विज्ञान और प्रौद्योगिकी (बुनियादी)

हिंदी में पढ़ें

Science & Technology — From a Bicycle Rocket to the Moon's South Pole

◆ On 21 November 1963, a small sounding rocket lifted off from Thumba, a fishing village near Thiruvananthapuram in Kerala. A church there served as an early office, and an old photograph shows a rocket part being carried on a bicycle. Sixty years later, on 23 August 2023, India's Vikram lander touched down near the south pole of the Moon — no country had landed there before. Between the bicycle and the Moon lies the story of this chapter: inventions, discoveries, units, computers, space, defence and the institutions that made it all happen. Exams love this chapter because almost every question is a clean, one-line fact. Learn it well and it becomes a sure-shot scoring area.

What you will learn (Learning Objectives)

Famous inventions and discoveries, and the people behind them — without mixing up look-alike names

Indian scientists, their work and the Nobel prizes linked to India

SI units — the 7 base units, common derived units and special units like light-year and knot

Computer basics — parts, memory, generations, data units and common abbreviations

India's space programme from INCOSPAR (1962) to Chandrayaan-3 (2023), Aditya-L1 and later missions, with dates

Nuclear and defence milestones — Pokhran, BARC, DRDO and its missiles

Major scientific institutions and their cities, and the important "science days"

Part A — Inventions and Discoveries

1. Famous Inventions (Inventor)

Telephone — Alexander Graham Bell (1876)
Electric bulb (practical incandescent lamp) — Thomas Alva Edison (1879)
Aeroplane (first powered flight) — Wright brothers, Orville and Wilbur (1903)
Television (first public demonstration) — John Logie Baird (1926)
Radio (wireless telegraphy) — Guglielmo Marconi
Printing press with movable metal type — Johannes Gutenberg (about 1440)
Steam engine (improved, efficient version) — James Watt
Dynamite — Alfred Nobel (1867); his will created the Nobel Prizes, first given in 1901
Electric battery (voltaic pile) — Alessandro Volta (1800)
Barometer — Evangelista Torricelli
Electromagnetic induction (basis of the generator/dynamo) — Michael Faraday (1831)
Crescograph (measures plant growth) — Jagadish Chandra Bose
Handheld mobile phone (first call, 1973) — Martin Cooper
Computer mouse — Douglas Engelbart
World Wide Web — Tim Berners-Lee (1989, at CERN)

🧠 Active Recall: Who invented the telephone, and who demonstrated television first? (Graham Bell; John Logie Baird.)

2. Great Discoveries

Structure of the atom (NCERT Class 9):
Electron — J. J. Thomson (1897)
Atomic nucleus (gold-foil experiment) — Ernest Rutherford (1911)
Neutron — James Chadwick (1932)

Radiation:
X-rays — Wilhelm Röntgen (1895)
Radioactivity — Henri Becquerel (1896)
Radium and polonium — Marie Curie and Pierre Curie

Medicine and biology:
Smallpox vaccine — Edward Jenner (1796)
Rabies vaccine and pasteurisation — Louis Pasteur
Penicillin, the first antibiotic — Alexander Fleming (1928)
Polio vaccine — Jonas Salk (injected, killed virus); Albert Sabin (oral)
Bacteria of tuberculosis and cholera — Robert Koch
Circulation of blood — William Harvey (1628)
Blood groups (A, B, O) — Karl Landsteiner
Insulin — Frederick Banting and Charles Best (1921)
Laws of heredity (pea plants) — Gregor Mendel
Theory of evolution by natural selection — Charles Darwin
Double-helix structure of DNA — James Watson and Francis Crick (1953)
Periodic table (1869) — Dmitri Mendeleev
Cell (in cork) — Robert Hooke (1665); cell nucleus — Robert Brown (1831)

Memory trick — "Mendel's peas, Mendeleev's elements": the shorter name grew peas in a garden; the longer name arranged the longer list — the elements.

