Blockchain, Extended Reality and Other Emerging Technologies

1.Blockchain Technology

• Blockchain as a Distributed Ledger TechnologyImportance 4/5UPSC 2018
  What is blockchain, and in what way is it one kind of Distributed Ledger Technology (DLT)? Understand what a "distributed ledger", a "node" and a "block" mean. Is every DLT a blockchain? Understand why such a system needs no central database.
• Steps in a Blockchain TransactionImportance 3/5
  Understand the order of steps from a requested transaction to a block joining the chain: who creates the block, to whom it is sent, and what the nodes do. Is the "reward for proof of work" step part of every blockchain?
• Hashing and the Linking of BlocksImportance 3/5
  What is a hash? Understand how each block carries the hash of the block before it, and why changing one block exposes tampering. Be clear about what a Merkle tree does, in outline.
• Key Features of BlockchainImportance 5/5UPSC 2020, 2026
  Remember the five features of blockchain (decentralisation, immutability, transparency, security, energy intensity) and the reason behind each. Do all of them hold for every blockchain? Is a permissioned chain visible to all, and does it use as much energy as a public one? Does any single user control a public blockchain? Must all blockchain data be about cryptocurrency? Can anyone build an application on an open chain without permission?
• Public, Private, Consortium and Hybrid BlockchainsImportance 3/5UPSC 2026
  Who may join and validate in a public, a private, a consortium and a hybrid blockchain? Understand the split between permissioned and permissionless chains, and why governments often prefer permissioned ones. Is India's National Blockchain Framework permissioned or permissionless?
• Origin of Blockchain and BitcoinImportance 2/5
  Who introduced blockchain, in which year, and for which digital currency? Remember the earlier idea, and the scientist behind it, that inspired the design.
• Ethereum, Smart Contracts and Decentralised ApplicationsImportance 3/5
  What did Ethereum add to blockchain? Understand what a smart contract is and what it does on its own, and what decentralised applications (DApps) and decentralised finance (DeFi) are.
• Applications of Blockchain and Blockchain-as-a-ServiceImportance 3/5
  Remember the main sector uses of blockchain (finance, healthcare, copyright, supply chain, voting), with one example for each. What is Blockchain-as-a-Service (BaaS), and who provides it?
• National Strategy on Blockchain and Centres of ExcellenceImportance 2/5
  What does the national strategy on blockchain (2021) aim to do? Understand the role of the National Informatics Centre's Centre of Excellence, and remember which states have set up blockchain centres or incubators.
• National Blockchain Framework (Vishvasya, NBFLite, Praamaanik)Importance 3/5
  When was the National Blockchain Framework launched, and what is it? Remember what each part does: Vishvasya, NBFLite, Praamaanik and the National Blockchain Portal. Was it built by one ministry alone, or by a group of institutions?
• Blockchain in Indian Regulation and Public ServicesImportance 2/5
  What is a regulatory sandbox, and what has the Reserve Bank of India (RBI) used one for? May cryptocurrency services be tested in the RBI's sandbox, or only other blockchain applications? Remember named public uses of blockchain: TRAI's use for commercial SMS, the National Informatics Centre's certificate, document and property chains, and Karnataka's drug supply chain.

2.Consensus Mechanisms

• Proof of WorkImportance 3/5
  How do miners compete in Proof of Work, and what do they earn? Understand why it is secure and why it uses so much energy. Why does a blockchain with no central authority need a consensus rule at all? Remember Bitcoin as the standard example.
• Proof of Stake and the Ethereum MergeImportance 3/5
  How are validators chosen in Proof of Stake, and what stops them from cheating? Understand why it uses less energy than Proof of Work. What was the Ethereum Merge, and which mechanism did Ethereum use before and after it? Remember Cardano and Solana as examples.
• Delegated Proof of Stake and Minting Through Smart ContractsImportance 1/5
  What does delegation add to Proof of Stake? Remember EOS and Tron as examples. How do DeFi projects mint new tokens through rules written into smart contracts?

