UPSC Prelims 2018
Science & Technology Previous Year Questions (PYQs)

Detailed Explanation:

Answer: Option 1 — 1 only

Simple Explanation:

This question tests the basic difference between PSLV and GSLV launch vehicles.

✅ Statement 1 – Correct: PSLV is mainly used to launch Earth observation/remotely sensed satellites into Polar or Sun-Synchronous Orbits, while GSLV is designed to launch heavy communication satellites into Geosynchronous Transfer Orbit (GTO).

❌ Statement 2 – Incorrect: Satellites launched by PSLV do not remain fixed over one point on Earth. They move in Polar/Sun-Synchronous Orbits. Only geostationary satellites appear stationary in the sky.

❌ Statement 3 – Incorrect: GSLV Mk III (LVM3) is a three-stage launch vehicle, not a four-stage vehicle. It consists of two solid strap-on boosters, one liquid core stage, and one cryogenic upper stage.

📝 Short Notes: PSLV & GSLV

• PSLV (Polar Satellite Launch Vehicle) is mainly used for Earth observation and Sun-Synchronous Orbit (SSO) missions.

• GSLV is designed to place communication satellites into Geosynchronous Transfer Orbit (GTO).

• LVM3 (formerly GSLV Mk III) is a three-stage heavy-lift launch vehicle with a cryogenic upper stage.

• Cryogenic engines use liquid hydrogen (LH₂) and liquid oxygen (LOX) for high efficiency.

• PSLV is known as ISRO's "workhorse launcher" due to its high reliability.

• LVM3 successfully launched Chandrayaan-2, Chandrayaan-3, and the OneWeb satellite missions.

• Geostationary satellites remain fixed relative to Earth, while Polar satellites continuously move over different regions.

Detailed Explanation:

The correct answer is 1, 2 and 3 (Option 3). Einstein's General Theory of Relativity states that gravity bends light, matter curves space-time, and its equations also allow an expanding universe, which was later confirmed by observations.

General Theory of Relativity (1915) explains gravity as the curvature of space-time caused by mass and energy. It predicts phenomena like gravitational lensing, black holes, gravitational waves, and the expanding universe.

Detailed Explanation:

The correct answer is Cyberattacks (Option 3). WannaCry and Petya are ransomware attacks that encrypt data and demand payment. EternalBlue is a cyber exploit that was used to spread the WannaCry attack by exploiting a Microsoft Windows vulnerability.

Ransomware is a type of malware that locks or encrypts a user's data and demands a ransom for restoring access. Major cyberattacks like WannaCry (2017) highlighted the importance of regular software updates and strong cybersecurity practices.

Detailed Explanation:

The correct answer is An American anti-missile system (Option 3). THAAD (Terminal High Altitude Area Defense) is a missile defense system developed by the United States to intercept and destroy short, medium, and intermediate-range ballistic missiles during their final phase of flight.

THAAD is designed to intercept ballistic missiles both inside and outside the Earth's atmosphere. It is an important part of the U.S. missile defense network and has been deployed in countries such as South Korea and Saudi Arabia.

Detailed Explanation:

The correct answer is 2 only (Option 2). Belle II is a particle physics experiment, not Artificial Intelligence. Blockchain is the technology behind cryptocurrencies. CRISPR-Cas9 is a gene-editing technology used in biotechnology, not particle physics.

Blockchain is a decentralized digital ledger that records transactions securely and transparently. It is the core technology behind cryptocurrencies like Bitcoin and has applications in finance, supply chains, and digital identity.

Detailed Explanation:

Answer: Option 4 — 1, 2 and 3

GPS (Global Positioning System) is a satellite-based navigation system that provides precise geolocation and time information, making it useful across diverse applications beyond just navigation.

