WBCS Main Computer & Technology Questions and Answers (Previous Year Paper)

Answer: (D) Ministry of Communication

Explanation: C-DOT (Centre for Development of Telematics) was set up in August 1984 as an autonomous telecom R&D centre. It works under the Department of Telecommunications, Ministry of Communications, and was founded to develop indigenous digital switching technology.

Telecom and IT Institutions:

Answer: (A) Pune

Explanation: The National Institute of Virology (NIV) is located in Pune, Maharashtra. It was established in 1952 as the Virus Research Centre and now works under the Indian Council of Medical Research (ICMR). It is India’s apex virology laboratory and a WHO reference centre for several viruses.

ICMR Institutes:

Answer: (D) Goa

Explanation: The National Centre for Polar and Ocean Research (NCPOR) is located at Vasco da Gama, Goa. It was established in 1998 as the National Centre for Antarctic and Ocean Research and works under the Ministry of Earth Sciences. It manages India’s Antarctic, Arctic and Southern Ocean expeditions and the Indian research stations.

Ministry of Earth Sciences Institutes and Polar Research:

Answer: (A) IBM

Explanation: IBM (International Business Machines) is nicknamed “Big Blue”, reportedly because of its blue company logo and the blue-coloured mainframe cabinets and corporate dress style it was once known for. It was founded in 1911 as the Computing-Tabulating-Recording Company and renamed IBM in 1924.

Companies and Their Nicknames:

Answer: (A) S. N. Bose

Explanation: Satyendra Nath Bose developed Quantum Statistics in 1924 by deriving Planck’s law of black-body radiation using a new way of counting indistinguishable photons. He sent the work to Einstein, who extended it and translated the paper into German, giving rise to Bose-Einstein statistics. Particles that follow it are called bosons, named in his honour.

Indian Scientists:

Answer: (D) Thiruvananthapuram

Explanation: The Vikram Sarabhai Space Centre (VSSC) is located at Thumba, Thiruvananthapuram, Kerala. It began as the Thumba Equatorial Rocket Launching Station in 1963 and was renamed VSSC in 1972 in honour of Dr. Vikram Sarabhai. It is ISRO’s lead centre for designing and developing launch vehicles such as SLV, ASLV, PSLV and GSLV.

ISRO Centres:

Answer: (B) Kalpakkam

Explanation: The Indira Gandhi Centre for Atomic Research (IGCAR) is located at Kalpakkam, near Chennai, Tamil Nadu. It was established in 1971 as the Reactor Research Centre and renamed in 1985. It works under the Department of Atomic Energy and leads India’s fast breeder reactor programme, including the Prototype Fast Breeder Reactor (PFBR).

Department of Atomic Energy Institutions:

Answer: (A) Council of Scientific and Industrial Research

Explanation: CSIR stands for Council of Scientific and Industrial Research. It was established in 1942 and is India’s largest network of research laboratories. It is an autonomous body registered as a society, with the Prime Minister as its President.

CSIR Laboratories:

Answer: (B) 1 cm – 10 cm

Explanation: Super High Frequency (SHF) covers 3 GHz to 30 GHz, which corresponds to wavelengths of 1 cm to 10 cm. These short wavelengths allow narrow, directed beams, so SHF is widely used in radar, satellite communication, microwave links and Wi-Fi.

Radio Frequency Bands:

Answer: (A) MICR

Explanation: MICR (Magnetic Ink Character Recognition) is the technology banks use to read the special numbers printed at the bottom of cheques. These characters are printed in magnetic ink, which a MICR reader magnetises and scans quickly and accurately. It reduces manual errors and fraud in cheque processing. The MICR band carries the cheque number, MICR code (9-digit), account number and transaction code.

Input and Recognition Technologies:

Answer: (A) Multiplexors and routers

Explanation: A WAN (Wide Area Network) connects computers over large geographical areas such as cities, countries or continents. Its hardware includes multiplexors, routers, modems, switches and gateways, which carry and direct data over long distances using leased lines, satellites or public telecom networks. The internet is the largest example of a WAN.

Network Types and Hardware:

Answer: (B) Archie

Explanation: Archie, created in 1990 by Alan Emtage at McGill University, Canada, is regarded as the first internet search engine. It indexed file names on public FTP servers and did not search the content of web pages. Google came much later, in 1998.

Early Search Engines and Internet Tools:

Answer: (D) Prolog

Explanation: Prolog (Programming in Logic) was developed in 1972 and is widely used for artificial intelligence. It is a logic programming language based on facts and rules, which suits symbolic reasoning, expert systems and natural language processing. Lisp, created by John McCarthy in 1958, is the other classic AI language.

Programming Languages:

Answer: (D) 50 GB

Explanation: A dual-layer Blu-ray disc stores up to 50 GB of data, while a single-layer disc stores 25 GB. Blu-ray uses a blue-violet laser with a wavelength of 405 nm, which is shorter than the red laser used for DVDs, so the pits can be smaller and packed more densely.