3.Cryptocurrency

• Meaning and Features of CryptocurrencyImportance 4/5UPSC 2016
  What is a cryptocurrency, and what role does cryptography play in it? Understand why it is called decentralised, how it differs from money issued by a government, and what sets its value. On what kinds of exchanges is it traded, and for what purposes is it used?
• How a Cryptocurrency Transaction WorksImportance 2/5
  Follow a payment from A to B: how is it turned into a block, who approves it, and how does it reach the chain? Understand why the record is called indelible and transparent.
• Popular Cryptocurrencies and StablecoinsImportance 2/5
  Remember Bitcoin, Ethereum and Litecoin as examples of cryptocurrencies. What is a stablecoin, and how does it differ from an ordinary cryptocurrency whose price swings?
• Cryptocurrency in India: RBI Stand and Supreme Court RulingImportance 2/5
  What has the RBI said about cryptocurrencies, and what restriction did it place on banks dealing with them? Which court set that restriction aside, and when? Be clear about the difference between the year of the RBI order and the year of the court ruling.
• Cryptocurrency as Legal Tender AbroadImportance 2/5
  Which countries have made Bitcoin legal tender, and does each still keep that status today? What restrictions have China and Russia placed on cryptocurrency use, and has either country eased them since?

4.Non-Fungible Tokens

• Fungible and Non-Fungible AssetsImportance 3/5
  Why is one unit of money or cryptocurrency fungible, and why is an NFT not? Understand what "fungible" means.
• NFTs: Meaning, Creation and UsesImportance 4/5UPSC 2022
  What does an NFT represent: the asset itself, or ownership of it? Understand where NFTs are created (for example Ethereum), what identification code and metadata each carries, and the kinds of items they can stand for. Does "unique" mean an NFT cannot be traded at all? Why did NFTs become popular in 2021?
• Cryptocurrencies and NFTs ComparedImportance 3/5UPSC 2022
  Compare cryptocurrencies and NFTs on fungibility, purpose, how value arises and where each is traded. Remember CryptoPunks and Bored Ape Yacht Club as examples.

5.Central Bank Digital Currency

• CBDC: Meaning, Retail and Wholesale FormsImportance 3/5
  What is a Central Bank Digital Currency (CBDC)? Who issues the digital rupee (e₹), is it legal tender, and does a wallet earn interest? Understand the retail and wholesale forms and who uses each. Must a CBDC be built on blockchain, or can it use other technologies?
• CBDC and Cryptocurrency ComparedImportance 3/5
  How does a CBDC differ from a cryptocurrency in issuer, control, how its value is set, legal status and technology?
• Programmability and Offline Use of the Digital RupeeImportance 3/5
  What does "programmable" mean for the digital rupee (for example a set purpose, expiry or location limit), and how is it being tried out in benefit transfers? What is offline e₹ meant to do, and can the public already use it fully?
• CBDC and e-RUPI ComparedImportance 3/5
  What kind of instrument is each, money or a voucher, and for what use? Compare issuer, scope, technology and who can use each. Does the RBI describe the digital rupee as a replacement for cash, or as an addition to it?

6.Evolution of the Web

• Web 1.0 and Web 2.0Importance 2/5
  Why is Web 1.0 called the "read-only web"? How did Web 2.0 change the kind of content and the way users take part? Remember the rough period of each.
• Web 3.0Importance 4/5UPSC 2022
  What is Web 3.0 meant to give users over their data and privacy? Understand the roles of decentralisation, blockchain and tokens in it. Is it fully built yet? Are voice assistants such as Siri and Alexa examples of this decentralised idea, or of a different meaning of "Web 3.0"?
• Web 4.0 (Symbiotic Web)Importance 1/5
  Why is Web 4.0 called the symbiotic web? Understand the idea behind the name. Is it a working system yet, or only a forecast?
• Web 5.0Importance 3/5
  Why is Web 5.0 called the "emotional web", and what does it expect the web to do? Is "Web5", proposed in 2022 by TBD, a unit of Jack Dorsey's company Block, the same idea? Understand decentralised identifiers and personal data stores.