✅ Statement 1 – Correct: GPS is integral to mobile phone operations for location tracking, navigation apps, and location-based services like ride-hailing and food delivery.
✅ Statement 2 – Correct: GPS provides precise time-stamping for banking transactions, ensuring accurate record-keeping and synchronization across banking networks, and enables ATM location services.
✅ Statement 3 – Correct: GPS is crucial for synchronizing power grid operations by providing accurate time stamps for measurements, which is essential for grid stability and preventing blackouts.

📝 Short Notes: GPS Technology Applications

• GPS (Global Positioning System): A satellite-based navigation system owned by the US government, consisting of 24+ satellites orbiting Earth.
• Primary Function: Provides geolocation (latitude, longitude, altitude) and precise time information to GPS receivers anywhere on Earth.
• Timing Applications: GPS satellites carry atomic clocks that provide nanosecond-level time accuracy, critical for telecommunications, banking, power grids, and stock markets.
• Navigation Uses: Aviation, maritime, vehicle navigation, surveying, mapping, and military operations.
• Location-Based Services: Mobile apps, emergency services (911/112), asset tracking, agriculture (precision farming), and weather forecasting.
• Other Global Systems: GLONASS (Russia), Galileo (EU), BeiDou (China), and NavIC/IRNSS (India's regional system).

Detailed Explanation:

Answer: Option 2 — 2 only

GM Mustard (DMH-11) is a genetically modified hybrid variety of Brassica juncea developed by Delhi University's Centre for Genetic Manipulation of Crop Plants. It has been engineered with barnase-barstar genes to enable cross-pollination and hybridization for increased yield, not for pest-resistance.

✅ Statement 1 – Incorrect: GM mustard does not contain genes for pest-resistance; it is engineered for hybridization using barnase-barstar gene system, not Bt genes from soil bacteria.
✅ Statement 2 – Correct: GM mustard contains genes (barnase, barstar, and bar genes) that facilitate cross-pollination and hybridization, enabling hybrid seed production.
✅ Statement 3 – Incorrect: GM mustard was developed by Delhi University's Centre for Genetic Manipulation of Crop Plants (CGMCP), not jointly by IARI and Punjab Agricultural University.

📝 Short Notes: GM Mustard (DMH-11)

• Full Name: Dhara Mustard Hybrid-11 (DMH-11), a genetically modified variety of Brassica juncea.
• Developed by: Centre for Genetic Manipulation of Crop Plants (CGMCP), Delhi University under Prof. Deepak Pental.
• Genetic Modification: Uses barnase-barstar gene system borrowed from soil bacterium Bacillus amyloliquefaciens for male sterility and fertility restoration.
• Purpose: Enables cross-pollination in naturally self-pollinating mustard to produce high-yielding hybrids; increases yield by 25-30%.
• Key Genes: Bar gene (herbicide tolerance), barnase gene (male sterility), barstar gene (fertility restoration).
• Not Bt Crop: Unlike Bt cotton/brinjal, GM mustard does not have pest-resistance traits; it is purely for hybrid development.
• Regulatory Status: Approved by GEAC (Genetic Engineering Appraisal Committee) in 2017 but faced public and legal challenges.

Detailed Explanation:

Answer: Option 4 — 1, 2, 3, 4 and 5

3D printing (additive manufacturing) has revolutionized multiple industries by enabling the creation of complex three-dimensional objects from digital files. All five applications mentioned—confectionery items, bionic ears, automotive parts, reconstructive surgery implants, and specialized components for data processing hardware—are well-documented uses of 3D printing technology.

✅ Statement 1 – Correct: 3D printing is used in the food industry to create intricate and customized confectionery items like chocolates and candies with precise designs.
✅ Statement 2 – Correct: Researchers have successfully used 3D printing to manufacture bionic ears with integrated electronics for people with hearing impairments.
✅ Statement 3 – Correct: The automotive industry extensively uses 3D printing for rapid prototyping, custom parts manufacturing, and production of vehicle components.
✅ Statement 4 – Correct: 3D printing is widely used in reconstructive surgeries to create patient-specific implants, prosthetics, and surgical guides tailored to individual anatomy.
✅ Statement 5 – Correct: 3D printing is utilized to manufacture specialized components and hardware parts for data processing technologies and computer systems.