🧠 Active Recall: Who discovered the neutron, and who discovered the electron? (Chadwick; J. J. Thomson.)

3. Indian Scientists and their Work

C. V. Raman — Raman Effect (scattering of light), announced on 28 February 1928; Nobel Prize in Physics, 1930. 28 February is National Science Day.
Jagadish Chandra Bose — showed that plants respond to stimuli; invented the crescograph; pioneer of radio/microwave research.
Srinivasa Ramanujan — mathematician; 1729 is called the Hardy–Ramanujan number; his birthday, 22 December, is National Mathematics Day.
Satyendra Nath Bose — Bose–Einstein statistics; the particles called "bosons" are named after him.
Meghnad Saha — Saha ionisation equation (astrophysics).
Homi J. Bhabha — father of India's nuclear programme; founded TIFR (1945).
Vikram Sarabhai — father of India's space programme; founded PRL, Ahmedabad (1947).
A. P. J. Abdul Kalam — "Missile Man of India"; project director of SLV-3; led the Integrated Guided Missile Development Programme; 11th President of India.
M. S. Swaminathan — leading scientist of India's Green Revolution.
Verghese Kurien — "Father of the White Revolution" (Operation Flood).

Nobel Prizes in science linked to India:
C. V. Raman — Physics, 1930 (Indian citizen)
Har Gobind Khorana — Physiology or Medicine, 1968 (Indian-born; genetic code)
Subrahmanyan Chandrasekhar — Physics, 1983 (Indian-born; Chandrasekhar limit for white dwarf stars)
Venkatraman Ramakrishnan — Chemistry, 2009 (Indian-born; structure of the ribosome)

🧠 Active Recall: Which day is National Science Day, and why? (28 February — Raman Effect, 1928.)

Part B — Units of Measurement

4. SI Base Units (7)

Quantity — Unit (symbol)
Length — metre (m)
Mass — kilogram (kg)
Time — second (s)
Electric current — ampere (A)
Temperature — kelvin (K)
Amount of substance — mole (mol)
Luminous intensity — candela (cd)

Mnemonic: "My Kind Sister Always Keeps Mangoes Cool" — metre, kilogram, second, ampere, kelvin, mole, candela.

5. Common Derived Units

Force — newton (N) | Work/energy — joule (J) | Power — watt (W) | Pressure — pascal (Pa)
Frequency — hertz (Hz) | Electric charge — coulomb (C) | Potential difference — volt (V)
Resistance — ohm (Ω) | Capacitance — farad (F) | Inductance — henry (H)
Magnetic flux — weber (Wb) | Magnetic field (flux density) — tesla (T)
Power of a lens — dioptre (D)

6. Special Units and Conversions

Light-year — a unit of DISTANCE (distance light travels in one year, about 9.46 × 10^15 m), not of time.
Parsec — also a unit of distance in astronomy.
Angstrom (Å) — 10^-10 m; used for very small lengths such as wavelengths.
Knot — speed of ships and aircraft (1 nautical mile per hour).
Decibel (dB) — sound level (loudness).
Fathom — depth of water.
1 horsepower — about 746 watt.
1 kilowatt-hour (1 "unit" of electricity) — 3.6 × 10^6 joule.
0 K = -273.15 °C; 0 °C = 273.15 K.
Celsius and Fahrenheit show the same reading at -40.
Normal body temperature — 37 °C = 98.6 °F.

🧠 Active Recall: Is a light-year a unit of time or distance? Name the SI unit of pressure. (Distance; pascal.)

Part C — Computer Basics

7. Parts of a Computer

CPU (Central Processing Unit) — the "brain" of the computer. It has the ALU (Arithmetic Logic Unit), which does calculations and comparisons, and the CU (Control Unit), which directs all other parts.
Input devices — keyboard, mouse, scanner, microphone, joystick, light pen.
Output devices — monitor, printer, speaker, plotter, projector.
Memory:
RAM (Random Access Memory) — main working memory; volatile (data is lost when power goes off).
ROM (Read Only Memory) — non-volatile; holds start-up instructions.
Cache — very fast, small memory between the CPU and RAM.
Secondary storage — hard disk, SSD, pen drive, CD/DVD; keeps data permanently.
Speed order (fastest first): registers > cache > RAM > hard disk.