Optical Discs:

Answer: (D) IRNSS

Explanation: IRNSS (Indian Regional Navigation Satellite System) is India’s own navigation satellite system, operationally named NavIC (Navigation with Indian Constellation). It has seven satellites (three in geostationary and four in inclined geosynchronous orbit) and provides accurate positioning over India and up to about 1,500 km beyond its borders.

Satellite Navigation Systems:

Answer: (D) Bandwidth

Explanation: Bandwidth is the amount of data that can be transmitted over a communication channel in a given amount of time. It is measured in bits per second (bps) for digital channels, and in hertz (Hz) for the range of frequencies an analog channel can carry. Higher bandwidth means faster data transfer.

Data Transmission Terms:

Answer: (B) VSB

Explanation: In analog TV transmission, the picture (video) signal is amplitude modulated using Vestigial Sideband (VSB) modulation. VSB sends one full sideband and only a vestige (part) of the other, which saves bandwidth compared with DSB while avoiding the complex filtering needed for pure SSB. The sound signal, in contrast, is frequency modulated.

Modulation Techniques:

Answer: (A) Vitamin A

Explanation: Golden rice is a genetically modified rice variety engineered to produce beta-carotene, which the human body converts into Vitamin A. It was developed to combat Vitamin A deficiency, a major cause of childhood blindness in rice-eating regions. Genes from daffodil (psy) and the bacterium Erwinia uredovora (crtI) were introduced to make the grains yellow-orange.

Biofortified and Genetically Modified Crops:

Answer: (B) bacteria

Explanation: Bt cotton is a transgenic crop that carries a gene from the soil bacterium Bacillus thuringiensis (Bt). The gene (cry1Ac) codes for a crystal protein that is toxic to bollworm larvae but harmless to humans. Bt cotton was approved in India in 2002 and is still the only GM crop grown commercially in the country.

Bt Crops and Transgenic Technology:

Answer: (B) Integrated Circuits

Explanation: IC stands for Integrated Circuit, a small chip in which many electronic components such as transistors, resistors and capacitors are fabricated on a single piece of semiconductor, usually silicon. Jack Kilby (Texas Instruments) built the first IC in 1958, and Robert Noyce developed the silicon-based version independently. ICs made computers smaller, faster and cheaper.

Generations of Computers and Electronic Components:

Answer: (A) Luna 10 (1966, USSR)

Explanation: Luna 10 was launched by the USSR in March 1966 and became the first spacecraft to orbit the Moon. Luna 1 (1959) was the first to fly past the Moon and Luna 2 (1959) was the first to hit its surface, but neither entered orbit. Luna 10 also transmitted data on the Moon’s magnetic field, gravity and radiation.

Lunar Missions:

Answer: (D) INS Arihant

Explanation: INS Arihant is India’s first indigenously built nuclear-powered ballistic missile submarine (SSBN). It was built under the secret Advanced Technology Vessel (ATV) project at Visakhapatnam, launched in 2009 and commissioned in 2016. Its commissioning gave India a sea-based leg of its nuclear triad.

Indian Naval Submarines:

Answer: (D) Indian Space Research Organisation

Explanation: ISRO stands for Indian Space Research Organisation. It was formed on 15 August 1969, replacing INCOSPAR (set up in 1962 under Vikram Sarabhai), and is headquartered in Bengaluru. It works under the Department of Space, which reports directly to the Prime Minister.

ISRO and the Indian Space Programme:

Answer: (B) Vital Information Resources Under Siege

Explanation: The term VIRUS in computing stands for Vital Information Resources Under Siege. It refers to a type of malicious software (malware) designed to replicate itself by altering other computer programs and inserting its own code. When a computer is infected, its “vital resources”—such as data, memory, processing power, and system files—are considered to be “under siege” or under attack by the program.

Computer Virus and Malware Terms:

Answer: (C) Radio Detecting and Ranging

Explanation: RADAR stands for Radio Detecting and Ranging (often written Radio Detection and Ranging). It sends out radio or microwave pulses and measures the echo reflected from an object to find its distance, direction and speed. The term was coined by the US Navy in 1940, and radar was developed extensively during World War II.

Radar and Remote Sensing Terms:

Answer: (A) February, 2010

Explanation: India’s first scientific expedition to Antarctica (the South Pole region) was launched in December 1981 and reached in January 1982, led by Dr. S. Z. Qasim. Among the given options, the one matching the official answer key for this question is February 2010, which is the option quoted in exam sources. Treat this as a question where the options do not match the historical record, and remember the actual date of 1981 for factual questions.

Indian Antarctic Programme:

Answer: (A) INS Kamorta

Explanation: INS Kamorta is India’s first indigenously designed and built anti-submarine warfare (ASW) corvette. It was built by Garden Reach Shipbuilders and Engineers (GRSE), Kolkata, under Project 28, and commissioned in August 2014. It is the lead ship of the Kamorta class and is named after Kamorta island in the Nicobar group.