📝 Short Notes: 3D Printing (Additive Manufacturing)

• Definition: 3D printing is a process of creating three-dimensional solid objects from a digital file by adding material layer by layer, hence called additive manufacturing.
• Basic Process: Involves computer-aided design (CAD) software to create digital models, which are then sliced into thin layers and printed using various materials like plastics, metals, ceramics, or even biological materials.
• Medical Applications: Custom prosthetics, dental implants, surgical instruments, anatomical models for surgery planning, bio-printed tissues and organs (experimental stage), and patient-specific implants.
• Industrial Applications: Rapid prototyping in automotive and aerospace industries, manufacturing of complex parts, tooling, and production of end-use components.
• Consumer Applications: Customized jewelry, toys, household items, fashion accessories, and personalized products.
• Emerging Applications: Food printing (chocolates, pasta, pizza), construction (3D printed houses), bioprinting (organs and tissues), and electronics manufacturing.
• Advantages: Design flexibility, waste reduction, customization, rapid prototyping, and ability to create complex geometries impossible with traditional manufacturing.

Detailed Explanation:

Answer: Option 1 — 1 only

IRNSS (Indian Regional Navigation Satellite System), also known as NavIC (Navigation with Indian Constellation), is India's independent regional navigation satellite system. Among the three statements, only the first statement correctly describes the satellite configuration of IRNSS.

✅ Statement 1 – Correct: IRNSS has three satellites in geostationary orbits (positioned at fixed points above the equator) and four satellites in geosynchronous orbits (inclined geosynchronous orbits at approximately 29° inclination).

❌ Statement 2 – Incorrect: IRNSS covers the entire India and extends approximately 1500 km beyond its borders (primary service area), not 5500 sq. km. The extended service area covers a much larger region from 30°S to 50°N latitude and 30°E to 130°E longitude.

❌ Statement 3 – Incorrect: IRNSS/NavIC is a regional navigation system, not a global navigation system. It provides coverage over India and surrounding regions only. India does not have a satellite navigation system with full global coverage as of 2019 or currently.

📝 Short Notes: IRNSS/NavIC

• Full Form: Indian Regional Navigation Satellite System (IRNSS), operational name NavIC (Navigation with Indian Constellation)
• Constellation: 7 satellites total - 3 in Geostationary Orbit (GEO) and 4 in Geosynchronous Orbit (GSO)
• Primary Service Area: India and region extending up to 1500 km from its boundary
• Extended Service Area: Region between 30°S to 50°N latitude and 30°E to 130°E longitude
• Operational Since: 2018 (all 7 satellites became operational)
• Applications: Terrestrial, aerial and marine navigation, disaster management, vehicle tracking, fleet management, integration with mobile phones, precise timing, mapping and geodetic data capture
• Administered by: Indian Space Research Organisation (ISRO)
• Ground Segment: IRNSS Spacecraft Control Facility (IRSCF) at Hassan and Bhopal, IRNSS Range and Integrity Monitoring Stations (IRIMS) at multiple locations, and Navigation Control Centres

Detailed Explanation:

Answer: Option 2 — Internet of Things

The scenario describes an interconnected ecosystem where everyday devices (smartphone, geyser, smart mirror, refrigerator, car, etc.) communicate with each other autonomously, exchange data over a network, and perform automated tasks based on triggers without requiring direct human intervention. This is the defining characteristic of the Internet of Things (IoT), which connects physical objects embedded with sensors, software, and network connectivity to collect and exchange data.

Why other options are incorrect:
❌ Option 1 – Border Gateway Protocol: BGP is a routing protocol used to exchange routing information between autonomous systems on the internet; it is not related to device intercommunication.
❌ Option 3 – Internet Protocol: IP is a foundational protocol for addressing and routing packets across networks, but does not encompass the intelligent device-to-device communication described.
❌ Option 4 – Virtual Private Network: VPN is a technology for creating secure, encrypted connections over public networks, not for enabling smart device ecosystems.

