life materials? Although, India is second in the world to file patents, still only a few have been commercialized. Explain the reasons behind this less commercialization.

How is the government of India protecting traditional knowledge of medicine from patenting by pharmaceutical companies?

India's Traditional Knowledge Digital Library (TKDL), which has a database containing formatted information on more than 2 million medicinal formulations is proving a powerful weapon in the country's fight against erroneous patents. Discuss the pros and cons of making this database publicly available under open-source licensing.

In a globalized world, Intellectual Property Rights assume significance and are a source of litigation. Broadly distinguish between the terms—Copyrights, Patents and Trade Secrets.

Bring out the circumstances in 2005 which forced amendment to section 3(d) in the Indian Patent Law, 1970. Discuss how it has been utilized by the Supreme Court in its judgment rejecting Novratis' patent application for 'Glivec.' Discuss briefly the pros and cons of the decision.