7.Extended Reality

• Extended Reality as an Umbrella TermImportance 3/5
  What does Extended Reality (XR) cover? Remember its three types and how they relate to each other.
• Augmented RealityImportance 4/5UPSC 2019
  What is Augmented Reality (AR)? Understand what the user sees and experiences, and remember Pokémon Go as an example. How does AR differ from VR in its effect on the real surroundings?
• Virtual RealityImportance 4/5UPSC 2019
  What is Virtual Reality (VR)? Understand what happens to the user's view of the real world, and remember VR gaming headsets as an example.
• Mixed RealityImportance 3/5
  What is Mixed Reality (MR)? Understand how it differs from AR, and why users can interact with both physical and digital objects. Remember Microsoft HoloLens as an example.
• Holograms and HolographyImportance 3/5
  What is a hologram? Understand the basic principle of holography: how laser light is recorded and then used to rebuild a three-dimensional image. Are the "holograms" of mixed-reality headsets true holograms in this sense, or images shown on a display? Where else are holograms used (security features, entertainment)?
• India's AVGC-XR Ecosystem and the Indian Institute of Creative TechnologyImportance 2/5
  What does AVGC-XR stand for? Remember the Indian Institute of Creative Technology (IICT) in Mumbai and its status as a National Centre of Excellence. What was WAVES 2025, and when and where was it held?

8.Metaverse

• Metaverse: Meaning and Origin of the TermImportance 4/5UPSC 2024
  What is the metaverse? Which novel, which author and which year gave us the term? Understand the idea of a shared online space where people interact with each other and with virtual objects.
• Building Blocks of the MetaverseImportance 3/5
  Which technologies does the metaverse combine? Remember its key elements and the companies investing in it, such as Meta, Microsoft and Roblox. How do blockchain, NFTs and cryptocurrency connect to ownership in virtual worlds?
• Avatars in Virtual WorldsImportance 3/5
  What is an avatar, and what role does it play in the metaverse? Understand the issues of identity, ownership and misuse, including AI-generated avatars.
• Uses and Concerns of the MetaverseImportance 2/5
  Understand the uses of the metaverse (education, health, work, tourism) and the concerns it raises (privacy, addiction, harassment, data, interoperability). How does it mix the physical world and the digital world?

9.3D Printing

• 3D Printing as Additive ManufacturingImportance 3/5
  Why is 3D printing also called additive manufacturing? Understand layer-by-layer building from a digital Computer-Aided Design (CAD) file, the materials used, and how this differs from subtractive manufacturing.
• 3D Printing Techniques (FDM, SLA, SLS)Importance 2/5
  Remember what FDM, SLA and SLS stand for. What material and method does each use to build an object?
• Applications of 3D PrintingImportance 4/5UPSC 2018
  In which fields is 3D printing used? Remember examples such as custom prosthetics, organ models, lightweight aerospace parts, rapid prototyping, buildings and art. Think about whether items such as food or electronics can also be printed.
• Bioprinting and 4D PrintingImportance 3/5UPSC 2018
  Understand bioprinting and what it prints with. What is 4D printing, and what is the "fourth dimension"?
• National Strategy on Additive ManufacturingImportance 2/5
  Which ministry released the National Strategy on Additive Manufacturing, and when? What targets did it set, and for which year? Has the ministry released a new version, called NSAM 2.0?
• India's 3D Printing MilestonesImportance 3/5
  Remember named Indian firsts: the 3D-printed post office and 3D-printed rocket engines. Where was the housing pilot using 3D concrete printing launched in October 2026? What does 3D concrete printing promise for rural housing (time, cost, labour)?

10.Digital Twins and Cyber-Physical Systems

• Digital Twins: Meaning and UsesImportance 3/5
  What is a digital twin? Understand how live sensor data keeps the virtual copy up to date, and how this differs from an ordinary simulation or 3D model. Where is it used (cities, ports, factories, power grids, health)?
• Digital Twins in IndiaImportance 2/5
  What is the Department of Telecommunications' "Sangam: Digital Twin" initiative? Has any major Indian port set up a digital twin, and which one was the first?
• Cyber-Physical SystemsImportance 3/5
  Be clear about what Cyber-Physical Systems (CPS) are and what they bring together. Remember examples (autonomous vehicles, smart factories, smart buildings) and applications in healthcare, agriculture, mining and industry. How do CPS differ from the Internet of Things?
• National Mission on Interdisciplinary Cyber-Physical SystemsImportance 3/5
  Which department runs the National Mission on Interdisciplinary Cyber-Physical Systems (NM-ICPS), and in which year was it approved, with what outlay? Remember the 25 Technology Innovation Hubs, the 4 Technology Translation Research Parks and where they are, and what BharatGen is. For how many years was the mission first approved, and until which year has it been extended?

