UPSC Civil Services Examination (Prelims) Science & Technology Hard Previous Year Questions

Consider the following statements about Mission Sudarshan Chakra of India:

1. It aims to enhance India’s air defence, ballistic missile defence and aerial offensive capabilities.
2. This Mission is being designed to enhance rapid, precise, and powerful defence responses, reinforcing India’s strategic autonomy.
3. One of the aims of this Mission is to cover all public places of India by an expanded nationwide security shield by 2035.
   Which of the statements given above is/are correct?

‘X’, born in the UK, was conferred the Nobel Prize in 2025. He was a professor in an American university when this prize was announced. Identify ‘X’:

Consider the following statements, with respect to the AI Impact Summit, 2026 held in New Delhi:

1. The Summit’s intellectual framework was based on three foundational Sutras: People, Planning, and Progress.
2. The Preamble of the Summit stresses Democratising AI Resources, which acknowledges the Charter for Democratic Diffusion of AI as a binding framework to support locally relevant innovation and strengthen resilient AI ecosystems while respecting national laws.
3. The New Delhi Declaration on AI Impact was structured around seven Chakras (Pillars), which included Access for Social Empowerment, AI for Science, and Secure and Trusted AI. Which of the statements given above is/are correct?

An explosion takes place at a certain distance from an army camp. As soon as the sensor in the camp receives the sound of the explosion, a drone starts flying towards the spot of explosion. The drone clicks a picture from the spot and the camp receives it at the same time. Immediately another drone starts flying to the spot and it also sends a picture as soon as it reaches the spot. The two pictures were received at 5:02 PM and 5:05 PM, respectively. If the speed of the drones is 30 m/s, at what time did the explosion take place? Assume that the speed of sound is 300 m/s.

Consider the following statements with regard to involvement of private entities in India's space programme:

1. The Indian National Space Promotion and Authorisation Centre (IN-SPACe) is an autonomous agency formed to facilitate participation of private entities.
2. Agnikul Cosmos launched the world's first flight using 3D-printed rocket engine.
3. Skyroot Aerospace has developed liquid fuel for GSLV.
   Which of the statements given above is/are correct?

Which of the following statements about DHRUV64 is/are correct?

1. It is the third chip fabricated under the DIR-V Programme with an overall aim to enable the creation of microprocessors for India.
2. It is India's first homegrown 1.0 GHz, 64-bit dual-core microprocessor.

Select the answer using the code given below:

Which of the following statements regarding the features of blockchain technology are correct?

1. Records stored in the database may be made visible to relevant stakeholders without risk of alteration.
2. Copies of the entire database are stored on multiple computers on a network, syncing within seconds.
3. Consortium blockchain is a blend of public and private blockchains allowing selective data access.
4. Mathematical algorithms make it impossible to change or delete any data once recorded and accepted.
   Select the answer using the code given below:

Which of the following statements about Rare Earth Elements (REEs) and Critical Minerals is/are correct?

1. Modern technological innovations including Artificial Intelligence, robotics and space exploration extensively utilise Rare Earth Elements (REEs).
2. China has the highest share in mining of REEs followed by India.
3. The Government of India launched the National Critical Mineral Mission (NCMM) in 2025 to establish a robust framework for self-reliance in the critical mineral sector.
4. Rare Earth Elements are a set of 13 metallic elements.
   Select the answer using the code given below:

With reference to the Visible Light Communication (VLC) technology, which of the following statements is/are correct?

1. VLC uses electromagnetic spectrum wavelengths 375 to 780 nm.
2. VLC is known as long-range optical wireless communication.
3. VLC can transmit large amounts of data faster than Bluetooth.
4. VLC has no electromagnetic interference.
   Select the correct answer using the code given below:

Which of the following statements with regard to stealth technology is/are correct?

1. Stealth objects have a very small radar cross-section and are coated with Radar Absorbing Material.
2. Stealth objects can be detected using specific frequencies.
3. Stealth objects are coated with metamaterials to increase the scattering of electromagnetic radiation.
   Select the answer using the code given below:

Consider the following statements:

1. These vaccines are antibiotics that are not effective against drug-resistant bacteria.
2. Dependence on antibiotics as vaccines becomes ineffective against drug-resistant bacteria.
3. Some are novel antigens that are not effective against drug-resistant bacteria and do not cause an allergic reaction.
4. These vaccines have no side effects and are not effective against drug-resistant bacteria.
   Which of the statements given above is/are correct?
   (From page_019: actual Q42 is about vaccines vs antibiotics. The actual extracted text reads: 'Consider the following statements regarding vaccines: 1. These vaccines are antibiotics... Select the correct answer')

Consider the following statements:

1. Genetic changes can be introduced in the cells that produce eggs or sperms of a prospective parent.
2. A person's genome can be edited before birth at the early embryonic stage.
3. Human induced pluripotent stem cells can be injected into the embryo of a pig.
   Which of the statements given above is/are correct?

'The experiment will create a super-equilateral triangle that has sides one million kilometres long.' According to the given description, the experiment is referring to:
(a) Voyager-2
(b) New Horizons
(c) LISA Pathfinder
(d) Evolved LISA

With reference to carbon nanotubes, consider the following statements:

1. They can be used as carriers of drugs and antigens in the human body.
2. They can be used in biochemical sensors.
3. Carbon nanotubes are biodegradable.
4. Carbon nanotubes are non-biodegradable.
   Which of the statements given above is/are correct?

In the context of recent advances in human reproductive technology, Artificial Intelligence can effectively do which of the following?
(a) fertilization of egg in vitro by the donor sperm
(b) genetic modification of sperm producing cells
(c) development of functional embryo
(d) prevention of mitochondrial diseases in offspring

Consider the following statements:

1. Ballistic missiles are jet-propelled at subsonic speeds throughout their flights, while cruise missiles are rocket-powered only in the initial phase of flight.
2. Agni-V is a medium-range supersonic cruise missile, while BrahMos is a solid-fuelled intercontinental ballistic missile.
   Which of the statements given above is/are correct?

In which of the following are hydrogels used?

1. Controlled drug delivery in patients
2. Mobile air-conditioning systems
3. Preparation of industrial lubricants

Select the correct answer using the code given below:

Consider the following statements:

Statement-I: Giant stars live much longer than dwarf stars.

Statement-II: Compared to dwarf stars, giant stars have a greater rate of nuclear reactions.

Which one of the following is correct in respect of the above statements?

With reference to radioisotope thermoelectric generators (RTGs), consider the following statements:

1. RTGs are miniature fission reactors.
2. RTGs are used for powering the onboard systems of spacecrafts.
3. RTGs can use Plutonium-238, which is a by-product of weapons development.

Which of the statements given above are correct?