Computing, Internet and Communication Technology

1.Electromagnetic Waves and the Spectrum

• Nature and Properties of Electromagnetic WavesImportance 4/5UPSC 2002, 2008
  Understand what an electromagnetic wave is made of and why it is called transverse. Why does it need no medium, unlike a mechanical wave? How are wavelength, frequency and energy related? Remember the wave behaviours it shows (reflection, refraction, diffraction, polarisation) and the photon idea.
• Order of the Electromagnetic SpectrumImportance 4/5UPSC 2008, 2009
  Remember the seven bands in order, from radio waves to gamma rays, with a rough sense of their wavelengths. Along this order, which way do frequency, wavelength and energy change? At about which wavelength, and in which band, is the Sun's radiation most intense?
• Atmospheric Penetration and Uses of Each BandImportance 4/5UPSC 2009, 2010
  For each band, does it reach the ground through the atmosphere, or is it absorbed (and by what)? Remember the main uses of each band. Why can radio and visible-light telescopes work from the ground, while X-ray astronomy needs to go to space?
• Radio Frequency Bands and Spectrum Assignment in IndiaImportance 3/5
  How are radio frequencies grouped into named bands (VHF, UHF, SHF, EHF)? Know which bands mobile services, Wi-Fi and satellites use. Understand spectrum as a scarce public resource, and how the Telecommunications Act, 2023 provides for auction and for administrative assignment. Why is this choice contested for satellite services?

2.Computer Networks

• Network Types by Coverage (PAN, LAN, MAN, WAN)Importance 4/5
  Remember the four network types by the area they cover, with an example of each. What is the approximate range of a PAN? How do a MAN and a WAN differ? Which type joins LANs and MANs over long distances?
• Virtual Private Network (VPN)Importance 4/5UPSC 2011
  How does a VPN keep data safe on the public internet? Understand encryption, tunnelling and the hiding of the user's IP address. Why do companies and ordinary users each use VPNs? What have Indian rules asked VPN providers to keep about their users?

3.Wireless Communication Technologies

• Wi-Fi, Wi-Fi Direct and HotspotsImportance 4/5UPSC 2010, 2011
  What is Wi-Fi, and what does a router or access point do in it? Distinguish Wi-Fi Direct from a hotspot. Remember the radio bands Wi-Fi uses.
• BluetoothImportance 4/5UPSC 2010, 2011
  Learn what Bluetooth is used for. How does it differ from Wi-Fi in range, speed and purpose?
• Zigbee and DECT Cordless PhonesImportance 2/5
  Remember what each protocol is for. Why does Zigbee suit home automation and sensor networks? Which household device uses DECT, and what does it link?
• WiMAXImportance 3/5UPSC 2009
  What does WiMAX stand for, and what kind of network was it designed for? How does its coverage differ from that of Wi-Fi?
• Short-Range Devices Compared (Range and Penetration)Importance 4/5UPSC 2010, 2022
  How do Bluetooth, Wi-Fi, DECT and Li-Fi compare in range and in passing through walls? Which links pass through thin walls, and which are stopped by opaque objects? What obstacles weaken Bluetooth? Understand what "short-range device" means, and whether RFID, WLAN and CCTV count as such devices.
• PM-WANI Public Wi-Fi FrameworkImportance 3/5
  What is PM-WANI, and what makes it a licence-free model? Know its four actors (PDO, PDOA, App Provider, Central Registry) and when the Cabinet approved it. Why did uptake lag at first, and how has TRAI responded on backhaul tariffs? How many PM-WANI hotspots exist now, and what drives that number?
• Delicensing of the Lower 6 GHz Band for Wi-FiImportance 3/5
  Which frequencies of the 6 GHz band has the Department of Telecommunications opened for licence-free Wi-Fi? Understand the rules for low-power indoor and very-low-power devices, and whether such use is protected from interference. Why was the upper 6 GHz band kept back, and for which service?
• Li-Fi and Visible Light CommunicationImportance 5/5UPSC 2016, 2020
  How does Li-Fi carry data on light, and how is it related to visible light communication? Remember the wavelength range visible light communication uses. What are its advantages over Wi-Fi and Bluetooth, and what limits it? Is Li-Fi free of all interference, or only of radio interference?
• Infrared CommunicationImportance 2/5
  How is infrared light used to send data over short distances (for example in remote controls)? Why does it need a clear line of sight, unlike radio links?
• Near Field Communication (NFC)Importance 4/5UPSC 2015
  How does NFC move data between two devices held close together? Remember its range and its uses, such as contactless payments, file sharing and access control. How do NFC, RFID and Bluetooth differ in range and use?
• Radio-Frequency Identification (RFID) and FASTagImportance 5/5UPSC 2022
  Know the two parts of an RFID system and what each does. What kinds of data can a tag hold? Remember its uses in logistics, inventory and access control, and FASTag as the Indian example. How do passive and active tags differ?
• Tokenisation in Contactless PaymentsImportance 2/5
  What is a payment token, and why does using it instead of the real card number protect the customer? What did the RBI's card tokenisation rules, which took effect in October 2022, change for stored card details?

4.Barcodes and QR Codes

• Barcodes (1D and 2D)Importance 3/5UPSC 2006
  How does a barcode store data so that a machine can read it? Understand how one-dimensional and two-dimensional barcodes differ.
• QR Codes and Their Capacity Compared with BarcodesImportance 3/5
  Know what QR stands for and where QR codes are widely used. Remember how the storage capacity of a QR code compares with that of a barcode, with the approximate figures for each.

5.Cellular Wireless Communication Technologies

• Cellular Networks and the Generations from 1G to 4GImportance 4/5UPSC 2010
  Understand how mobile phones use ground-based cells to carry voice and data. Remember what each generation from 1G to 4G added, with its typical frequency bands and latency. What is latency, and why does it matter for video calls and gaming?
• 5G: Features, Spectrum Bands and LatencyImportance 5/5
  How does 5G differ from 4G in speed, latency and range of uses, including IoT? Distinguish sub-6 GHz bands from millimetre-wave bands (coverage against capacity). When did 5G services start in India, and which were the main 5G bands in the 2022 auction?
• Standalone and Non-Standalone 5GImportance 3/5
  How do standalone and non-standalone 5G differ in the core network they use? Which gives the full set of 5G features, and which is cheaper and quicker to roll out? Why does this choice matter to operators?
• 6G and India's 6G Programme (Bharat 6G Vision, Bharat 6G Alliance)Importance 4/5
  What does 6G promise in frequency range, speed, delay and AI integration? Know India's Bharat 6G Vision and its 2030 goal, what the Bharat 6G Alliance is, and why a 6G spectrum roadmap is needed. What is ITU's IMT-2030, and which usage scenario did India propose for its framework?
• LTE and VoLTEImportance 4/5UPSC 2019
  How is LTE different from VoLTE? Remember LTE's speed, latency and all-IP design. Understand what VoLTE does for calls: voice quality, use of data during a call, and call set-up time.
• Voice Over Internet Protocol (VoIP)Importance 3/5
  How does VoIP turn speech into data packets, and what is a packet-switched network? How does this differ from a circuit-switched call? Remember the advantages of VoIP.
• VoWiFi (Wi-Fi Calling)Importance 3/5
  When is Wi-Fi calling most useful? How does it differ from a call made through a messaging app, and from VoLTE? Understand how a call can pass between Wi-Fi and LTE without breaking.
• Telecom Infrastructure Sharing (Active, Passive and Hybrid)Importance 2/5
  What do mobile operators share (base stations, towers, backhaul, spectrum), and why? Which parts of a network count as passive infrastructure and which as active? What is hybrid sharing? Understand the benefits: lower cost, faster 5G rollout and fewer towers.
• Network SlicingImportance 3/5
  How can several virtual networks run on one physical network, each tailored to a group of users? Which kind of 5G network supports slicing?
• Open Radio Access Network (O-RAN)Importance 3/5
  What does "open" mean in Open RAN? Understand how separating hardware from software lets operators mix equipment from different vendors. Why does this matter for India's own telecom equipment?
• e-SIMImportance 3/5
  What is an e-SIM, and how is an operator's profile loaded onto it remotely? Distinguish SIM, e-SIM and iSIM. Where is it used (phones, wearables, connected devices)? What are its advantages and concerns compared with a physical SIM?
• TRAI's Consumer Tools: MyCall App and Digital Connectivity Rating of PropertiesImportance 2/5
  Learn what the TRAI MyCall app collects from users and who receives it. What does the Digital Connectivity Rating of a property measure (fibre, mobile, in-building coverage, Wi-Fi), and under which regulations? Is the property rating voluntary or compulsory?

6.Internet of Things

• Internet of Things and Machine-to-Machine CommunicationImportance 5/5
  Be clear about what the Internet of Things is. Understand how sensors, software and connectivity let a device collect data and act on it, and why each device needs a unique identifier. What does machine-to-machine communication mean?
• Applications of IoTImportance 4/5UPSC 2018, 2019
  Remember how IoT is used in smart infrastructure (power grids, transport, safety and surveillance), in remote healthcare and agriculture, and in homes and cities.
• Role of 5G and Edge Computing in IoTImportance 3/5
  How do 5G and edge computing each help IoT? Understand what 5G adds (speed and capacity) and what edge processing adds (low delay, reliability and security). Which new uses, such as autonomous vehicles, do they make possible?

7.Optical Fibre and Internet Infrastructure

• Total Internal Reflection and the Structure of an Optical FibreImportance 4/5
  What is total internal reflection, and what two conditions are needed for it? Understand how the core and cladding of a fibre keep light inside it. Which of the two has the higher refractive index?
• Advantages of Optical Fibre Over Copper WiresImportance 3/5
  Why is optical fibre better than copper wire for carrying data? Be clear about signal loss (attenuation), bandwidth, interference and weight.
• Undersea Cables and Cable Landing StationsImportance 4/5
  What share of international data travels on undersea cables? What is a cable landing station, and in which cities are most of India's landings concentrated? Why are cable cuts, such as those in the Red Sea in 2025, a risk? Understand the safeguards proposed: critical-infrastructure status and India-flagged repair ships.
• New Undersea Cables Landing in India (I-2SEA, America-India Connect)Importance 3/5
  Which countries does the I-2SEA cable connect, where does it land in India, and what kind of traffic is it built for? Has it entered service yet, and if not, when is it planned to start? What is Google's America-India Connect, and what gateway does it plan at Visakhapatnam?
• BharatNet and Digital Bharat NidhiImportance 2/5
  What does BharatNet connect? What changed in the Amended BharatNet Program of 2023: the role of BSNL, the network design, operation and maintenance, and the option for states to implement it? Understand how Digital Bharat Nidhi relates to the earlier Universal Service Obligation Fund and to the Telecommunications Act, 2023.

8.Satellite and White-Space Internet

• Satellite Internet: GEO, MEO and LEO ConstellationsImportance 4/5
  How does satellite internet reach a user (user terminal, satellite, ground gateway)? How do geostationary, medium-earth-orbit and low-earth-orbit systems differ in altitude, delay and number of satellites? Remember the main constellations (Starlink, Eutelsat OneWeb, Amazon's, Jio-SES) and the orbit each uses. Where does satellite internet help most?
• Licensing and Spectrum for Satellite Internet in IndiaImportance 4/5
  Which two permissions does a satellite internet operator need in India, and from which bodies? How is its spectrum to be assigned under the 2023 Act, and what did TRAI recommend in May 2025 on charges and term? Has the Union Cabinet decided on satellite spectrum pricing, and has commercial service begun in India?
• Direct-to-Device Satellite ConnectivityImportance 2/5
  Be clear about what direct-to-device satellite connectivity means. Understand how it differs from satellite internet that needs a dish or terminal. What can an ordinary phone do through it?
• TV White Space InternetImportance 2/5
  Learn what TV white space is. Why do such frequencies suit rural broadband (long range, passing obstacles)? Has India delicensed them?

9.Big Data and Computing

• Big Data and Its CharacteristicsImportance 4/5
  What makes data "big"? Remember the three kinds of data (structured, semi-structured, unstructured) and the Vs of big data (volume, velocity, variety, veracity, value). What challenges arise in collecting, storing and analysing it, and how is it used in governance?
• Data Engineering and Data ScienceImportance 2/5
  Be clear about the work of a data engineer and of a data scientist. Understand ETL and why the two roles depend on each other.
• Cloud Computing and How It WorksImportance 4/5
  Be clear about what cloud computing is and how it differs from using a local server. Understand its features: resource pooling, on-demand pay-as-you-go use, virtualisation, automated management and access from any device.
• Cloud Service Models (IaaS, PaaS and SaaS)Importance 5/5UPSC 2022
  How do IaaS, PaaS and SaaS differ in what the provider supplies and what the client manages? Remember well-known examples of each. Which model suits a firm that wants to rent servers, and which a user who only wants to use an email service?
• Cloud Deployment Models (Public, Private, Hybrid and Community)Importance 3/5
  How do public, private, hybrid and community clouds differ in who owns and uses them? When would an organisation choose each? How are deployment models different from service models?
• MeghRaj (GI Cloud)Importance 3/5
  What is MeghRaj, and why did the Government of India build it? Understand how separate cloud environments follow common protocols and standards. Remember the ministry that launched it and the year.
• Edge Computing: Architecture, Features and ApplicationsImportance 4/5
  What is edge computing, and how does it cut delay? Understand the device, edge and cloud layers and the work of each. Remember its features and its uses in IoT, autonomous vehicles, virtual reality and augmented reality.
• Cloud and Edge Computing ComparedImportance 4/5
  How do cloud and edge computing compare in data processing, need for internet, cost, storage and use cases? Why do the two work together rather than replace each other?
• Data Centres and Their Power, Water and Cooling NeedsImportance 3/5
  What does a data centre contain, and what does "hyperscale" mean? Why do power, water and cooling decide where data centres are built? Why do AI workloads add to energy and water stress?
• India's Data Centre Push (Gujarat Policy, Budget Incentives, AI Hubs)Importance 3/5
  Why is India expanding data-centre capacity, given its share of the world's data compared with its share of capacity? What does Gujarat's Data Centre Policy 2026–29 require on green power and desalination, and what is Dholera's role? What tax benefit for foreign cloud firms came with Union Budget 2026–27? What is Google's AI hub at Visakhapatnam?
• Orbital and Underwater Data CentresImportance 3/5
  Why are data centres in orbit proposed? Understand the engineering problems: cooling by radiation only, launch cost, no repair, radiation and delay. Why did Microsoft's underwater Project Natick not continue? Has any company yet placed a data-centre satellite in orbit?
• Supercomputers and FLOPSImportance 3/5UPSC 1997
  How does a supercomputer gain its speed? What does FLOPS measure, and what do petascale and exascale mean?
• World's Leading Supercomputers and the TOP500 ListImportance 3/5
  What is the TOP500 list, and how often is it published? Which system and which country lead the latest list, and how many exascale systems exist?
• India's Supercomputing History (C-DAC and the PARAM Series)Importance 3/5UPSC 2004
  What led India to build its own supercomputers, and which institution took the lead? Remember the early PARAM systems (8000 and 10000), BARC's Anupam series and ANURAG's PACE series.
• National Supercomputing Mission and India's Major SystemsImportance 4/5
  What is the aim of the National Supercomputing Mission, when did it begin, and which agencies run it? Remember India's major systems and their purposes: AIRAWAT, PARAM Siddhi-AI, PARAM Rudra, Arka and Arunika. How many systems has the Mission installed so far?

1. 1.

   With reference to Li-Fi and Visible Light Communication (VLC), consider the following statements:
   1. Li-Fi is a form of VLC and can provide high-speed, bi-directional communication.
   2. VLC uses electromagnetic spectrum wavelengths from 375 nm to 780 nm.
   3. Li-Fi signals pass easily through opaque walls, unlike Wi-Fi.
   Which of the statements given above is/are correct?

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

   With reference to Radio-Frequency Identification (RFID), consider the following statements:
   1. An RFID system consists of a tag containing a microchip and an antenna, and a reader.
   2. The reader emits radio signals and receives the tag's response.
   3. RFID identifies and tracks objects using infrared light.
   4. RFID tags can store only serial numbers and no other data.
   How many of the statements given above are correct?

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

   Consider the following statements about mobile network technologies:
   1. 5G aims for latencies as low as 1 ms.
   2. 5G uses only millimetre-wave bands above 24 GHz.
   3. LTE (4G) has a latency in the range of 20 to 40 milliseconds.
   Which of the statements given above is/are correct?

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

   Consider the following statements:
   Statement-I: Non-standalone (NSA) 5G allows a faster and more cost-effective rollout than standalone 5G.
   Statement-II: Non-standalone 5G relies on the existing 4G core network for support.
   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
5. 5.

   Consider the following pairs:

   Cloud service model	Example
   1. Infrastructure as a Service (IaaS)	Amazon EC2
   2. Platform as a Service (PaaS)	Microsoft Office 365
   3. Software as a Service (SaaS)	AWS Elastic Beanstalk

   How many of the above pairs are correctly matched?

   1. AOnly one
   2. BOnly two
   3. CAll three
   4. DNone
6. 6.

   With reference to the Internet of Things (IoT), consider the following statements:
   1. IoT devices have unique identifiers.
   2. IoT enables machine-to-machine (M2M) communication without human intervention.
   3. IoT devices, equipped with sensors, software and communication technologies, collect, transmit and act upon data from their environments.
   How many of the statements given above are correct?

   1. AOnly one
   2. BOnly two
   3. CAll three
   4. DNone
7. 7.

   Consider the following statements about the electromagnetic spectrum:
   1. The Sun's maximum intensity lies in visible light, peaking near 500 nanometres.
   2. Along the spectrum from radio waves to gamma rays, frequency decreases while wavelength increases.
   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
8. 8.

   Consider the following statements about electromagnetic radiation and the Earth's atmosphere:
   1. Infrared radiation is partially absorbed by the atmosphere, especially by water vapour and carbon dioxide.
   2. Most ultraviolet radiation passes through the atmosphere without absorption.
   3. X-rays are absorbed by the Earth's atmosphere.
   Which of the statements given above is/are correct?

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

   Match List I with List II:

   List I (Network)	List II (Coverage)
   A. Personal Area Network (PAN)	1. A city or a large campus, connecting multiple buildings
   B. Local Area Network (LAN)	2. A single building, a campus or a group of nearby buildings
   C. Metropolitan Area Network (MAN)	3. Cities, countries or continents, connecting LANs and MANs
   D. Wide Area Network (WAN)	4. Smartphones, tablets and laptops within about 10 metres

   Select the correct answer using the code given below:

   1. AA-4, B-2, C-1, D-3
   2. BA-4, B-1, C-2, D-3
   3. CA-2, B-4, C-3, D-1
   4. DA-4, B-2, C-3, D-1
10. 10.

    In the context of computer networks, which one of the following best describes a Virtual Private Network (VPN)?

    1. AA network of devices that communicate only within a range of about 10 metres
    2. BA technology allowing secure and encrypted communication over an untrusted network such as the internet
    3. CA model in which users access a shared pool of computing resources through a service provider
    4. DA network that covers a city and connects multiple buildings within it
11. 11.

    Consider the following pairs:

    Technology	Description
    1. Wi-Fi Direct	Allows devices to connect to each other directly without a traditional Wi-Fi network
    2. WiMAX	A wireless standard designed for personal area networks
    3. Hotspot	A physical location giving internet access, typically through Wi-Fi over a WLAN whose router is connected to an internet service provider

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

    1. A1 and 2 only
    2. B2 and 3 only
    3. C1 and 3 only
    4. D1, 2 and 3
12. 12.

    With reference to Near Field Communication (NFC), consider the following statements:
    1. It is designed for devices that are typically several metres apart.
    2. It enables data exchange between devices in close proximity, typically within a few centimetres.
    3. It is used for contactless payments, file sharing and access control.
    Which of the statements given above is/are correct?

    1. A1 only
    2. B1 and 2 only
    3. C2 and 3 only
    4. D1, 2 and 3
13. 13.

    Match List I with List II:

    List I (Supercomputer series)	List II (Developer or user)
    A. PARAM	1. BARC
    B. Anupam	2. ANURAG
    C. PACE	3. C-DAC
    D. Mihir	4. NCMRWF, Noida

    Select the correct answer using the code given below:

    1. AA-3, B-1, C-2, D-4
    2. BA-3, B-2, C-1, D-4
    3. CA-1, B-3, C-2, D-4
    4. DA-3, B-1, C-4, D-2
14. 14.

    Consider the following statements about 6G mobile technology:
    1. It is expected to offer data rates over 100 Gbps with AI integration.
    2. It is expected to make use of terahertz bands (roughly 100 GHz to 1 THz), among others.
    3. Its latency is expected to be in the range of 200 to 400 ms.
    How many of the statements given above are correct?

    1. AOnly one
    2. BOnly two
    3. CAll three
    4. DNone
15. 15.

    With reference to LTE (Long Term Evolution) and VoLTE (Voice over LTE), consider the following statements:
    1. LTE has an all-IP architecture that integrates voice, video and data services.
    2. LTE is a data-only technology, while VoLTE is a voice-only technology.
    3. VoLTE allows data to be used during a call without interruption.
    Which of the statements given above is/are correct?

    1. A1 only
    2. B2 only
    3. C1 and 3 only
    4. D2 and 3 only
16. 16.

    Optical fibres carry light signals over long distances on the principle of total internal reflection. Which one of the following is the condition for total internal reflection?

    1. ALight moves from a rarer to a denser medium at an angle of incidence greater than the critical angle
    2. BLight moves from a denser to a rarer medium at an angle of incidence greater than the critical angle
    3. CLight moves from a denser to a rarer medium at an angle of incidence less than the critical angle
    4. DLight moves from a rarer to a denser medium at any angle of incidence
17. 17.

    Consider the following statements:
    Statement-I: Edge computing, like cloud computing, requires reliable internet connectivity to process data.
    Statement-II: Edge computing processes data locally, closer to its source.
    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
18. 18.

    With reference to big data, consider the following statements:
    1. It may consist of structured, semi-structured or unstructured data.
    2. It refers only to the sheer quantity of data and does not involve challenges of collecting, storing and analysing it.
    3. It is so voluminous that traditional data processing methods become inadequate.
    How many of the statements given above are correct?

    1. AOnly one
    2. BOnly two
    3. CAll three
    4. DNone
19. 19.

    Which one of the following is NOT a feature of cloud computing?

    1. AResource pooling that dynamically allocates resources based on user demand
    2. BOn-demand access, often with a pay-as-you-go pricing model
    3. CVirtualisation to create scalable virtual machines and environments
    4. DFixed allocation of dedicated hardware to each user irrespective of demand
20. 20.

    Consider the following statements about satellite internet systems:
    1. Medium-earth-orbit (MEO) satellites have higher latency than geostationary satellites.
    2. Low-earth-orbit (LEO) systems need only a handful of satellites to give global coverage.
    3. Geostationary satellites are well suited to real-time applications.
    How many of the statements given above are correct?

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

1. 1.

   UPSC 2022

   With reference to “Software as a Service (SaaS)”, consider the following statements :
   1. SaaS buyers can customise the user interface and can change data fields.
   2. SaaS users can access their data through their mobile devices.
   3. Outlook, Hotmail and Yahoo! Mail are forms of SaaS.
   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
2. 2.

   UPSC 2022

   Consider the following communication technologies :
   1. Closed-circuit Television
   2. Radio Frequency Identification
   3. Wireless Local Area Network
   Which of the above are considered Short-Range devices/technologies ?

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

   UPSC 2020

   With reference to Visible Light Communication (VLC) technology, which of the following statements are correct ?
   1. VLC uses electromagnetic spectrum wavelengths 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 :

   1. A1, 2 and 3 only
   2. B1, 2 and 4 only
   3. C1, 3 and 4 only
   4. D2, 3 and 4 only
4. 4.

   UPSC 2019

   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.

   1. A1 only
   2. B2 only
   3. CBoth 1 and 2
   4. DNeither 1 nor 2
5. 5.

   UPSC 2019

   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.

   1. A1 only
   2. B2 and 3 only
   3. C3 only
   4. D1, 2 and 3
6. 6.

   UPSC 2018

   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 terms best applies to the above scenario ?

   1. ABorder Gateway Protocol
   2. BInternet of Things
   3. CInternet Protocol
   4. DVirtual Private Network
7. 7.

   UPSC 2016

   With reference to 'LiFi', recently in the news, which of the following statements is/are correct?
   1. It uses light as the medium for high-speed data transmission.
   2. It is a wireless technology and is several times faster than 'WiFi'.
   Select the correct answer using the code given below.

   1. A1 only
   2. B2 only
   3. CBoth 1 and 2
   4. DNeither 1 nor 2
8. 8.

   UPSC 2016

   'Project Loon', sometimes seen in the news, is related to

   1. Awaste management technology
   2. Bwireless communication technology
   3. Csolar power production technology
   4. Dwater conservation technology
9. 9.

   UPSC 2015

   With reference to ‘Near Field Communication (NFC) Technology’, which of the following statements is/are correct?
   1. It is a contactless communication technology that uses electromagnetic radio fields.
   2. NFC is designed for use by devices which can be at a distance of even a metre from each other.
   3. NFC can use encryption when sending sensitive information.
   Select the correct answer using the code given below.

   1. A1 and 2 only
   2. B3 only
   3. C1 and 3 only
   4. D1, 2 and 3
10. 10.

    UPSC 2011

    What is the difference between Bluetooth and Wi-Fi devices ?

    1. ABluetooth uses 2.4 GHz radio frequency band, whereas Wi-Fi can use 2.4 GHz or 5 GHz frequency band
    2. BBluetooth is used for Wireless Local Area Networks (WLAN) only, whereas Wi-Fi is used for Wireless Wide Area Networks (WWAN) only
    3. CWhen information is transmitted between two devices using Bluetooth technology, the devices have to be in the line of sight of each other, but when Wi-Fi technology is used the devices need not be in the line of sight of each other
    4. DThe statements (a) and (b) given above are correct in this context
11. 11.

    UPSC 2011

    A new optical disc format known as the Blu-ray Disc (BD) is becoming popular. In what way is it different from the traditional DVD?
    1. DVD supports Standard Definition video while BD supports High Definition video.
    2. Compared to a DVD, the BD format has several times more storage capacity.
    3. Thickness of BD is 2.4 mm while that of DVD is 1.2 mm.
    Which of the statements given above is/are correct?

    1. A1 only
    2. B1 and 2 only
    3. C2 and 3 only
    4. D1, 2 and 3
12. 12.

    UPSC 2011

    What is "Virtual Private Network"?

    1. AIt is a private computer network of an organization where the remote users can transmit encrypted information through the server of the organization.
    2. BIt is a computer network across a public internet that provides users access to their organization's network while maintaining the security of the information transmitted.
    3. CIt is a computer network in which users can access a shared pool of computing resources through a service provider.
    4. DNone of the statements (a), (b) and (c) given above is a correct description of Virtual Private Network.
13. 13.

    UPSC 2010

    If a potato is placed on a pure paper plate which is white and unprinted and put in a microwave oven, the potato heats up but the paper plate does not. This is because

    1. APotato is mainly made up of starch whereas paper is mainly made up of cellulose
    2. BPotato transmits microwaves whereas paper reflects microwaves
    3. CPotato contains water whereas paper does not contain water
    4. DPotato is a fresh organic material whereas paper is a dead organic material
14. 14.

    UPSC 2010

    Consider the following :
    1. Bluetooth device
    2. Cordless phone
    3. Microwave oven
    4. Wi-Fi device
    Which of the above can operate between 2.4 and 2.5 GHz range of radio-frequency band ?

    1. A1 and 2 only
    2. B3 and 4 only
    3. C1, 2 and 4 only
    4. D1, 2, 3 and 4
15. 15.

    UPSC 2010

    Which among the following do/does not belong/belongs to the GSM family of wireless technologies?

    1. AEDGE
    2. BLTE
    3. CDSL
    4. DBoth EDGE and LTE
16. 16.

    UPSC 2009

    Which one of the following types of waves are used in a night vision apparatus ?

    1. ARadio waves
    2. BMicrowaves
    3. CInfra-red waves
    4. DNone of the above
17. 17.

    UPSC 2009

    Which one among the following has the highest energy ?

    1. ABlue light
    2. BGreen light
    3. CRed light
    4. DYellow light
18. 18.

    UPSC 2009

    WiMAX is related to which one of the following ?

    1. ABiotechnology
    2. BSpace technology
    3. CMissile technology
    4. DCommunication technology
19. 19.

    UPSC 2008

    Assertion (A): In the visible spectrum of light, red light is more energetic than green light. Reason (R): The wavelength of red light is more than that of green light.

