UPSC CSE Science and Technology Syllabus

Science and Technology syllabus — full chapter and topic list

Expand any chapter to see its topics and sub-topics. This is the whole examinable outline for Science and Technology in UPSC CSE, not a summary of it.

1. 1

   Basics of Science and Technology

   3 topics

   • Space Technology
   • Nanotechnology
   • Biotechnology
2. 2

   Energy

   3 topics

   • Renewable Energy
   • Nuclear Energy
   • Energy Conservation
3. 3

   Computer and IT

   3 topics

   • Internet and its Applications
   • Telecommunication
   • Cyber Security

Science and Technology flashcards for UPSC CSE

24 of 56 cards from the Science and Technology deck — real questions with worked answers.

1. What is the escape velocity from Earth's surface, and why is it significant for space launches?

   Approximately 11.2 km/s. A body must reach this speed to break free of Earth's gravity without further propulsion; rockets must impart at least this much energy to send a payload into deep space.

2. Differentiate between a GEO (Geostationary) and a LEO (Low Earth Orbit) satellite by altitude and use.

   GEO: ~35,786 km altitude, orbital period 24 hrs so it appears fixed over one point (used for communication, broadcasting, weather). LEO: 160-2,000 km, short period, used for Earth observation, remote sensing, and constellations like Starlink.

3. What are the three Cosmic Velocities used in astronautics?

   First cosmic velocity (~7.9 km/s) = orbital velocity for a circular LEO; Second cosmic velocity (~11.2 km/s) = escape velocity from Earth; Third cosmic velocity (~16.7 km/s) = velocity to escape the Solar System from Earth's orbit.

4. Name India's two main satellite launch vehicles and the payload class each serves.

   PSLV (Polar Satellite Launch Vehicle) - reliable workhorse for light/medium satellites to polar/sun-synchronous orbits; GSLV (Geosynchronous Satellite Launch Vehicle), including GSLV Mk III/LVM3, for heavier communication satellites to GTO.

5. What is a Sun-Synchronous Orbit and why is it used for remote sensing?

   A near-polar orbit (~600-800 km) whose plane precesses to keep a constant angle with the Sun, so the satellite passes over a given latitude at the same local solar time each day, giving consistent illumination for imaging.

6. What is NavIC and how many satellites does its constellation use?

   NavIC (Navigation with Indian Constellation), formerly IRNSS, is India's regional satellite navigation system using a constellation of 7 satellites (3 geostationary + 4 geosynchronous).

7. What is a geosynchronous transfer orbit (GTO)?

   An elliptical orbit with perigee in LEO and apogee at geostationary altitude (~35,786 km), used as an intermediate orbit; the satellite's onboard engine then circularizes it into a geostationary orbit.

8. What is nanotechnology, and what is the size range of a nanometre?

   Nanotechnology is the manipulation of matter at the nanoscale (roughly 1-100 nanometres). One nanometre = 1 x 10^-9 metre, about 1/80,000th the width of a human hair.

9. Distinguish the 'top-down' and 'bottom-up' approaches in nanofabrication.

   Top-down: carving nanostructures from bulk material by etching/lithography (e.g., chip manufacturing). Bottom-up: building structures atom-by-atom or molecule-by-molecule via self-assembly/chemical synthesis (e.g., growing nanotubes).

10. What are carbon nanotubes and one notable mechanical property?

    Cylindrical structures of rolled-up graphene sheets (single- or multi-walled). They have an exceptionally high tensile strength (about 100 times that of steel at one-sixth the weight) and high electrical/thermal conductivity.

11. What is graphene and how is it structured?

    A single two-dimensional layer of carbon atoms arranged in a hexagonal (honeycomb) lattice. It is the thinnest known material, extremely strong, transparent, and an excellent electrical conductor.

12. Why do nanomaterials often show different properties than their bulk form?

    At the nanoscale the surface-area-to-volume ratio is very high and quantum effects become significant, altering optical, electrical, magnetic, and chemical reactivity properties compared with bulk material.

13. What are quantum dots and one key application?

    Quantum dots are semiconductor nanocrystals whose optical/electronic properties depend on their size (quantum confinement). They emit specific colors of light and are used in displays (QLED TVs), solar cells, and biomedical imaging.

14. What is biotechnology?

    The use of living organisms, cells, or their biological systems and processes to develop or make products and technologies useful to humans (e.g., in medicine, agriculture, and industry).

15. What does PCR stand for and what is its purpose?

    Polymerase Chain Reaction - a laboratory technique to amplify (make millions of copies of) a specific DNA segment, used in diagnostics, forensics, and research.

16. What is CRISPR-Cas9 used for in biotechnology?

    It is a precise gene-editing tool that uses a guide RNA and the Cas9 enzyme to cut DNA at a target location, allowing scientists to delete, insert, or modify specific genes.

17. What is a Genetically Modified Organism (GMO)? Give an Indian example.

    An organism whose genetic material has been altered using genetic engineering. Indian example: Bt cotton, which carries a Bacillus thuringiensis gene producing a protein toxic to bollworm pests.

18. What is recombinant DNA technology?

    A technique that combines DNA from different sources (often using restriction enzymes and ligases) to create new genetic combinations, e.g., inserting the human insulin gene into bacteria to mass-produce insulin.

19. Differentiate gene therapy from genetic engineering.

    Gene therapy treats or prevents disease by introducing, removing, or correcting genes within a patient's cells. Genetic engineering is the broader manipulation of an organism's genes for any purpose, including producing GMOs.

20. What are stem cells and what makes them unique?

    Undifferentiated cells capable of self-renewal and of differentiating into specialized cell types. Embryonic stem cells are pluripotent (can form any cell type); adult/induced pluripotent stem cells (iPSCs) are used in regenerative medicine.

21. What is the difference between renewable and non-renewable energy sources?

    Renewable sources replenish naturally on a human timescale (solar, wind, hydro, biomass, geothermal). Non-renewable sources are finite and deplete with use (coal, oil, natural gas, nuclear fuels).

22. What is the photovoltaic effect that solar cells rely on?

    The generation of voltage and electric current in a material (typically silicon) upon exposure to light, as photons knock electrons loose to create a flow of current across a p-n junction.

23. Name the main types of renewable energy and their primary source.

    Solar (sunlight), Wind (moving air), Hydropower (flowing water), Biomass/Biofuel (organic matter), Geothermal (Earth's internal heat), and Tidal/Wave (ocean movement).

24. How does a wind turbine generate electricity?

    Wind turns the turbine's blades (rotor), converting kinetic energy into rotational mechanical energy; this drives a generator that converts mechanical energy into electrical energy via electromagnetic induction.

See more Science and Technology flashcards →

Planning Science and Technology for UPSC CSE

Science and Technology (UPSC CSE) FAQ