Indian Naval Warships:

Answer: (C) July 12, 2010

Explanation: PSLV-C15 was launched successfully on 12 July 2010 from Sriharikota. It carried Cartosat-2B, an Indian remote sensing satellite, along with other small satellites including AlSat-2A (Algeria), two nano-satellites from Switzerland and Canada, and a Studsat from Indian universities. Studsat was India’s first student-built satellite.

PSLV Launches:

Answer: (D) 24 hours

Explanation: A geostationary satellite has an orbital period equal to Earth’s rotation period, about 24 hours (23 h 56 min, the sidereal day). It orbits at roughly 35,786 km above the equator, in the same direction as Earth’s rotation, so it appears fixed over one point. This makes it ideal for communication and weather satellites.

Satellite Orbits:

Answer: (C) Kalpakkam

Explanation: Among the given options, Kalpakkam (Tamil Nadu) is the one that hosts an atomic power station, the Madras Atomic Power Station (MAPS), which has two 220 MWe PHWR units commissioned in 1984 and 1986. Hyderabad, Bengaluru and Trivandrum have nuclear or space research and fuel facilities, but no atomic power station.

Indian Nuclear Power Stations:

Answer: (D) Microwave

Explanation: Pasteurization kills disease-causing microbes in milk by heating it, and among the given options only microwave is a heating method (microwave volumetric heating). Ozone, UV rays and chlorine are disinfectants, not the standard way to pasteurize milk. Louis Pasteur developed the process in the 1860s, and conventional dairies mostly use steam or hot-water heat exchangers, as in HTST.

Milk Pasteurization and Food Preservation:

Answer: (C) A set of instructions for your computer

Explanation: Software is a set of instructions, or programs, that tells computer hardware what to do. It cannot be touched, unlike hardware. The two main types are system software, which runs the computer itself, and application software, which helps users perform specific tasks.

Types of Software:

Answer: (A) System

Explanation: The operating system is the most common type of system software. It manages hardware resources such as the CPU, memory, storage and input/output devices, and provides a platform on which application software runs. Examples include Windows, Linux, macOS, Android and iOS.

System Software:

Answer: (C) operating system

Explanation: Booting is the process of loading the operating system into main memory when a computer is switched on. At power-on, the BIOS/UEFI firmware runs a self-test (POST) and then uses a bootstrap loader to find and load the OS from storage. Without an operating system, the computer can complete the hardware checks but cannot start up for the user.

Booting Process:

Answer: (B) C-DAC

Explanation: PARAM, India’s series of supercomputers, was developed by C-DAC (Centre for Development of Advanced Computing), Pune. The first machine, PARAM 8000, was unveiled in 1991 under the leadership of Dr. Vijay P. Bhatkar. C-DAC was set up in 1988 after India was denied a Cray supercomputer by the USA.

Indian Supercomputers:

Answer: (A) 30 – 300 MHz

Explanation: Television broadcasting normally uses the VHF band (30 – 300 MHz) and the UHF band (300 MHz – 3 GHz). Among the given options, 30 – 300 MHz is the correct range, as VHF carries most conventional TV channels along with FM radio. The GHz range is used for satellite links, and the kHz and Hz ranges are far too low for TV signals.

TV Broadcasting Bands:

Answer: (B) Digital circuits

Explanation: Modern communication systems are based mainly on digital circuits. Digital signals resist noise, can be error-checked and corrected, compressed, encrypted and multiplexed easily, and can be regenerated without loss over long distances. Mobile networks (4G/5G), the internet, digital TV and satellite links all use digital transmission. Analog circuits still appear at the front end, such as in antennas, amplifiers and microphones.

Analog vs Digital Communication:

Answer: (A) doped semiconductors

Explanation: A transistor is made of doped semiconductors, usually silicon, arranged as three regions (emitter, base and collector) forming two p-n junctions. Doping with impurities creates n-type and p-type regions, which lets the device amplify signals or act as a switch. A transistor does not use a metal piece sandwiched between intrinsic semiconductors, and intrinsic (pure) semiconductors alone cannot form junctions.

Semiconductor Devices:

Answer: (B) Telephone

Explanation: A carbon microphone is best used in a telephone. It has carbon granules held between a diaphragm and a metal plate. Sound waves change the pressure on the granules, which changes their electrical resistance and so varies the current in the circuit. It was widely used in telephone transmitters from the late 1800s because it produces a strong signal without needing an amplifier. A dynamo and a transformer have no use for a microphone.

Microphones and Telephone Components:

Answer: (B) frequency modulation

Explanation: In television broadcasting, the audio (sound) signal is transmitted using frequency modulation (FM), while the picture signal uses amplitude modulation (VSB). FM gives good noise immunity and high-quality sound. In analog TV the sound carrier is placed 5.5 MHz above the picture carrier in the 7 MHz channel used in India (PAL-B/G system).

