UPSC (IAS) 2020 Prelims exam is scheduled for 4 October. Check section-wise important questions & answers on Science & Technology from past papers. After analysing the latest UPSC Syllabus and previous years’ papers, we observed that Science & Technology is one of the important sections of this exam and at least 10 to 15 questions are expected in UPSC Prelims 2020 exam. In this article, we have provided all the questions from previous years papers of UPSC Prelims (2019, 2018, 2017). After going through these questions, students preparing for UPSC (IAS) 2020 can easily understand the level of questions which have been asked in UPSC Prelims.
UPSC Prelims 2020: Some Important Points from Analysis of Previous Years' Papers
⇒ Generally questions asked in UPSC Prelims can be best represented by the image given below
⇒ Trends shows that 10 to 15 questions are expected this year
⇒ Topics based on Environments issues (like Global Warming) are often interlinked with Science & Technology and are important
⇒ Any latest development & technology which has impacts on India and the world is very important.
⇒ You can learn more details after going through questions from previous years’ questions of Science & Technology
⇒ You can access similar important articles from the links given below
UPSC 2020 (IAS) Prelims: Check Important Questions For Preparation of History
UPSC 2020 (IAS) Prelim: Check Important Questions from Geography Section
UPSC IAS Syllabus 2020: Prelims & Mains Syllabus of Civil Services Exam
UPSC 2020 (IAS) Prelims: Check Important Questions for Preparation of International Relations
UPSC 2020 (IAS) Prelims: Check Important Questions for Preparation of Economy Section
UPSC 2020 (IAS) Prelims: Check Important Questions from Environment & Ecology Section
UPSC 2020 (IAS) Prelims: Check Important Questions for Preparation of Indian Polity Section
UPSC IAS Prelims 2020: Questions Based on Science & Technology from 2019 Paper
Question: With reference to communication technologies, what is/are the difference / differences between LTE (Long-Term Evolution) and VoLTE (Voice over Long-Term Evolution)?
1. LTE 'is commonly marketed as 3G and VoLTE is commonly marketed as advanced 3G.
2. LTE is data-only technology and VoLTE is voice-only technology.
Select the correct answer using the code given below.
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer: d
Question: In the context of digital technologies for entertainment, consider the following statements:
1. In Augmented Reality (AR) , a simulated environment is created and the physical world is completely shut out.
2. In Virtual Reality (VR), images generated from a computer are projected onto real-life objects or surroundings.
3. AR allows individuals to be present in the world and improves the experience using the camera of smart-phone or PC.
4. VR closes the world, and transposes an individual, providing complete immersion experience.
Which of the statements given above is/are correct?
(a) 1 and 2 only
(b) 3 and 4
(c) 1, 2 and 3
(d) 4 only
Answer: b
Question: With reference to the recent developments in science, which one of the following statements is not correct?
(a) Functional chromosomes can be created by joining segments of DNA taken from cells of different species.
(b) Pieces of artificial functional DNA can be created in Laboratories.
(c) A piece of DNA taken out from an animal cell can be made to replicate outside a living cell in a laboratory.
(d) Cells taken out from plants and animals can be made to undergo cell division in laboratory Petri dishes.
Answer: a
Question: Consider the following statements:
A digital signature is
1. an electronic record that identifies the certifying authority issuing it
2. used to serve as a proof of identity of an individual to access information or server on the Internet.
3. an electronic method of signing an electronic document and ensuring that the original content is unchanged
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 and 3 only
(c) 3 only
(d) 1, 2 and 3
Answer: d
Question: In the context of wearable technology, which of the following tasks is/are accomplished by wearable devices?
1. Location identification of a person
2. Sleep monitoring of a person
3. Assisting the hearing impaired person
Select the correct answer using the code given below.
(a) 1 only
(b) 2 and 3 only
(c) 3 only
(d) 1, 2 and 3
Answer: d
Question: 'RNA interference (RNAi)' technology has gained popularity in the last few years. Why?