8. Data Units

Computers work in binary — only 0 and 1. One binary digit = 1 bit.
4 bits = 1 nibble | 8 bits = 1 byte | 1024 bytes = 1 KB | 1024 KB = 1 MB | 1024 MB = 1 GB | 1024 GB = 1 TB
Example: decimal 10 = binary 1010; binary 1101 = decimal 13 (8 + 4 + 0 + 1).

9. Generations of Computers

First — vacuum tubes (example: ENIAC, 1946)
Second — transistors
Third — integrated circuits (ICs)
Fourth — microprocessors (VLSI)
Fifth — artificial intelligence (AI), still developing

Mnemonic: "Very Tired Indians Make AI" — Vacuum tube, Transistor, IC, Microprocessor, AI.

Charles Babbage is called the "Father of the Computer" (he designed the Analytical Engine). Ada Lovelace wrote what is regarded as the first computer program. India's first supercomputer, PARAM 8000 (1991), was built by C-DAC, Pune.

10. Abbreviations Exams Ask

HTML — HyperText Markup Language | HTTP — HyperText Transfer Protocol | URL — Uniform Resource Locator
WWW — World Wide Web | LAN / MAN / WAN — Local / Metropolitan / Wide Area Network
USB — Universal Serial Bus | PDF — Portable Document Format | GUI — Graphical User Interface
OS — Operating System | ISP — Internet Service Provider | GPS — Global Positioning System
Email over a network was first sent by Ray Tomlinson (1971), who chose the "@" sign.

🧠 Active Recall: Which memory loses its data when power goes off? Which generation used ICs? (RAM; third.)

Part D — India's Space Programme

11. The Timeline

1962 — INCOSPAR (Indian National Committee for Space Research) set up under the Department of Atomic Energy, with Vikram Sarabhai as its guiding force.
21 November 1963 — first sounding rocket launched from Thumba (TERLS), near Thiruvananthapuram.
August 1969 (15 August) — ISRO (Indian Space Research Organisation) formed in place of INCOSPAR. Headquarters: Bengaluru.
June 1972 — Space Commission and Department of Space (DOS) set up; ISRO came under DOS in September 1972.
19 April 1975 — Aryabhata, India's first satellite, built by ISRO and launched by the Soviet Union.
18 July 1980 — SLV-3, India's first satellite launch vehicle, placed the Rohini satellite in orbit from Sriharikota. Project director: A. P. J. Abdul Kalam.
3 April 1984 — Rakesh Sharma, the first Indian in space, flew on the Soviet Soyuz T-11.

Memory chain: "62 – 63 – 69 – 72 – 75 – 80 – 84" = INCOSPAR – Thumba – ISRO – DOS – Aryabhata – SLV-3 – Rakesh Sharma.

12. Launch Vehicles and Centres

Rockets in order of arrival: SLV → ASLV → PSLV → GSLV → LVM3 (earlier called GSLV Mk III).
PSLV is called ISRO's "workhorse". On 15 February 2017, PSLV-C37 placed 104 satellites in orbit in a single launch.
Satish Dhawan Space Centre (SDSC SHAR) — Sriharikota, Andhra Pradesh: India's spaceport.
Vikram Sarabhai Space Centre (VSSC) — Thiruvananthapuram: rockets.
U R Rao Satellite Centre (URSC) — Bengaluru: satellites.
Space Applications Centre (SAC) — Ahmedabad.
NavIC — India's own regional navigation satellite system.