TV Signal Transmission:

Answer: (B) IPV4

Explanation: IPv4 (Internet Protocol version 4) is the most widely deployed internet layer protocol. It uses 32-bit addresses, giving about 4.3 billion unique addresses, written in dotted decimal form such as 192.168.1.1. IPv6 was introduced to overcome address exhaustion, but IPv4 still carries most internet traffic. IPv2, IPv3 and IPv5 were never deployed for general use, and IPv8 does not exist as a standard.

Internet Protocol Versions and Related Protocols:

Answer: (D) All of these

Explanation: Aliweb, Jughead and Baidu are all web or internet search engines. Aliweb (1994) was one of the first web search engines, Jughead (1993) searched Gopher directories, and Baidu (2000) is the leading Chinese search engine. Since each option is a search tool, “All of these” is correct.

Search Engines:

Answer: (A) George Devel

Explanation: In 1954, American inventor George Devol invented and patented the world’s first digitally operated, programmable robotic arm called the Unimate (derived from “Universal Automation”). His patent laid the foundational architecture for the entire modern robotics industry.

Context of the Other Options:

• Joseph Engelberger: Met George Devol in 1956. Together, they formed Unimation, the world’s first commercial robotics company. Because Engelberger successfully modified, marketed, and deployed the Unimate factory robot at a General Motors plant in 1961, he is celebrated globally as the “Father of Robotics”.
• Karel Čapek: The Czech writer who originally coined the word “robot” in his 1920 sci-fi play R.U.R. (Rossum’s Universal Robots).
• Hisashige Tanaka: A historic 19th-century Japanese inventor famous for creating intricate mechanical dolls (karakuri ningyo) and clocks, which were purely mechanical automatons rather than digital or programmable electronics.

Answer: (A) Computer

Explanation: Spam is related to computers, as it means unsolicited bulk messages, usually email, sent to many people at once. It is often used for advertising, scams and phishing, or to spread malware. The term is said to come from a Monty Python sketch in which the word “Spam” (a canned meat brand) is repeated endlessly. Email providers use spam filters to separate such messages from genuine mail.

Spam and Email Threats:

Answer: (D) Spam

Explanation: Junk e-mail is also called spam. It refers to unsolicited, usually bulk, messages sent to many recipients for advertising, scams or phishing. Spoof means faking a sender’s identity, spool refers to queuing data for a device such as a printer, and a sniffer script captures network data, so none of these means junk mail.

Email and Messaging Terms:

Answer: (B) Computer virus

Explanation: A computer virus is a set of program instructions that attaches itself to a file, reproduces itself and spreads to other files when the infected file is run. It needs a host file and some user action to spread. A worm spreads on its own over networks without needing a host file, a Trojan horse disguises itself as useful software and does not replicate, and phishing is a fraud technique rather than a program.

Types of Malware:

Answer: (C) Mouse

Explanation: The mouse is the most common pointing/picking device used in graphic applications. It lets the user select objects, click icons and draw on screen by moving a cursor. Graphic tablets, joysticks and light pens are also picking or pointing devices, but they are used in specialised work and are far less common.

Input and Pointing Devices:

Answer: (B) UHF

Explanation: The UHF band (300 MHz to 3 GHz) is used for radar, relay systems and television. Its short wavelengths (1 m to 10 cm) allow compact antennas and line-of-sight links, so it suits TV broadcasting, microwave relay and radar. VLF and EHF are not used for TV, and VHF is mainly used for FM radio and TV channels, so UHF is the best match for a combined radar relay and TV role.

Frequency Bands:

Answer: (A) Marisat (USA, 1973)

Explanation: Marisat was the first maritime communications satellite system, launched by the USA in 1976 (the question’s key notes 1973 as the planning year). It provided ship-to-shore, shore-to-ship and ship-to-ship communication and later led to Inmarsat, which began operations in 1982. Comsat is the US company that managed American satellite communications, Telstar was an early experimental communication satellite, and Intelsat serves international telephone and TV links.

Satellite Communication Systems:

Answer: (A) Maharashtra

Explanation: India officially entered the 3G telecommunications arena on 11 December 2008, when the government-owned public sector operator Mahanagar Telephone Nigam Ltd (MTNL) launched the country’s first 3G-enabled mobile and data services.

• Subsequent Expansion: Following MTNL’s initial rollout, the other state-owned operator, Bharat Sanchar Nigam Ltd (BSNL), expanded 3G connectivity across the rest of the nation starting in early 2009. Private telecom operators (like Tata DoCoMo and Reliance Communications) were allocated spectrum later and began launching their services in late 2010.
• The Initial Launch: The services were initially rolled out in the metropolitan areas under MTNL’s jurisdiction—Delhi and Mumbai (located in the state of Maharashtra).

Answer: (D) Communication Technology

Explanation: WiMAX (Worldwide Interoperability for Microwave Access) is a wireless broadband communication technology based on the IEEE 802.16 standard. It was designed to deliver high-speed internet over long distances, up to about 50 km for fixed access, and served as a wireless alternative to cable and DSL. It has no connection with biotechnology, space technology or missile technology.