1. It is used in developing gene-silencing therapies.
2. It can be used in developing therapies for the treatment of cancer.
3. It can be used to develop hormone replacement therapies.
4. It can be used to produce crop plants that are resistant to viral pathogens.
Select the correct answer using the code given below.
(a) 1, 2 and 4
(b) 2 and 3
(c) 1 and 3
(d) 1 and 4 only
Answer: a
Question: Recently, scientists observed the merger of giant 'blackholes' billions of light-years away from the Earth. What is the significance of this observation?
(a) 'Higgs boson particles' were detected.
(b) 'Gravitational waves' were detected.
(e) Possibility of intergalactic space travel through 'wormhole' was confirmed.
(d) It enabled the scientists to understand 'singularity'.
Answer: b
Question: Which of the following are the reasons for the occurrence of multi-drug resistance in microbial pathogens in India?
1. Genetic predisposition of some people
2. Taking incorrect doses of antibiotics to cure diseases
3. Using antibiotics in livestock farming
4. Multiple chronic diseases in some people
Select the correct answer using the code given below.
(a) 1 and 2
(b) 2 and 3 only
(e) 1, 3 and 4
(d) 2, 3 and 4
Answer: a
Question: What is Cas9 protein that is often mentioned in news?
(a) Molecular scissors used in targeted gene editing
(b) A biosensor used in the accurate detection of pathogens in patients
(c) A gene that makes plants pest-resistant
(d) A herbicidal substance synthesized in genetically modified crops
Answer: a
Question: Which one of the following statements is not correct?
(a) Hepatitis B virus is transmitted much like HIV.
(b) Hepatitis B, unlike Hepatitis C, does not have a vaccine.
(c) Globally, the number of people infected with Hepatitis B and C viruses are several times more than those infected with HIV.
(d) Some of those infected with Hepatitis Band C viruses do not show the symptoms for many years.
Answer: b
Question: In the context of which of the following do some scientists suggest the use of the cirrus cloud thinning technique and the injection of sulphate aerosol into the stratosphere?
(a) Creating the artificial rains in some regions
(b) Reducing the frequency and intensity of tropical cyclones
(c) Reducing the adverse effects of solar wind on the Earth
(d) Reducing the global warming
Answer: d
Question: In the context of which one of the following are the terms 'pyrolysis and plasma gasification' mentioned?
(a) Extraction of rare earth elements
(b) Natural gas extraction technologies
(c) Hydrogen fuel-based automobiles
(d) Waste-to-energy technologies
Answer: d
Question: In the context of proposals to the use of hydrogen-enriched CNG (H-CNG) as fuel for buses in public transport, consider the following statements:
1. The main advantage of the use of H-CNG is the elimination of carbon monoxide emissions.
2. H-CNG as a fuel reduces carbon dioxide and hydrocarbon emissions.
3. Hydrogen up to one-fifth by volume can be blended with CNG as fuel for buses.
4. H-CNG makes the fuel less expensive than CNG.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 and 3 only
(c) 4 only
(d) 1, 2, 3 and 4
Answer: b
Question: Why are dewdrops not formed on a cloudy night?
(a) Clouds absorb the radiation released from the Earth's surface.
(b) Clouds reflect back the Earth's radiation.
(c) The Earth's surface would have the low temperature on cloudy nights.
(d) Clouds deflect the blowing wind to ground level.
Answer: b
Question: Consider the following:
1. Carbon monoxide
2. Methane
3. Ozone
4. Sulphur dioxide
Which of the above are released into the atmosphere due to the burning of crop/biomass residue?
(a) 1 and 2 only
(b) 2, 3 and 4 only
(c) 1 and 4 'only
(d) 1, 2, 3 and 4
Answer: d
Question: In India, the use of carbofuran, methyl parathion, phorate and triazophos is viewed with apprehension. These chemicals are used as
(a) Pesticides in agriculture
(b) Preservatives in processed foods
(c) Fruit-ripening agents
(d) Moisturising agents in cosmetics
Answer: a
UPSC IAS Prelims 2020: Questions Based on Science & Technology from 2018 Paper
Question: With reference to the Indian Regional Navigation Satellite System (IRNSS), consider the following statements :
1. IRNSS has three satellites in geostationary and four satellites in geosynchronous orbits.
2. IRNSS covers entire India and about 5500 sq. km beyond its borders.
3. India will have its own satellite navigation system with full global coverage by the middle of 2019.
Which of the statements given above is/are correct ?
