UPSC 2020 Science and Technology Questions with Answers
14 previous year UPSC Prelims questions on Science and Technology in the UPSC 2020 Prelims. Choose an option to see the answer and explanation.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
Showing 1–10 of 14 questions
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UPSC 2020Science and Technology · Health
Q1. 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?
Explanation
Gene therapy is the ability to improve genes through the correction of misplaced (mutated) genes or site-specific alterations with therapeutic treatment as the target. A gene abnormality that has been identified in a child or embryo can be corrected using a variety of techniques known as gene therapy. In this instance, genes are injected to treat an illness into a person’s cells and tissues.
Statement 1 is correct: Genetic modifications can be made to germ cells (sperm or eggs) of prospective parents. Techniques like CRISPR/Cas9 allow for precise editing of DNA in these cells, potentially preventing the transmission of genetic diseases to offspring.
Statement 2 is correct: Genome editing technologies, such as CRISPR/Cas9, allow scientists to precisely modify DNA at the early embryonic stage to correct genetic defects. This approach, called germline editing, involves altering the genome of an embryo at its earliest stage of development, ensuring that all cells in the resulting organism carry the change. These genetic modifications are heritable, meaning they can be passed down to future generations. While this technique offers the potential to prevent inherited genetic disorders, it also raises serious ethical concerns, such as the possibility of creating "designer babies" and safety challenges, including the risk of unintended genetic changes (off-target effects) that could cause unforeseen health issues.
Statement 3 is correct: Human induced pluripotent stem cells (iPSCs) have been experimentally integrated into pig embryos to create interspecies chimeras. This research aims to understand developmental biology and explore organ transplantation possibilities, such as growing human-compatible organs in animals.
Exam tip:
Again, "CAN" and "Some" = possibility logic, not absolute. If even one example exist, the statement is likely correct. UPSC uses "can" and "some" to lower the burden of proof harder to eliminate. Hence all statements are likely correct.
UPSC 2020Science and Technology · Diseases
Q2. What is the importance of using Pneumococcal Conjugate Vaccines in India? 1. These vaccines are effective against pneumonia as well as meningitis and sepsis. 2. Dependence on antibiotics that are not effective against drug resistant bacteria can be reduced. 3. These vaccines have no side effects and cause no allergic reactions. Select the correct answer using the code given below:
Explanation
Statement 1 is correct: PCVs protect against infections caused by Streptococcus pneumoniae, which can lead to pneumonia, meningitis, and sepsis. This is particularly important in India, where pneumococcal diseases contribute significantly to child mortality.
Statement 2 is correct: By preventing pneumococcal infections, PCVs decrease the need for antibiotics, thereby mitigating the risk of developing and spreading antibiotic-resistant bacteria.
Statement 3 is incorrect: Like other vaccines, PCVs can have mild side effects such as fever, redness at the injection site, and, in rare cases, allergic reactions. No vaccine is completely free of side effects.
Exam tip:
See, S2 uses "CAN be reduced", hence possibility logic likely true, but S3 uses absolute term "NO SIDE effect". is it possible a vaccine cause no side effect? unlikely hence S3 false.
UPSC 2020Science and Technology · Information and Communication Technology
Q3. With the present state of development, Artificial Intelligence can effectively do which of the following? 1. Bring down electricity consumption in industrial units 2. Create meaningful short stories and songs 3. Disease diagnosis 4. Text-to-Speech Conversion 5. Wireless transmission of electrical energy Select the correct answer using the code given below:
Explanation
Statement 1 is correct: AI-powered systems are used in smart grids and industrial automation to minimize electricity consumption. AI algorithms analyze energy consumption patterns and adjust systems in real-time to reduce waste and improve efficiency.
Statement 2 is correct: AI advancements such as natural language processing (NLP) and generative models like GPT can create meaningful short stories and songs. Tools like OpenAI’s GPT-3 and AI music generators demonstrate the ability to produce creative content that resonates with human audiences. Note: UPSC did not consider this option as correct probably because Generative AI was not so advanced at that time.
Statement 3 is correct: AI is widely used in healthcare for disease diagnosis. Machine learning algorithms analyze medical data such as imaging scans, genetic information, and patient records to detect diseases like cancer, diabetes, and cardiovascular conditions with high accuracy. AI systems like IBM Watson and Google DeepMind are prominent examples.