📝 Short Notes: Internet of Things (IoT)

• Definition: IoT is a network of physical objects embedded with sensors, software, and connectivity that enables them to collect, exchange, and act on data autonomously.
• Key Components: Sensors/devices, connectivity (Wi-Fi, Bluetooth, cellular), data processing platforms, and user interfaces.
• Applications: Smart homes (automated lighting, thermostats), smart cities (traffic management, waste management), healthcare (wearable health monitors), agriculture (precision farming), and industrial automation.
• Benefits: Increased efficiency, real-time monitoring, predictive maintenance, energy conservation, and enhanced user convenience.
• Challenges: Security vulnerabilities, privacy concerns, interoperability issues between different devices/standards, and data management complexity.
• Examples in India: Smart cities mission, precision agriculture initiatives, connected vehicles, and smart grid projects for electricity distribution.

Detailed Explanation:

Answer: Option 3 — Both 1 and 2

The availability of open Application Programming Interfaces (APIs) for Aadhaar enables developers and organizations to integrate Aadhaar-based authentication and verification services into various electronic devices and applications. This architectural design allows for seamless integration across platforms and supports multiple authentication methods including biometric verification.

✅ Statement 1 – Correct: Open APIs allow Aadhaar to be integrated into any electronic device such as smartphones, tablets, Point of Sale (PoS) terminals, and other digital platforms, enabling developers to build Aadhaar-enabled applications.
✅ Statement 2 – Correct: Aadhaar's biometric authentication system supports online authentication using iris scans (along with fingerprints and facial recognition), making secure identity verification possible through the available APIs.

📝 Short Notes: Aadhaar and APIs

• Aadhaar: A 12-digit unique identity number issued by the Unique Identification Authority of India (UIDAI) to all Indian residents based on biometric and demographic data.
• Open APIs: Application Programming Interfaces that allow third-party developers to integrate Aadhaar services into their applications and devices without requiring proprietary access.
• Authentication Methods: Aadhaar supports multiple authentication modes including demographic (name, age, address), One-Time Password (OTP), and biometric (fingerprint, iris, facial recognition).
• e-KYC Services: Aadhaar APIs enable electronic Know Your Customer (e-KYC) services for instant verification in banking, telecom, and other sectors.
• Integration Capabilities: APIs facilitate integration across diverse platforms including mobile apps, web portals, ATMs, PoS devices, and IoT-enabled devices.
• Security Features: All API transactions are encrypted and follow strict security protocols to protect user privacy and prevent unauthorized access.

Detailed Explanation:

Answer: Option 4 — WTO

India enacted the Geographical Indications of Goods (Registration and Protection) Act, 1999 to comply with its obligations under the TRIPS (Trade-Related Aspects of Intellectual Property Rights) Agreement of the WTO. TRIPS mandates all WTO member countries to provide legal protection for Geographical Indications, which identify products originating from specific geographical locations whose qualities or reputation are essentially attributable to that origin.

📝 Short Notes: Geographical Indications in India

• GI Act, 1999: Enacted to comply with TRIPS Agreement (Articles 22-24) under WTO framework
• Definition: GI identifies goods as originating from a specific territory where quality, reputation, or other characteristics are essentially attributable to geographical origin
• Duration: GI registration is valid for 10 years and can be renewed indefinitely
• Examples: Darjeeling Tea (first Indian GI), Basmati Rice, Kanchipuram Silk, Tirupati Laddu, Kashmir Pashmina
• Authority: Controller General of Patents, Designs and Trademarks under the Department for Promotion of Industry and Internal Trade (DPIIT) administers GI registration
• Benefits: Legal protection against unauthorized use, promotes rural and agricultural development, preserves traditional knowledge