11.Technology in Transportation

• MaglevImportance 3/5
  How do electromagnetic forces lift and move a maglev train? Understand why floating above the track cuts friction, and what that allows for speed and wear on parts.
• HyperloopImportance 3/5
  How does a hyperloop work with pods in low-pressure tubes? Understand how the near-vacuum and magnetic levitation each cut resistance. Where is India's hyperloop test track, and who supports it?
• National Rail Plan 2030Importance 2/5
  Learn what the National Rail Plan aims to achieve by 2030. Remember its idea of building capacity ahead of demand up to 2050, and what share of freight traffic it targets for the railways.
• Alternative Powertrain Vehicles (BEV, FCEV and FCE-HV)Importance 4/5UPSC 2025
  Which vehicles count as alternative powertrain vehicles? Understand how a Battery Electric Vehicle (BEV), a Fuel Cell Electric Vehicle (FCEV) and a Fuel Cell Electric Hybrid Vehicle (FCE-HV) each store or produce power, and what each releases. What is regenerative braking?
• India's First Hydrogen TrainImportance 3/5
  On which route does India's first hydrogen train run, and when was it flagged off? Which type of fuel cell does it use, and what does it release? Understand how the train is made up and how it is refuelled. What power does each driving power car give, and what is the train's total power?
• Electric Mobility Schemes (NEMMP, FAME and PM E-DRIVE)Importance 3/5
  What were the National Electric Mobility Mission Plan (NEMMP) 2020 and the FAME scheme meant to do? Which scheme finally took over from FAME, and what does PM E-DRIVE support? Until when has PM E-DRIVE been extended, and for which vehicle types?
• Autonomous VehiclesImportance 2/5
  How do autonomous vehicles use sensors, cameras and artificial intelligence to navigate? What does LiDAR use to map surroundings, and what does radar use: light, sound or radio waves?
• Connected Vehicles and Smart Traffic ManagementImportance 2/5
  Be clear about vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication. Understand how real-time sensor and GPS data help manage traffic.
• Drones for Transport and DeliveryImportance 2/5
  How are drones used to carry goods, and what principles keep them stable in flight? Which rules govern civil drones, such as the Drone Rules, 2021? Has the draft Civil Drone (Promotion and Regulation) Bill, 2025 become law?
• eVTOL Aircraft and Advanced Air MobilityImportance 3/5UPSC 2016
  What is an eVTOL aircraft, and how does it take off and fly? Understand its advantages and its challenges. What guidance has the DGCA issued on certifying such aircraft? Has the IIT Madras-incubated startup ePlane shown India's first eVTOL prototype, and when does it plan services?

1. 1.

   Consider the following statements about the features of blockchain:
   1. No central authority controls the network, which makes it resistant to censorship and manipulation.
   2. A transaction recorded in a block can later be reversed by the node that created the block.
   3. Cryptographic techniques are used to secure the data and prevent tampering.
   4. Where blocks are added by solving complex calculations, the process needs high computational capacity and so consumes much energy.
   How many of the above statements are correct?

   1. AOnly one
   2. BOnly two
   3. COnly three
   4. DAll four
2. 2.

   With reference to blockchain technology, consider the following statements:
   1. Its structure confines it to recording cryptocurrency transactions, so it has no use in sectors such as healthcare or supply chains.
   2. Third-party providers can offer cloud-based blockchain solutions to simplify the development of blockchain applications.
   Which of the statements given above is/are correct?

   1. A1 only
   2. B2 only
   3. CBoth 1 and 2
   4. DNeither 1 nor 2
3. 3.

   Consider the following pairs:

   Consensus mechanism	Example of a network using it
   1. Proof of Work	Bitcoin
   2. Proof of Stake	Solana
   3. Delegated Proof of Stake	Ethereum (after the Merge)

   Which of the pairs given above is/are correctly matched?

   1. A2 and 3 only
   2. B1 and 3 only
   3. C1, 2 and 3
   4. D1 and 2 only
4. 4.

   Consider the following pairs:

   Technology	Example
   1. Augmented Reality	Pokémon Go
   2. Virtual Reality	Microsoft HoloLens
   3. Mixed Reality	VR gaming headsets

   How many of the pairs given above are correctly matched?