13. Missions to the Moon, Mars and Sun

Chandrayaan-1 — launched 22 October 2008 by PSLV-C11. India's first Moon mission; found evidence of water molecules on the Moon.
Mars Orbiter Mission (Mangalyaan) — launched 5 November 2013 by PSLV-C25; entered Mars orbit on 24 September 2014. ISRO reached Mars orbit in its very first attempt.
Chandrayaan-2 — launched 22 July 2019 by GSLV Mk III. The orbiter worked, but the Vikram lander crash-landed in September 2019. That spot was later named "Tiranga Point".
Chandrayaan-3 — launched 14 July 2023 by LVM3-M4; Vikram lander soft-landed on 23 August 2023 near the lunar south pole, with the Pragyan rover. India became the fourth country to soft-land on the Moon (after the USSR, USA and China) and the first near the south pole. The landing site is "Shiv Shakti Point", and 23 August is National Space Day.
Aditya-L1 — India's first solar observatory; launched 2 September 2023 by PSLV-C57; placed in a halo orbit around the Sun–Earth Lagrange point L1 on 6 January 2024.

Moon–Mars–Sun order: Chandrayaan-1 (2008) → Mangalyaan (2013) → Chandrayaan-2 (2019) → Chandrayaan-3 (July 2023) → Aditya-L1 (September 2023).

14. Indians in Space and Gaganyaan

Rakesh Sharma (1984) — first Indian citizen in space ("Saare Jahan Se Achha" was his reply when asked how India looked from space).
Kalpana Chawla — first woman of Indian origin in space (1997, Space Shuttle Columbia); she died in the Columbia disaster on 1 February 2003.
Gaganyaan — India's human spaceflight programme. On 27 February 2024 four Indian Air Force test pilots were named astronaut-designates: Prasanth Balakrishnan Nair, Ajit Krishnan, Angad Pratap and Shubhanshu Shukla. Vyommitra is the half-humanoid robot made for uncrewed test flights.

🧠 Active Recall: Arrange: Aryabhata, ISRO formed, SLV-3, Department of Space. (ISRO 1969 → DOS 1972 → Aryabhata 1975 → SLV-3 1980.)

Part E — Nuclear and Defence Milestones

15. Nuclear Programme

1948 — Atomic Energy Commission set up; Homi J. Bhabha its first chairman.
1954 — Department of Atomic Energy; Atomic Energy Establishment, Trombay (AEET) created.
4 August 1956 — Apsara, India's first nuclear research reactor, became operational at Trombay.
22 January 1967 — AEET renamed Bhabha Atomic Research Centre (BARC), Trombay, Mumbai.
1969 — Tarapur (Maharashtra), India's first nuclear power station.
18 May 1974 — Pokhran-I, India's first nuclear test (Rajasthan), code name "Smiling Buddha".
11 and 13 May 1998 — Pokhran-II, five tests, "Operation Shakti". 11 May is National Technology Day.

16. DRDO and Missiles

DRDO (Defence Research and Development Organisation) — formed in 1958; headquarters New Delhi.
Integrated Guided Missile Development Programme (IGMDP) — started in 1983 under Kalam. Its five missiles:
Prithvi — surface-to-surface (short range)
Agni — surface-to-surface ballistic (longer range)
Akash — surface-to-air (medium range)
Trishul — surface-to-air (short range)
Nag — anti-tank guided missile
Mnemonic: "PAATN" — "Papa Aaj Aakash Tak Nache": Prithvi, Agni, Akash, Trishul, Nag.
Other names: BrahMos — supersonic cruise missile, an India–Russia joint venture; name from the Brahmaputra and Moskva rivers. Astra — air-to-air missile.
Tejas — Light Combat Aircraft designed by ADA and built by HAL.
INS Vikrant — India's first indigenous aircraft carrier, built at Cochin Shipyard and commissioned on 2 September 2022.

🧠 Active Recall: Which IGMDP missile is anti-tank, and which two are surface-to-air? (Nag; Akash and Trishul.)