Wireless Communication Technologies:

Answer: (D) Light Storage

Explanation: “Light Storage” is not a standard term of Information Technology. Cyberspace means the virtual environment of computer networks and the internet, upload means sending a file from a local device to a remote server, and a modem is a device that converts digital signals to analog and back for transmission over telephone or cable lines.

IT Terms:

Answer: (A) South Korea

Explanation: South Korea is credited with first deploying 4G (mobile WiMAX/WiBro) commercially in 2006, and the question’s answer key follows this. Note that the first commercial LTE services were launched by TeliaSonera in Stockholm and Oslo in December 2009, so sources differ depending on whether WiMAX or LTE is counted as 4G. Among the given options, South Korea is the exam answer.

Mobile Generations and Firsts:

Answer: (C) A word processing software

Explanation: Microsoft Office Word is a word processing application used to create, edit, format and print text documents such as letters, reports and resumes. It is application software, not an operating system, and it is not an input device. It offers features like spell check, tables, mail merge, headers and footers, and templates. Word was first released by Microsoft in 1983.

Microsoft Office Applications:

Answer: (B) Linux OS

Explanation: Linux is the operating system used by almost all of the world’s Top 500 supercomputers, and it has run on every one of them since 2017. It is open source, can be freely modified and tuned for high-performance clusters, scales across thousands of processors, and has no licence cost. Unix was used earlier, but it has been almost entirely replaced by Linux in this list.

Operating Systems:

Answer: (B) Power Point

Explanation: Microsoft PowerPoint is the application commonly used to prepare presentations or slide shows. It lets users build slides with text, images, charts, animations and transitions, and present them on a screen or projector. Photoshop is for image editing, Internet Explorer is a web browser, and Outlook Express is an email client.

Presentation and Graphics Software:

Answer: (D) System disc

Explanation: A cold boot is starting a computer from a powered-off state, and it needs a system disc (a bootable disc holding the operating system’s startup files) to load the OS into memory. A set-up disc installs software, a program disc holds application programs, and a diagnostic disc is used to test and troubleshoot hardware faults.

Types of Discs and Booting:

Answer: (B) Sky wave

Explanation: Long-distance short wave (HF, 3 – 30 MHz) radio broadcasting uses sky wave propagation. The waves travel upward, are refracted back to Earth by the ionosphere, and can hop between the ground and the ionosphere several times, covering thousands of kilometres. Ionospheric wave is another name for the same mechanism, but sky wave is the standard term. Ground waves die out within a short distance at these frequencies, and direct waves need a line of sight.

Radio Wave Propagation:

Answer: (D) All of these

Explanation: Wi-Fi is a wireless networking technology built into many kinds of devices. Smartphones use it to connect to the internet, video game consoles use it for online play and downloads, and modern computer printers include Wi-Fi so they can print wirelessly from phones and laptops. Since all three options are correct, “All of these” is the answer.

Wi-Fi Standards and Devices:

Answer: (C) Light-emitting diode display (LED)

Explanation: An LED display works on the principle of semiconductors. Each pixel (or backlight element) is a light-emitting diode, a p-n junction that gives off light when current passes through it in the forward direction. A plasma display lights up ionised gas, a liquid crystal display controls light with liquid crystals and needs a separate backlight, so only the LED display depends directly on semiconductor junctions.

Television Display Technologies:

Answer: (B) Constantin Perskyi

Explanation: The word “television” was coined by Constantin Perskyi, a Russian scientist, in a paper presented at the first International Congress of Electricity in Paris in August 1900. He combined the Greek “tele” (far) with the Latin “visio” (sight). Paul Nipkow had earlier invented the Nipkow disk (1884), a mechanical scanning device, but he did not coin the term.

Television History:

Answer: (A) Clive Sinclair (UK – 1977)

Explanation: Sir Clive Sinclair, a British inventor, sold the world’s first mobile (pocket) television, the MTV-1 “Microvision”, in 1977. It was a small handheld set with a 2-inch CRT screen. It was a commercial failure because of its high price and poor reception, but it paved the way for later pocket TVs, including the Sinclair TV80 (1983), which used a flat CRT.

Sinclair and Portable Electronics:

Answer: (D) OLEDS

Explanation: A Light-emitting Electrochemical Cell (LEC or LEEC) is closely related to an Organic Light-Emitting Diode (OLED), as both are solid-state lighting devices that utilize organic semiconductors to emit light.

However, an LEC represents a fundamentally different mode of electrical operation:

• The Advantage: This unique mode of operation makes LECs highly tolerant to thickness variations. Consequently, they can be printed cheaply using simple air-ambient methods, unlike OLEDs which require rigid, high-vacuum manufacturing conditions.
• The Mechanism: Unlike standard OLEDs that require a complex stack of multiple precisely layered materials (such as electron-transporting, hole-transporting, and emission layers), an LEC uses a single-layer blend containing mobile ions.
• Dynamic Junction: When a voltage is applied to an LEC, these mobile ions migrate to the opposite electrodes. This dynamic rearrangement creates an in-situ p-n junction right inside the material.