Statement 4 is correct: AI-powered text-to-speech (TTS) systems such as Google WaveNet and Amazon Polly can convert written text into natural-sounding speech. These systems are widely used in virtual assistants, audiobooks, and accessibility tools for visually impaired individuals.
Statement 5 is incorrect: Wireless transmission of electrical energy is a physical and engineering challenge and not directly related to AI. While AI can optimize energy systems but it does not play a direct role in the wireless transmission of electricity, which relies on technologies like inductive coupling or microwave transmission. Note: Considering the options provided most suitable answer is Option (b).
Exam tip:
Now this question is perfect example of UPSC efforts to counter NOT approach. But see how UPSC even here uses extreme examples, S2 mentions creating meaningful stories and S5 talks about wireless electricity transmission which both are too utopian to be true at present times. They are clearly exaggeration hence likely false.
UPSC 2020Science and Technology · Information and Communication Technology
Q4. With reference to Visible Light Communication (VLC) technology, which of the following statements are correct? 1. VLC uses electromagnetic spectrum wavelengths of 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:
Explanation
Visible Light Communication (VLC) uses visible light for data communication. Optical wireless communications methods include VLC as a subset. Because light-producing equipment (such as indoor/outdoor lamps, TVs, traffic signs, commercial displays, and car headlights/taillights) are utilised everywhere, VLC can be employed as a communications channel for ubiquitous computing.
Statement 1 is correct: Visible Light Communication (VLC) operates within the visible light spectrum which ranges from approximately 375 nm (violet) to 780 nm (red). VLC uses light-emitting diodes (LEDs) to transmit data by modulating light intensity.
Statement 2 is incorrect: VLC is considered a short-range communication technology due to the limitations of light propagation. It is effective over short distances such as within a room or confined space and is not designed for long-range communication like radio frequency (RF) technologies.
Statement 3 is correct: VLC has the potential to transmit data at very high speeds often exceeding the data rates of Bluetooth. VLC can achieve data rates in the range of gigabits per second (Gbps) while Bluetooth typically operates at much lower speeds (up to a few megabits per second).
Statement 4 is correct: VLC operates in the visible light spectrum, which does not interfere with radio frequency (RF) signals. This makes VLC particularly useful in environments where electromagnetic interference (EMI) is a concern such as hospitals, aircraft, and industrial settings.
Exam tip:
For S2, Visible light" inherently suggests shorter reach -- light does not penetrate walls, and gets scattered or blocked easily. VLC uses light think line of sight (like a laser pointer or torchlight) immediately rules out long-range practicality. Hence S2 likely false.
UPSC 2020Science and Technology · Information and Communication Technology
Q5. In India, under cyber insurance for individuals, which of the following benefits are generally covered, in addition to payment for the loss of funds and other benefits? 1. Cost of restoration of the computer system in case of malware disrupting access to one’s computer 2. Cost of a new computer if some miscreant wilfully damages it, if proved so 3. Cost of hiring a specialized consultant to minimize the loss in case of cyber extortion 4. Cost of defence in the Court of Law if any third party files a suit Select the correct answer using the code given below:
Explanation
Statement 1 is correct: Cost of restoration of the computer system in case of malware disrupting access to one’s computer is generally covered under cyber insurance policies. If a malware attack disrupts access to your computer system the insurance can covers the expenses related to restoring the system to its original state.
Statement 2 is incorrect: Cyber insurance policies do not cover physical damage to hardware. They primarily focus on digital and financial losses. If a computer is physically damaged by a miscreant, it would fall under general insurance or property insurance rather than cyber insurance. These insurance policies are primarily focused on addressing losses arising from cybercrimes affecting data and software.
Statement 3 is correct: Cyber insurance often covers the cost of hiring cybersecurity experts, consultants, or negotiators to minimize financial and reputational losses in case of cyber extortion such as ransomware attacks.
Statement 4 is correct: Cyber insurance policies often provide coverage for legal defense costs if a third party initiates a lawsuit related to a cyber incident. This includes expenses such as attorney fees and other legal charges. Example: Bajaj Allianz’s policy covers defense costs arising from claims made by third parties against the insured individual.
Exam tip:
For S2, Cyber insurance primarily covers digital or cyber losses -- hacking, malware, phishing, extortion. Physical damage to hardware (e.g., breaking the computer) is usually covered under electronic equipment or home insurance, not cyber insurance. Hence likely false.
