UPSC 2018 Science and Technology Questions with Answers
7 previous year UPSC Prelims questions on Science and Technology in the UPSC 2018 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 1–7 of 7 questions
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UPSC 2018Science and Technology · Diseases
Q1. Consider the following 1. Birds 2. Dust blowing 3. Rain 4. Wind blowing Which of the above spread plant diseases?
Explanation
Birds can act as carriers of plant pathogens. As they move through crops, pathogens may stick to their feathers, beaks, or feet, transferring them from infected plants to healthy ones. Dust particles often carry fungal spores or bacterial cells. When dust is blown by the wind, these pathogens can travel to new areas, causing infections in plants far from the original source. Rainwater, particularly during heavy downpours or storms, can facilitate the spread of pathogens. Raindrops pick up pathogens from infected plants or soil and splash them onto healthy plants, promoting disease transmission. Wind plays a significant role in transporting pathogens such as fungal spores, bacteria, or insect vectors contaminated with viruses. This mechanism allows pathogens to infect plants located far from the initial infection site.
Exam tip:
You can try, The "NOT" approach for all statements, this tests the improbability of negating a statement--if denying its impact seems highly unlikely, the statement is plausibly true. For Example: Birds or Rain or Wind NOT Spread plant diseases. Absurd, unlikely. Hence all original are likely true.
UPSC 2018Science and Technology · Information and Communication Technology
Q2. 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:
Explanation
GPS technology uses a network of satellites to pinpoint a user’s location on Earth. By receiving signals from multiple satellites, GPS devices can calculate precise latitude, longitude, and altitude coordinates. This technology has revolutionized navigation, transportation, and many other fields. Options 1 is correct: Smartphones use GPS to determine the user’s precise location which enables location-based services such as navigation, ride-sharing apps, geotagging, and emergency location tracking. Option 2 is correct: Financial institutions use GPS-derived time stamps to record the exact time of transactions, aiding in audit trails and fraud detection. GPS ensures that banking systems across different locations operate in sync, which is crucial for real-time processing and settlements. Options 3 is correct: GPS provides precise time references that are vital for synchronizing the operations of power grids, helping in load balancing and efficient energy distribution.
UPSC 2018Science and Technology · Information and Communication Technology
Q3. 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 the 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 terms best applies to the above scenario?
Explanation
Option (b) is correct: The scenario described is a classic example of the Internet of Things (IoT). IoT refers to a network of interconnected devices that communicate and exchange data with each other to automate tasks and improve efficiency. The smartphone, geyser, smart mirror, refrigerator, and car are all IoT devices.
Option (a),(c) and (d) are incorrect:
Border Gateway Protocol is used to manage how data packets are routed across the internet between different autonomous systems (networks). It is primarily used by internet service providers (ISPs) and large organizations to ensure efficient data routing. Internet Protocol (IP) is a fundamental communication protocol used for transmitting data over the internet. It provides the addressing system (IP addresses) that allows devices to communicate. Virtual Private Network is a technology that creates a secure, encrypted connection over the internet to protect user privacy and data. It is commonly used to access restricted networks or hide online activity.
UPSC 2018Science and Technology · Space and Space Technology
Q4. Consider the following statements: 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 the media?
Explanation
General theory of relativity, is a geometric theory related to gravitation published by Albert Einstein in 1915 and currently defines gravitation in modern physics. A coherent account of gravity as a geometric property of space and time, or four-dimensional spacetime, is provided by general relativity, which generalises special relativity and improves Newton’s law of universal gravitation. In particular, the energy and momentum of all matter and radiation present have a direct relationship to the curvature of spacetime.
Statement 1 is correct: According to General Relativity, light travels along the curved spacetime shaped by the gravity of massive objects. This phenomenon, known as gravitational lensing, has been observed in effects such as Einstein’s Cross and the bending of starlight around the Sun.
Statement 2 is correct: General Theory of Relativity showed that space and time are malleable or flexible, and predicted that our universe was ever expanding.
Statement 3 is correct: The theory of relativity states that massive objects distort spacetime around it. And since photons travel the shortest distance between two points, light appears to be bent when it travels through the distorted spacetime of a massive object.
UPSC 2018Science and Technology · Space and Space Technology
Q5. With reference to India’s satellite launch vehicles, consider the following statements: 1. PSLVs launch the satellite 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 vehicle with the first and third stages using solid rocket motors; and the second and fourth stages using liquid rocket engines. Which of the statements given above is/are correct?