Answer: (C) UMTS

Explanation: LTE (Long Term Evolution) was developed by 3GPP as the upgrade path for GSM/UMTS networks, and it also became the upgrade route for CDMA2000 networks. Among the given options, UMTS (the 3G technology that evolved from GSM) is the one LTE directly builds on. Wi Man is not a standard, CDMA is a separate technology family, and HSDPA is only a 3G data enhancement within UMTS.

GSM Technology Evolution:

Answer: (B) Radio Waves

Explanation: Bluetooth exchanges data over short distances using short-wavelength radio waves in the 2.4 GHz ISM band (2.400 to 2.485 GHz). Although this frequency lies within the microwave range, it is classified as radio waves, and it is the standard answer for this question. It uses frequency-hopping spread spectrum to reduce interference, and typical range is about 10 m for Class 2 devices.

Bluetooth and Short-Range Wireless:

Answer: (B) NTT DoCoMo (Japan) (1998)

Explanation: NTT DoCoMo of Japan launched the world’s first commercial 3G network in October 2001 under the brand name FOMA, using WCDMA technology. The question’s key lists 1998, which is when DoCoMo began its 3G trials and standards work, so this is the exam answer. In India, MTNL launched 3G in Delhi and Mumbai in 2008, and Bharti Airtel launched 4G in Kolkata in 2012.

3G Launches and Operators:

Answer: (D) All of these

Explanation: Google Chrome, Safari and Opera are all web browsers, which are programs used to access and display pages on the World Wide Web. Chrome was released by Google in 2008, Safari by Apple in 2003, and Opera by Opera Software in 1995. Since every option is a browser, “All of these” is correct.

Web Browsers:

Answer: (C) Intercontinental communication

Explanation: Intelsat (International Telecommunications Satellite Organization) was set up in 1964 to provide global commercial satellite communication. Its geostationary satellites relay telephone, TV and data traffic between continents, for example across the Atlantic, Pacific and Indian Ocean regions. The first satellite, Intelsat I (Early Bird), was launched in 1965. Radar and radio communication are not its specific role, so intercontinental communication is the best answer.

Intelsat and International Satellite Organisations:

Answer: (C) Either of the above

Explanation: A modem (modulator-demodulator) converts digital signals from a computer into analog signals for transmission over telephone or cable lines (modulation), and converts incoming analog signals back to digital form (demodulation). Option (A) as written reverses the direction, and (B) describes only half of the job, but since the device handles signal conversion in both directions, the exam answer is “Either of the above”.

Modems and Network Devices:

Answer: (D) Cholesteric Display

Explanation: A cholesteric display (cholesteric liquid crystal display) is non-volatile: it keeps its image without power and needs electricity only when the image changes. Plasma, LCD and OLED displays are volatile, because the image disappears as soon as power is removed. Cholesteric displays are used in e-paper-type applications such as electronic signs and e-readers.

Volatile vs Non-Volatile Displays:

Answer: (C) UNIVAC-1 (USA in 1951)

Explanation: UNIVAC I (Universal Automatic Computer I) was the first commercially produced computer in the USA, delivered to the US Census Bureau in 1951. It was designed by J. Presper Eckert and John Mauchly, the creators of ENIAC. The Ferranti Mark 1 (1951, UK) is also described as the first commercially available general-purpose computer, but the exam answer key follows UNIVAC-1 given in the option.

Early Computers:

Answer: (A) 88 MHz to 108 MHz

Explanation: Commercial FM radio broadcasting uses the 88 MHz to 108 MHz range, which lies in the VHF band. FM stations are spaced 200 kHz apart in this range, and the waves travel by line of sight, so the range of a station is limited to roughly 50 to 100 km. The GHz range is used for satellite and microwave links, and the kHz range is used for AM and navigation.

Radio Broadcasting Bands:

Answer: (D) Lisp

Explanation: Lisp is not generally classed as a scripting language. It is a general-purpose, high-level language created by John McCarthy in 1958 and used mainly for artificial intelligence and symbolic processing. JavaScript, Python (spelt “Pytheon” in the option) and Perl are all well-known scripting languages, used for web pages, automation and text processing.

Scripting and Programming Languages:

Answer: (C) Matti Makkonen

Explanation: Matti Makkonen, a Finnish engineer, is called the “Father of SMS” because he proposed the idea of the Short Message Service in 1984 and helped develop it as part of the GSM standard. The first SMS was sent in December 1992 by Neil Papworth, and SMS messages are limited to 160 characters. Jamie Lannister is a fictional character from Game of Thrones, and Ross Bolton is also a fictional character from the same story.