UPSC 2020Science and Technology · Information and Communication Technology
Q6. With reference to "Blockchain Technology" consider the following statements: 1. It is a public ledger that everyone can inspect but which no single user controls 2. The structure and design of blockchain is such that all the data in it is about crypto currency only. 3. Applications that depend on basic features of blockchain can be developed without anybody’s permission. Which of the statements given above is/are correct?
Explanation
Blockchain technology is a decentralized and secure system for recording and verifying transactions across multiple computers. It uses cryptography to link blocks of data together in a chain, making it difficult to alter or tamper with the information. This technology has applications in various fields, including finance, supply chain management, and healthcare.
Statement 1 is correct: Blockchain operates as a decentralized and distributed ledger, allowing all participants to view transactions without granting control to any single user. This transparency and lack of central authority are fundamental characteristics of blockchain technology.
Statement 2 is incorrect: While blockchain gained prominence through cryptocurrencies like Bitcoin, its applications extend far beyond digital currencies. Blockchain’s versatile structure supports various uses, including supply chain management, healthcare data management, and identity verification, among others.
Statement 3 is correct: Public blockchain platforms, such as Ethereum, enable developers to build decentralized applications (dApps) without requiring approval from a central authority. This open-access design promotes innovation and encourages widespread participation within the blockchain ecosystem.
Exam tip:
For S2, The phrase "all the data in crypto currency only" is too absolute and extreme to be true, hence likely false, eliminates options B and C.
UPSC 2020Science and Technology · Nanoscience and Nanotechnology
Q7. When 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 made into artificial blood capillaries for an injured part of the human body. 3. They can be used in biochemical sensors. 4. Carbon nanotubes are biodegradable. Which of the statements given above are correct?
Explanation
Carbon nanotubes are cylindrical structures made of carbon atoms arranged in a hexagonal lattice. They possess exceptional strength, high electrical conductivity, and unique mechanical properties, making them promising materials for applications in electronics, materials science, and nanotechnology.
Statement 1 is correct: Carbon nanotubes (CNTs) have been widely researched for their role in drug delivery systems. Their unique hollow structure allows them to transport therapeutic molecules directly to targeted cells, improving treatment precision and effectiveness. Functionalization of CNTs enhances biocompatibility and minimizes toxicity.
Statement 2 is incorrect: Carbon nanotubes have applications in tissue engineering, including constructing artificial blood vessels. Their mechanical strength and ability to support cell growth make them useful for creating scaffolds that mimic natural capillaries, promoting tissue repair. However, UPSC in its official answer key has not given recognition to this development and marked statement 2 as incorrect.
Statement 3 is correct: Due to their exceptional electrical conductivity, carbon nanotubes are integral to the development of highly sensitive biochemical sensors. These sensors can detect specific biological molecules, contributing to advancements in diagnostics and monitoring technologies.
Statement 4 is correct: Multiple types of microbes, including bacteria and fungi, have the ability to degrade carbon nanotubes (CNTs). Thus carbon nanotubes are very much biodegradable in nature.
Exam tip:
For S2, The phrase can be made into artificial blood capillaries implies real-world medical application, not just lab potential. That’s an extreme generalization of a field still in early-stage trials. This is similar to wireless electricity transfer in Question 68, page 573. Hence more probably false.
UPSC 2020Science and Technology · Space and Space Technology
Q8. The experiment will employ a trio of spacecraft flying in formation in the shape of an equilateral triangle that has sides one million kilometers long, with lasers shining between the craft." The experiment in question refers to
Explanation
Evolved LISA (eLISA) is a planned mission by the ESA for gravitational wave detection. It will detect minute distortions in space-time caused by gravitational waves. Lasers will shine between the spacecraft to measure changes in distance. Two "Daughter" spacecraft and a "Mother" spacecraft make up the eLISA mission. These will form a triangle orbit around the Sun. The two Daughter spacecraft will be joined to the Mother satellite, and the three satellites will form a precision interferometer by 1 million km long laser beams. Options (a), (b) and (c) are incorrect:
Voyager-2: A NASA spacecraft that studied Jupiter, Saturn, Uranus, and Neptune. It was not intended for gravitational wave detection. New Horizons: The first mission to explore Pluto and the Kuiper Belt, focused on planetary exploration rather than detecting gravitational waves. LISA Pathfinder: It was the precursor mission of eLISA that successfully demonstrated the technology required for a space based gravitational wave observatory.