(a) 1 only
(b) 1 and 2 only
(c) 2 and 3 only
(d) None
Answer. a
Question: Consider the following phenomena :
1. Light is affected by gravity.
2. The Universe is constantly expanding.
3. Matter warps its surrounding space-time.
Which of the above is/are the prediction/predictions of Albert Einstein's General Theory of Relativity, often discussed in media ?
(a) 1 and 2 only
(b) 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer. c
Question: Consider the following pairs :
Terms sometimes seen in news Context /Topic
1. Belle II experiment - Artificial Intelligence
2. Blockchain technology - Digital/Cryptocurrency
3. CRISPR — Cas9 - Particle Physics
Which of the pairs given above is/are correctly matched ?
(a) 1 and 3 only
(b) 2 only
(c) 2 and 3 only
(d) 1, 2 and 3
Answer. b
Question: Which of the following statements best describes "carbon fertilization"?
(a) Increased plant growth due to increased concentration of carbon dioxide in the atmosphere
(b) Increased temperature of Earth due to increased concentration of carbon dioxide in the atmosphere
(c) Increased acidity of oceans as a result of increased concentration of carbon dioxide in the atmosphere
(d) Adaptation of all living beings on Earth to the climate change brought about hr the increased concentration of carbon dioxide in the atmosphere
Answer. a
Question: When the alarm of your smartphone rings in the morning, you wake up and tap it to stop the alarm which causes your geyser to be switched on automatically. The smart mirror in your bathroom shows the day's weather and also indicates the level of water in your overhead tank. After you take some groceries from your refrigerator for making breakfast, it recognises the shortage of stock in it and places an order for the supply of fresh grocery items. When you step out of your house and lock the door, all lights, fans, geysers and AC machines get switched off automatically. On your way to office, your car warns you about traffic congestion ahead and suggests an alternative route, and if you are late for a meeting, it sends a- message to your office accordingly.
In the context of emerging communication technologies, which one of the following term" best applies to the above scenario?
(a) Border Gateway Protocol
(b) Internet of Things
(c) Internet Protocol
(d) Virtual Private Network
Answer.b
Question: With reference to solar power production in India, consider the following statements:
1. India is the third largest in the world in the manufacture of silicon wafers used in photovoltaic units.
2. The solar power tariffs are determined by the Solar Energy Corporation of India.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer.d
Question: In which of the following areas can GPS technology be used?
1. Mobile phone operations
2. Banking operations
3. Controlling the power grids
Select the correct answer using the code given below:
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer.d
Question: Consider the following statements:
1. The Earth's magnetic field has reversed every few hundred thousand years.
2. When the Earth was created more than 4000 million years ago, there was 54% oxygen and no carbon dioxide.
3. When living organisms originated, they modified the early atmosphere of the Earth.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer.c
Question: The terms ‘Wanna Cry, Petya and Eternal Blue' sometimes mentioned in the news recently are related to
(a) Exo-planets
(b) Crypto-currency
(c) Cyber attacks
(d) Mini satellites
Answer.c
Question: "3D printing" has applications in which of the following?
1. Preparation of confectionery items
2. Manufacture of bionic ears
3. Automotive industry
4. Reconstructive surgeries
5. Data processing technologies
Select the correct answer using the code given below :
(a) 1, 3 and 4 only
(b) 2, 3 and 5 only
(c) 1 and 4 only
(d) 1, 2, 3, 4 and 5
Answer.d
Question: The identity platform `Aadhaar' provides open "Application Programming Interfaces (APIs)". What does it imply?