   1. AOnly one
   2. BOnly two
   3. CAll three
   4. DNone
5. 5.

   Match List I with List II:

   List I (Technology)	List II (Feature)
   A. Full Battery Electric Vehicle	1. Integrates hydrogen fuel cells with rechargeable batteries and uses regenerative braking
   B. Hydrogen Fuel Cell Vehicle	2. Runs solely on rechargeable battery packs, with no ICE, fuel tank or exhaust
   C. Fuel Cell Electric Hybrid Vehicle	3. Generates electricity from a hydrogen-oxygen reaction in a fuel cell stack and emits water vapour and heat
   D. Hyperloop	4. Pods run in low-pressure tubes using magnetic levitation

   Select the correct answer using the code given below:

   1. AA-1, B-2, C-3, D-4
   2. BA-2, B-1, C-3, D-4
   3. CA-2, B-3, C-4, D-1
   4. DA-2, B-3, C-1, D-4
6. 6.

   As of October 2026, consider the following statements:
   Statement-I: A Central Bank Digital Currency (CBDC) is not a cryptocurrency.
   Statement-II: A CBDC is the digital form of a country's sovereign currency, issued by the central bank and at par with physical cash, whereas a cryptocurrency's value is derived from market demand and supply.
   Which one of the following is correct in respect of the above statements?

   1. ABoth Statement-I and Statement-II are correct and Statement-II explains Statement-I
   2. BBoth Statement-I and Statement-II are correct and Statement-II does not explain Statement-I
   3. CStatement-I is correct but Statement-II is incorrect
   4. DStatement-I is incorrect but Statement-II is correct
7. 7.

   The term "metaverse", describing a shared online space where people use virtual avatars to interact with each other and with virtual objects, is inspired by a 1992 novel by which one of the following authors?

   1. AWilliam Gibson
   2. BNeal Stephenson
   3. CErnest Cline
   4. DAldous Huxley
8. 8.

   With reference to Extended Reality technologies, consider the following statements:
   1. Augmented Reality overlays digital information such as images, videos or 3D models onto the real world.
   2. In Virtual Reality, the user continues to see the real surroundings with digital objects added to them.
   3. Mixed Reality blends the real and virtual worlds and lets users interact with both physical and digital objects.
   Which of the statements given above is/are correct?

   1. A1 and 2 only
   2. B2 and 3 only
   3. C1 and 3 only
   4. D1, 2 and 3
9. 9.

   With reference to Non-Fungible Tokens (NFTs), consider the following statements:
   1. Each NFT is assigned a unique identification code and metadata.
   2. NFTs can represent only digital items such as digital art, and never real-world items such as real estate.
   3. NFTs can be traded or exchanged for other NFTs, cryptocurrencies or fiat currency.
   4. NFTs gained significant popularity in 2021 as artists recognised their potential for monetising their work.
   How many of the above statements are correct?

   1. AOnly one
   2. BOnly two
   3. COnly three
   4. DAll four
10. 10.

    With reference to the evolution of the World Wide Web, consider the following statements:
    1. Web 1.0 is often referred to as the "read-only web".
    2. Web 3.0 is the idea of a new internet that gives users more control over their data and privacy, using decentralisation, blockchain and tokenomics.
    3. Web 2.0 marked a shift from dynamic and interactive content back to static web pages.
    Which of the statements given above is/are correct?

    1. A1 and 3 only
    2. B2 and 3 only
    3. C1, 2 and 3
    4. D1 and 2 only
11. 11.

    In Internet and Mobile Association of India v. Reserve Bank of India, the Supreme Court set aside an RBI circular that prohibited the regulated financial sector from dealing in virtual currencies. Which one of the following correctly gives the year of that RBI circular and the year of the Supreme Court's judgment?

    1. ACircular: 2018; judgment: 2020
    2. BCircular: 2018; judgment: 2018
    3. CCircular: 2020; judgment: 2018
    4. DCircular: 2019; judgment: 2020
12. 12.

    As of October 2026, consider the following statements about the digital rupee (e₹) in India:
    1. It is issued by the Reserve Bank of India and is legal tender.
    2. Balances held in e₹ wallets earn interest.
    3. The wholesale form is meant for retail purchases by the general public.
    4. A Central Bank Digital Currency can be built only on blockchain technology.
    How many of the above statements are correct?

    1. AOnly one
    2. BOnly two
    3. COnly three
    4. DAll four
13. 13.

    With reference to the metaverse, consider the following statements:
    1. Virtual Reality, which gives immersive experiences that replace the real world, is a key element of the metaverse.
    2. The metaverse aims to keep the physical and digital worlds clearly separate from each other.
    3. Online games and social media are among the key elements of the metaverse.
    Which of the statements given above is/are correct?