Explanation
Statement 1 is correct: The Polar Satellite Launch Vehicle (PSLV) is primarily used to place satellites in Sun-Synchronous Polar Orbits (SSO), which are ideal for Earth observation, remote sensing, and resource monitoring. The Geosynchronous Satellite Launch Vehicle (GSLV) is used to place communication satellites into Geostationary Transfer Orbit (GTO), from where they move into Geostationary Orbit (GEO) for telecom and broadcasting services.
Statement 2 is incorrect:
Geostationary satellites (which remain fixed over a location) are launched into Geostationary Orbit (GEO) at 35,786 km altitude, usually by GSLV, not PSLV. PSLV typically places satellites in Low Earth Orbit (LEO) or Sun-Synchronous Orbit (SSO), where they move relative to the Earth’s surface.
Statement 3 is incorrect:
GSLV Mk III (now LVM3) is actually a three-stage launch vehicle:
First stage: Two solid rocket boosters (S200) Second stage: A liquid-fueled core stage (L110) Third stage: A cryogenic stage (C25) There is no fourth stage in GSLV Mk III, making the statement incorrect.
Exam tip:
For S2, PSLV places satellites in polar orbits also and not necessarily in geostationary. Hence S2 is overly restrictive and likely false. For S3, When UPSC gives too much technical detail, its easier to manipulate and make it false.
UPSC 2018Science and Technology · Miscellaneous
Q6. 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?
Explanation
Statement 1 is correct: The Earth’s magnetic field has undergone numerous reversals over geological time scales. These geomagnetic reversals occur at irregular intervals averaging approximately every 300,000 years though it varies.
Statement 2 is incorrect: Over 4000 million years ago earth’s early atmosphere lacked oxygen and was primarily composed of gases like methane, ammonia, water vapor, and carbon dioxide. The current level of oxygen (around 21%) accumulated much later due to photosynthetic activity by living organisms.
Statement 3 is correct: Living organisms particularly cyanobacteria played a significant role in modifying the Earth’s early atmosphere by producing oxygen through photosynthesis. This process led to the Great Oxygenation Event around 2.4 billion years ago. This marked a pivotal shift from an oxygen-poor to an oxygen-rich atmosphere, profoundly influencing the evolution of life.
UPSC 2018Science and Technology · Miscellaneous
Q7. ‘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:
Explanation
3D printing, also known as additive manufacturing, is a method of creating a three dimensional object layer-by-layer using a computer simulated design. A 3D item is produced by the additive method of 3D printing, which involves building up layers of material. Options 1 is correct: 3D printing is widely used in the food industry to create intricate designs, especially with edible materials like chocolate and sugar. This technique enables customization and the production of unique shapes that are difficult to achieve with traditional methods. Options 2 is correct: Researchers have successfully used 3D printing to fabricate bionic ears by integrating biological cells with conductive materials. This method not only replicates the structure of a human ear but also enhances its functionality by embedding electronics, potentially improving hearing capabilities.
Option 3 is correct: In the automotive sector, 3D printing is used for rapid prototyping, creating tools, and manufacturing parts. It speeds up the design process, reduces production costs, and enables the creation of lightweight components, which improve vehicle performance and fuel efficiency.
Option 4 is correct: The healthcare sector leverages 3D printing for producing customized implants and prosthetics. In reconstructive surgeries, this technology allows for the creation of patient-specific implants that precisely match the patient’s anatomy, leading to better surgical outcomes.
Option 5 is correct: While 3D plays a significant role in data visualization. For instance, in scientific research, complex data sets can be transformed into tangible 3D models, enhancing the understanding of intricate structures.
Exam tip:
You can try, The "NOT" approach for all statements, this tests the improbability of negating a statement--if denying its impact seems highly unlikely, the statement is plausibly true.
Answer key for these questions
Q
UPSC year
Correct answer
1
2018
(d) 1, 2, 3 and 4
2
2018
(d) 1, 2 and 3
3
2018
(b) Internet of Things
4
2018
(d) 1, 2 and 3
5
2018
(a) 1 only
6
2018
(c) 1 and 3 only
7
2018
(d) 1, 2, 3, 4 and 5
Frequently asked questions
How many previous year UPSC questions are there on Science and Technology?
This page covers 7 previous year UPSC Prelims GS Paper-I questions on Science and Technology in the UPSC 2018 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 2018 Prelims are available for 30 years, from 1996 to 2025. Use the Year filter to practise a single paper.