1. It can be integrated into any electronic device.
2. Online authentication using iris is possible.
Which of the statements given above is/are correct ?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer.c
Question: With reference to digital payments, consider the following statements:
1. BHIM app allows the user to transfer money to anyone with a UPI-enabled bank account.
2. While a chip-pin debit card has four factors of authentication, BHIM app has only two factors of authentication.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer.a
Question: With reference to India’s satellite launch vehicles, consider the following statements:
1. PSLVs launch the satellites useful for Earth resources monitoring whereas GSLVs are designed mainly to launch communication satellites.
2. Satellites launched by PSLV appear to remain permanently fixed in the same position in the sky, as viewed from a particular location on Earth.
3. GSLV Mk III is a four-staged launch l vehicle with the first and third stages l using solid rocket motors; and the second and fourth stages using liquid rocket engines.
Which of the statements given above is/are correct.?
(a) 1 only
(b) 2 and 3
(c) 1 and 2
(d) 3 only
Answer.a
Question: Consider the following:
1. Birds
2. Dust blowing
3. Rain
4. Wind blowing
Which of the above spread plant diseases?
(a) 1 and 3 only
(b) 3 and 4 only
(c) 1, 2 and 4 only
(d) 1, 2, 3 and 4
Answer.d
UPSC IAS Prelims 2020: Questions Based on Science & Technology from 2017 Paper
Question: Biological Oxygen Demand (BOD) is a standard criterion for
(a) Measuring oxygen levels in blood
(b) Computing oxygen levels in forest ecosystems
(c) Pollution assay in aquatic ecosystems
(d) Assessing oxygen levels in high altitude regions
Answer. c
Question: Consider the following pairs:
| Commonly used/consumed materials |
Unwanted or controversial chemicals likely to be found in them |
| 1. Lipstick |
Lead |
| 2. Soft drinks |
Brominated vegetable oils |
| 3. Chinese fast food |
Monosodium glutamate |
Which of the pairs given above is/are correctly matched?
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer. d
Question: Organic Light Emitting Diodes (OLEDs) are used to create digital display in many devices. What are the advantages of OLED displays over Liquid Crystal displays?
1. OLED displays can be fabricated on flexible plastic substrates.
2. Roll-up displays embedded in clothing can be made using OLEDs.
3. Transparent displays are possible using OLEDs.
Select the correct answer using the code given below
(a) 1 and 3 only
(b) 2 only
(c) 1, 2 and 3
(d) None of the above statements is correct
Answer. c
Question: What is the application of Somatic Cell Nuclear Transfer Technology?
(a) Production of biolarvicides
(b) Manufacture of biodegradable plastics
(c) Reproductive cloning of animals
(d) Production of organisms free of diseases
Answer. c
Question: What is the purpose of 'evolved Laser Interferometer Space Antenna (eLISA)' project?
(a) To detect neutrinos
(b) To detect gravitational waves
(c) To detect the effectiveness of missile defence system
(d) To study the effect of solar flares on our communication systems
Answer. b
Question: Consider the following statements:
1. In tropical regions, Zika virus disease is transmitted by the same mosquito that transmits dengue.
2. Sexual transmission of Zika virus disease is possible.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer. c
Question: The terms 'Event Horizon', 'Singularity', `String Theory' and 'Standard Model' are sometimes seen in the news in the context of
(a) Observation and understanding of the Universe
(b) Study of the solar and the lunar eclipses
(c) Placing satellites in the orbit of the Earth
(d) Origin and evolution of living organisms on the Earth
Answer. a
Question: With reference to agriculture in India, how can the technique of `genome sequencing', often seen in the news, be used in the immediate future?
1. Genome sequencing can be used to identify genetic markers for disease resistance and drought tolerance in various crop plants.
2. This technique helps in reducing the time required to develop new varieties of crop plants.
3. It can be used to decipher the host-pathogen relationships in crops.
Select the correct answer using the code given below:
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer: d
UPSC Exam Calendar 2020 & Best Books Recommended by Toppers for IAS Mains & Prelims Preparation