    1. A1 and 2 only
    2. B1 and 3 only
    3. C2 and 3 only
    4. D1, 2 and 3
14. 14.

    With reference to 3D printing, consider the following statements:
    1. Custom prosthetics and organ models are among its applications in medicine.
    2. In aerospace, it is used mainly for heavy components rather than lightweight ones.
    3. The materials it can deposit are restricted to plastics.
    4. A digital Computer-Aided Design (CAD) file is translated into machine instructions that control the printer's movement and material deposition.
    How many of the above statements are correct?

    1. AOnly one
    2. BOnly two
    3. COnly three
    4. DAll four
15. 15.

    Ethereum changed its consensus mechanism in an event known as the Merge. Which one of the following correctly states the mechanism it used before and after the Merge?

    1. AProof of Stake before; Proof of Work after
    2. BProof of Work before; Delegated Proof of Stake after
    3. CProof of Work before; Proof of Stake after
    4. DProof of Stake before; Delegated Proof of Stake after

1. 1.

   UPSC 2026

   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 :

   1. A1 and 3
   2. B2 and 4 only
   3. C1, 2 and 4
   4. D1 and 4 only
2. 2.

   UPSC 2025

   Consider the following types of vehicles :
   I. Full battery electric vehicles
   II. Hydrogen fuel cell vehicles
   III. Fuel cell-electric hybrid vehicles
   How many of the above are considered as alternative powertrain vehicles?

   1. AOnly one
   2. BOnly two
   3. CAll the three
   4. DNone
3. 3.

   UPSC 2024

   Which one of the following words/phrases is most appropriately used to denote “an interoperable network of 3D virtual worlds that can be accessed simultaneously by millions of users, who can exert property rights over virtual items” ?

   1. ABig data analytics
   2. BCryptography
   3. CMetaverse
   4. DVirtual matrix
4. 4.

   UPSC 2022

   With reference to Web 3·0, consider the following statements :
   1. Web 3·0 technology enables people to control their own data.
   2. In Web 3·0 world, there can be blockchain based social networks.
   3. Web 3·0 is operated by users collectively rather than a corporation.
   Which of the statements given above are correct ?

   1. A1 and 2 only
   2. B2 and 3 only
   3. C1 and 3 only
   4. D1, 2 and 3
5. 5.

   UPSC 2022

   With reference to Non-Fungible Tokens (NFTs), consider the following statements :
   1. They enable the digital representation of physical assets.
   2. They are unique cryptographic tokens that exist on a blockchain.
   3. They can be traded or exchanged at equivalency and therefore can be used as a medium of commercial transactions.
   Which of the statements given above are correct ?

   1. A1 and 2 only
   2. B2 and 3 only
   3. C1 and 3 only
   4. D1, 2 and 3
6. 6.

   UPSC 2020

   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 are about cryptocurrency 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 ?

   1. A1 only
   2. B1 and 2 only
   3. C2 only
   4. D1 and 3 only
7. 7.

   UPSC 2019

   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?

   1. A1 and 2 only
   2. B3 and 4
   3. C1, 2 and 3
   4. D4 only
8. 8.

   UPSC 2018

   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 ?

   1. A1 and 3 only
   2. B2 only
   3. C2 and 3 only
   4. D1, 2 and 3
9. 9.

   UPSC 2018

   "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 :

   1. A1, 3 and 4 only
   2. B2, 3 and 5 only
   3. C1 and 4 only
   4. D1, 2, 3, 4 and 5
10. 10.

    UPSC 2016

    What is 'Greased Lightning–10 (GL–10)', recently in the news?

    1. AElectric plane tested by NASA
    2. BSolar-powered two-seater aircraft designed by Japan
    3. CSpace observatory launched by China
    4. DReusable rocket designed by ISRO
11. 11.

    UPSC 2016

    With reference to 'Bitcoins', sometimes seen in the news, which of the following statements is/are correct?
    1. Bitcoins are tracked by the Central Banks of the countries.
    2. Anyone with a Bitcoin address can send and receive Bitcoins from anyone else with a Bitcoin address.
    3. Online payments can be sent without either side knowing the identity of the other.
    Select the correct answer using the code given below.

    1. A1 and 2 only
    2. B2 and 3 only
    3. C3 only
    4. D1, 2 and 3