Part F — Institutions and Science Days

17. Scientific Institutions and Their Cities

ISRO — Bengaluru | DRDO — New Delhi | BARC — Trombay, Mumbai | CSIR (1942) — New Delhi
ICMR — New Delhi | ICAR — New Delhi | IARI (Pusa Institute) — New Delhi | IMD (1875) — New Delhi
IISc (1909) — Bengaluru | TIFR (1945) — Mumbai | PRL (1947) — Ahmedabad
C-DAC — Pune | NCL (National Chemical Laboratory) — Pune
CDRI (Central Drug Research Institute) — Lucknow | CCMB (Centre for Cellular and Molecular Biology) — Hyderabad
CFTRI (Central Food Technological Research Institute) — Mysuru | NIO (National Institute of Oceanography) — Goa
NDRI (National Dairy Research Institute) — Karnal | CLRI (Central Leather Research Institute) — Chennai
NPL (National Physical Laboratory) — New Delhi

18. Science Days

28 February — National Science Day (Raman Effect)
11 May — National Technology Day (Pokhran-II, 1998)
23 August — National Space Day (Chandrayaan-3 landing, 2023)
22 December — National Mathematics Day (Ramanujan's birthday)

🧠 Active Recall: Which city has CFTRI, and which has CDRI? (Mysuru; Lucknow.)

Summary Table

⏰ Review this after 2 days.

⚠️ Caution: Examiner's Trap

Trap 1 — "Similar Names": Mendel (heredity, pea plants) vs Mendeleev (periodic table); Salk (injected polio vaccine) vs Sabin (oral polio vaccine); J. J. Thomson (electron) vs William Thomson, Lord Kelvin (temperature scale). Read the full name before choosing.

Trap 2 — "Chronological Confusion": ISRO was formed in 1969, but INCOSPAR came in 1962 and the Department of Space in 1972. Chandrayaan-2 (2019) failed to soft-land; Chandrayaan-3 (2023) succeeded. Aditya-L1 was launched in 2023 but reached its L1 orbit only on 6 January 2024.

Trap 3 — "Almost True Statement": "Aryabhata was launched by an Indian rocket." Ninety per cent true — ISRO built it — but it was launched by the Soviet Union. Similarly, "Light-year measures time" sounds right because of the word "year", but it measures distance.

Trap 4 — "Negative Phrasing": "Which of these is NOT an SI base unit?" — newton, joule, watt and pascal are derived units; only seven are base units.

🔁 Linguistic Bridge: In Hindi we say this, in English we say that

आविष्कार — Invention | खोज — Discovery
मूल मात्रक — Base unit | व्युत्पन्न मात्रक — Derived unit
प्रकाश वर्ष — Light-year | अश्वशक्ति — Horsepower
प्रक्षेपण यान — Launch vehicle | उपग्रह — Satellite
कक्षा (अंतरिक्ष में) — Orbit | चंद्र दक्षिणी ध्रुव — Lunar south pole
परमाणु परीक्षण — Nuclear test | प्रक्षेपास्त्र — Missile
विमानवाहक पोत — Aircraft carrier | स्मृति (कंप्यूटर) — Memory
निवेश / निर्गत युक्ति — Input / Output device

🔗 Static-Dynamic Link

The static ISRO history keeps getting new chapters. Recent dated milestones:
16 January 2025 — SpaDeX (launched 30 December 2024 by PSLV-C60) docked two satellites in space; India became the fourth country to do so, after the USA, Russia and China.
25 June – 15 July 2025 — Group Captain Shubhanshu Shukla flew on the Axiom-4 mission and became the first Indian to visit the International Space Station; the first Indian in space since Rakesh Sharma (1984).
30 July 2025 — NISAR, the first joint Earth-observation satellite of ISRO and NASA, was launched by GSLV-F16 from Sriharikota.
For later launches, check isro.gov.in and pib.gov.in before the exam.

📅 Revision Planner: Three-Level Blurting

🔢 High-Yield Facts & Figures (at a glance)

Science and technology is not a list to fear — it is a story of curious people who kept asking "why?" and "how?". Learn the story, and the facts will stay with you.