SMS and Mobile Messaging:

Answer: (B) Konard Zuse (1943-45)

Explanation: Konrad Zuse, a German engineer, created Plankalkül between 1943 and 1945, which is regarded as the first high-level programming language designed for computers. It included features such as assignment, subroutines, conditionals and even a chess program. It was not implemented on a computer until 1975, long after its design, so FORTRAN (1957) became the first high-level language widely used in practice.

Pioneers of Programming and Computing:

Answer: (D) Claude E Shannon

Explanation: Claude E. Shannon first used the term “bit” (binary digit) in print in his 1948 paper “A Mathematical Theory of Communication”, which founded information theory. He credited the word to his colleague John W. Tukey, who coined it. A bit is the basic unit of information and holds a value of 0 or 1. Shannon is called the “Father of Information Theory”.

Information Theory and Data Units:

Answer: (B) SRAM

Explanation: SRAM (Static RAM) is volatile memory: it keeps data only while power is supplied and loses it when power is switched off. The question asks which is not non-volatile, so SRAM is the answer. PRAM (phase-change RAM), flash memory and bubble memory all retain data without power. SRAM is faster than DRAM and is used for CPU cache memory.

Volatile and Non-Volatile Memory:

Answer: (C) Semiconductor laser

Explanation: A laser printer uses a semiconductor (diode) laser. The laser beam is switched on and off according to the image data and sweeps across a rotating, electrically charged photoreceptor drum using a spinning mirror. Where the beam hits, the charge is removed, toner sticks to those spots, and heat and pressure then fuse the toner onto the paper. The semiconductor laser is small, cheap, efficient and easy to modulate, which suits printers.

Laser Types and Applications:

Answer: (C) MIPS

Explanation: MIPS (Million Instructions Per Second) is the term used to compare the processing speed of computers. It measures how many millions of instructions a processor can execute in one second. It is useful only as a rough guide, because instructions differ in complexity between processor designs. MPG (miles per gallon) measures fuel efficiency, and CPS (characters per second) measures printer speed.

Computer Performance Measures:

Answer: (C) Karnataka

Explanation: Bengaluru in Karnataka is known as the “Silicon Valley of India”. It is India’s largest IT hub, home to Infosys, Wipro and many global technology firms, as well as ISRO, DRDO and HAL. The title comes from the concentration of IT companies and talent, as in California’s Silicon Valley.

IT Hubs and Technology Parks in India:

Answer: (C) Page Printer

Explanation: A laser printer is a page printer because it processes and prints one complete page at a time. The page image is built in the printer’s memory, then transferred by the laser to the drum and onto the paper in a single pass. Line printers print one line at a time, and dot-matrix printers print character by character using a moving print head.

Printer Types:

Answer: (B) Digital circuit

Explanation: An encoder is a combinational digital circuit that converts 2^n input lines into an n-bit binary output code. Only one input is active at a time, and the circuit outputs the binary code for that input. For example, a 4-to-2 encoder turns four input lines into a 2-bit code. It may be built as an IC, but its basic nature is a digital circuit, and it is the reverse of a decoder.

Digital Logic Circuits:

Answer: (D) A multi satellite navigation project developed by the European Union

Explanation: The Galileo Project is the European Union’s global navigation satellite system (GNSS), run by the European Space Agency and the European GNSS Agency. It is a civilian-controlled alternative to the US GPS, Russia’s GLONASS and China’s BeiDou. The first test satellite, GIOVE-A, was launched in 2005, and the system began offering initial services in 2016. It plans a constellation of 30 satellites (24 operational and 6 spares) in medium Earth orbit at about 23,222 km.

Global and Regional Navigation Systems:

Answer: (D) Tempel-1 (2005)

Explanation: NASA’s Deep Impact mission, launched in January 2005, sent an impactor probe to hit the nucleus of comet Tempel 1 on 4 July 2005. The collision threw out material that the flyby spacecraft photographed and analysed, giving scientists a look at the comet’s interior. The mission showed the nucleus is made of a dusty, porous material with water ice beneath the surface. The flyby craft was later reused as EPOXI to visit comet Hartley 2 in 2010.

Comet and Space Probe Missions:

Answer: (B) Cassini

Explanation: Cassini (Cassini-Huygens) was a NASA, ESA and Italian Space Agency spacecraft launched in 1997 to study Saturn, its rings and moons. It entered Saturn’s orbit in 2004, released the Huygens probe that landed on Titan in January 2005, and ended its mission in September 2017 by plunging into Saturn’s atmosphere. Apophis is an asteroid, Spitzer is a space telescope rather than a planetary spacecraft, and TechSAR is an Israeli radar-imaging satellite.

Notable Spacecraft and Space Objects:

Answer: (D) Provides the necessary acceleration for its motion

Explanation: An artificial satellite stays in orbit because it is in a state of perpetual free-fall toward the planet. When the satellite is launched, it is given a massive tangential (sideways) velocity.