    1. ABoth A and R are individually true and R is the correct explanation of A
    2. BBoth A and R are individually true but R is not the correct explanation of A
    3. CA is true but R is false
    4. DA is false but R is true
20. 20.

    UPSC 2008

    Assertion (A): Radio waves bend in a magnetic field. Reason (R): Radio waves are electromagnetic in nature.

    1. ABoth A and R are individually true and R is the correct explanation of A
    2. BBoth A and R are individually true but R is not the correct explanation of A
    3. CA is true but R is false
    4. DA is false but R is true
21. 21.

    UPSC 2007

    Who among the following is considered as the inventor of the World Wide Web (WWW)?

    1. AEdward Kasner
    2. BBill Gates
    3. CTim Berners-Lee
    4. DVinod Bham
22. 22.

    UPSC 2007

    Match List-I with List-II and select the correct answer using the code given below the lists:
    List-I (Company)
    A. Chevron
    B. AT&T
    C. AMD
    D. Enercon GmbH
    List-II (Major Area/Product)
    1. Wind Energy
    2. Oil
    3. Telephone, Internet
    4. Micro-processor
    Codes:

    1. AA-2 B-1 C-4 D-3
    2. BA-4 B-3 C-2 D-1
    3. CA-2 B-3 C-4 D-1
    4. DA-4 B-1 C-2 D-3
23. 23.

    UPSC 2006

    What is the Universal Product Code (UPC) adopted for?

    1. AFire safety code in buildings
    2. BEarthquake-resistant buildings code
    3. CBar code
    4. DAgainst adulteration eatables
24. 24.

    UPSC 2005

    Consider the following statements :
    1. A geostationary satellite is at an approximate height of 10,000 km
    2. FM transmission of music is of very good quality because the atmospheric or man-made noises which are generally frequency variations can do little harm.
    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
25. 25.

    UPSC 2004

    Param Padam, which was in news recently, is

    1. AA new Civilian Award instituted by the Government of India
    2. BThe name of a supercomputer developed by India
    3. CThe name given to a proposed network of canals
    4. DA software programme to facilitate e-governance in Madhya Pradesh
26. 26.

    UPSC 2004

    Consider the following statements:
    1. Smart Card is a plastic card with an embedded microchip.
    2. Digital Technology is primarily used with new physical communication medium such as satellite and fibre optics transmission.
    3. A digital library is a collection of documents in an organized electronic form available on the Internet only.
    Which of these statements given above is/are correct?

    1. A3 only
    2. B1 and 2
    3. C2 and 3
    4. D1, 2 and 3
27. 27.

    UPSC 2000

    The memory of a computer is commonly expressed in terms of Kilobytes or Megabytes. A byte is made up of

    1. Aeight binary digits
    2. Beight decimal digits
    3. Ctwo binary digits
    4. Dtwo decimal digits
28. 28.

    UPSC 1999

    Assertion (A): Information technology is fast becoming a very important field of activity in India. Reason (R): Software is one of the major exports of the country and India has a very strong base in hardware.

    1. ABoth A and R are true, and R is the correct explanation of A
    2. BBoth A and R are true, but R is not a correct explanation of A
    3. CA is true, but R is false
    4. DA is false, but R is true
29. 29.

    UPSC 1997

    The world’s fastest computer has been able to perform (as of Dec. 1996)

    1. A106 operations per second
    2. B109 operations per second
    3. C1012 operations per second
    4. D1015 operations per second
30. 30.

    UPSC 1995

    The technique used to transmit audio signals in television broadcasts is

    1. AAmplitude Modulation
    2. BFrequency Modulation
    3. CPulse Code Modulation
    4. DTime Division Multiplexing
31. 31.

    UPSC 2002

    Consider the following statements:
    1. Light of longer wavelength is scattered much more than light of shorter wavelength.
    2. The speed of visible light in water is 0.95 times its speed in vacuum.
    3. Radio waves are produced by rapidly oscillating electrical currents.
    4. To detect over-speeding vehicles, police use the Doppler effect of reflected short radio waves.
    Which of these statements are correct?

    1. A1 and 2
    2. B1 and 3
    3. C2 and 4
    4. D3 and 4