UPSC 2020Science and Technology · Nuclear Technology
Q9. In India, why are some nuclear reactors kept under "IAEA Safeguards" while others are not?
Explanation
IAEA safeguards apply to nuclear reactors using imported uranium as part of India’s international agreements. These safeguards ensure that the imported fuel is strictly used for civilian purposes and not diverted for military use. However, not all nuclear reactors in India are placed under IAEA safeguards. Reactors using domestic uranium are not subject to these safeguards allowing flexibility for strategic programs. By keeping reactors using domestic uranium outside IAEA safeguards, India maintains the flexibility to support its strategic programs without external oversight. As of recent data, out of India’s 22 operational reactors, 14 are under IAEA safeguards because they utilize imported fuel.
Additional insight:
Reactors Using Imported Uranium - Under IAEA Safeguards India imports uranium through civil nuclear cooperation agreements with countries like the U.S., Russia, and France. Reactors using imported uranium must be placed under IAEA safeguards to ensure peaceful usage. Example: Kudankulam Nuclear Power Plant (uses Russian-supplied fuel). Reactors Using Domestic Uranium - Not Under IAEA Safeguards India has natural uranium reserves, but they are insufficient to meet demand. Reactors using domestic uranium remain under sovereign control and are not necessarily under IAEA safeguards. Example: Tarapur (TAPS-1 & 2) and some PHWRs initially used domestic uranium and were not under safeguards.
UPSC 2020Science and Technology · Miscellaneous
Q10. Consider the following activities: 1. Spraying pesticides on a crop field 2. Inspecting the craters of active volcanoes 3. Collecting breath samples from spouting whales for DNA analysis. At the present level of technology, which of the above activities can be successfully carried out by using drones?
Explanation
A drone, technologically, is an unmanned aircraft.
They are formally known as unmanned aerial vehicles (UAVs). A drone is essentially a flying robot that can be remotely piloted or can fly on its own using software-controlled flight plans in embedded systems in conjunction with onboard sensors and GPS.
Statement 1 is correct: Modern agriculture has increasingly adopted drones for the application of pesticides and fertilizers. These drones offer precision in spraying, ensuring uniform coverage and reducing the exposure of farmers to harmful chemicals. For instance, a study published in Springer highlights that drones equipped with advanced sensors and high-resolution cameras can distinguish between healthy and infested crops, allowing for targeted pesticide application.
Statement 2 is correct: Drones equipped with visual and thermal cameras are utilized in geological studies to inspect active volcano craters. They can safely approach hazardous areas, capturing high-resolution images and collecting gas samples. Researchers from the German Research Centre for Geosciences (GFZ) successfully employed drones to study the active Santa Maria volcano in Guatemala.
Statement 3 is correct: Marine biologists have innovated methods to collect biological samples from whales using drones. By flying drones through the spouts of whales, researchers can gather respiratory droplets containing DNA, hormones, and microorganisms without disturbing the animals. This technique was employed in the Ocean Alliance’s SnotBot program.
Answer key for these questions
Q
UPSC year
Correct answer
1
2020
(d) 1, 2 and 3
2
2020
(b) 1 and 2 only
3
2020
(b) 1, 3 and 4 only
4
2020
(c) 1, 3 and 4 only
5
2020
(b) 1, 3 and 4 only
6
2020
(d) 1 and 3 only
7
2020
(c) 1, 3 and 4 only
8
2020
(d) Evolved LISA
9
2020
(b) Some use imported uranium and others use domestic supplies
10
2020
(d) 1, 2 and 3
Frequently asked questions
How many previous year UPSC questions are there on Science and Technology?
This page covers 14 previous year UPSC Prelims GS Paper-I questions on Science and Technology in the UPSC 2020 Prelims, asked from 1996 to 2025. Each has the correct answer and an explanation.
How should I use previous year UPSC questions for Prelims?
Attempt each question first, then open the answer and read the explanation for every option. Repeat by chapter, and track which statements UPSC reuses across years. Previous year questions show the exam pattern and difficulty level.
Which years are covered for Science and Technology?
Questions on Science and Technology in the UPSC 2020 Prelims are available for 30 years, from 1996 to 2025. Use the Year filter to practise a single paper.