• The Resulting Path: This acceleration doesn’t change the forward speed of the satellite in a stable circular orbit; instead, it constantly bends its direction. As a result, the satellite continuously falls around the curve of the Earth rather than falling down onto it.
• Role of Gravity: The Earth’s gravitational pull acts as a centripetal force.
• Directional Change: According to Newton’s Second Law of Motion (F=ma), this net gravitational force continuously provides a centripetal acceleration directed toward the center of the Earth.

Answer: (D) Altering human beings by changing their genetic components.

Explanation: Eugenics is the study and practice of improving the genetic quality of the human population, either by encouraging reproduction among people with desired traits (positive eugenics) or by discouraging it among those with undesired traits (negative eugenics). The term was coined by Francis Galton in 1883. The movement is now widely discredited because of its links to forced sterilisation and Nazi racial policies. Modern gene editing debates sometimes revive the term.

Eugenics and Human Genetics:

Answer: (A) Nuclear Magnetic Resonance

Explanation: MRI (Magnetic Resonance Imaging) works on the principle of Nuclear Magnetic Resonance (NMR). The patient is placed in a strong magnetic field, which aligns the spinning hydrogen nuclei (protons) in body water and fat. A radio-frequency pulse knocks them out of alignment, and as they relax back they emit signals that a computer converts into detailed images. MRI uses no ionising radiation, unlike X-rays and CT scans.

Medical Imaging Techniques:

Answer: (B) Bacillus thuringiensis

Explanation: In Bt cotton, “Bt” stands for Bacillus thuringiensis, a soil bacterium. Its cry genes (such as cry1Ac) code for crystal proteins that are toxic to bollworm larvae. The gene was transferred into cotton to give built-in resistance to bollworms. The protein is harmless to humans, and Bt cotton has been grown in India since 2002.

Bt Technology:

Answer: (A) ROM

Explanation: ROM (Read-Only Memory) is the storage medium that usually cannot be modified. Its contents are written during manufacture and hold permanent instructions, such as the startup program (BIOS/firmware) that runs when the computer is switched on. It is non-volatile, so data stays without power. RAM is read-write and volatile, and hard disks and flash drives can be rewritten freely.

Computer Memory and Storage:

Answer: (A) charge coupled device

Explanation: CCD stands for Charge Coupled Device, a light-sensitive semiconductor chip that converts light into electrical charge. It is divided into a grid of tiny pixels, and the charge collected in each pixel is shifted out and read to build a digital image. CCDs are used in digital cameras, camcorders, scanners and telescopes. It was invented in 1969 by Willard Boyle and George Smith at Bell Labs, who shared the Nobel Prize in Physics in 2009.

Image Sensors and Imaging Devices:

Answer: (B) methane

Explanation: India’s Mars Orbiter Mission (Mangalyaan), launched in November 2013 and placed in Mars orbit in September 2014, carries a Methane Sensor for Mars (MSM) to look for methane in the Martian atmosphere. On Earth, most methane is produced by living organisms, so its presence on Mars could point to biological activity, though geological processes can also produce it. Oxygen, carbon dioxide and sulphur dioxide are not used as the key indicator of life for this mission.

Mars Orbiter Mission:

Answer: (A) water is a polar molecule

Explanation: Microwave ovens produce microwaves at about 2.45 GHz. Water molecules are polar, with a slightly positive hydrogen end and a slightly negative oxygen end, so they try to align with the rapidly changing electric field of the microwaves. This constant rotation causes friction between molecules, which produces heat. Fats and sugars also absorb microwaves to a lesser extent, while dry materials such as glass and ceramic mostly do not heat.

Microwave Oven:

Answer: (D) Hyper Text Transfer Protocol

Explanation: HTTP stands for Hyper Text Transfer Protocol. It is the application-layer protocol used by web browsers and servers to request and send web pages and other resources on the World Wide Web. It works on a request-response model and is stateless, meaning each request is treated independently. It uses port 80 by default, and its secure version, HTTPS, uses TLS encryption on port 443. Tim Berners-Lee developed HTTP at CERN around 1989-91.

Web Protocols and Terms:

Answer: (C) Office Suite

Explanation: Office Suite is not a programming language. It is a bundle of application software (word processor, spreadsheet, presentation and database programs) such as Microsoft Office or LibreOffice. C++, Java and Fortran are all programming languages used to write software.

Programming Languages vs Software Suites:

Answer: (C) 8

Explanation: A byte is a group of 8 bits. It is the basic unit used to measure computer memory and storage, and one byte can represent a single character, such as a letter or digit, in the ASCII code. It can hold 256 different values (2^8). The term “byte” was coined by Werner Buchholz at IBM in 1956.

Data Units:

Answer: (A) binary

Explanation: A digital adder built from logic gates works in the binary number system, because logic gates handle only two voltage levels, representing 0 and 1. A half adder adds two bits using an XOR gate for the sum and an AND gate for the carry. A full adder adds two bits plus a carry-in, and several full adders are chained to add multi-bit numbers.

Binary Addition and Adder Circuits: