Introduction
Science & Tech contributes 4–6 GA marks per SSC Stenographer paper. Questions cover recent ISRO missions, defence technology, basic Physics, Chemistry, Biology and inventions. After this lesson you will own a high-yield checklist that mirrors what SSC repeats year after year.
Core Concept
1. ISRO missions: Chandrayaan-3 (Aug 2023, soft landing on Moon's south pole), Aditya-L1 (Sept 2023 Sun mission), Gaganyaan (upcoming human spaceflight).
2. DRDO: Agni, Prithvi, BrahMos missiles; Tejas LCA.
3. Physics basics: Newton's laws, Ohm's law (V=IR), units (SI: metre, kg, second, ampere).
4. Chemistry basics: Atomic number, valency, common compounds (NaCl, H₂SO₄).
5. Biology basics: Cell organelles, blood groups, vitamins & deficiency diseases (Vit A → night blindness; Vit C → scurvy; Vit D → rickets), human body systems.
6. Inventions: Telephone (Bell), Radio (Marconi), Light bulb (Edison), X-ray (Roentgen), Insulin (Banting & Best).
7. Recent Nobels in Science.
8. IT/AI updates — chatbots, semiconductor missions, India's AI Mission.
Formula Sheet
| Field | Sample fact |
|---|---|
| Space | Chandrayaan-3 landed Aug 23 2023 |
| Vitamin deficiency | Vit C → scurvy |
| Inventions | Telephone — Alexander Graham Bell |
| SI unit | Force — newton (N) |
| Atomic no. of Carbon | 6 |
Solved Examples
Example 1. Which Indian mission landed on Moon's south pole in August 2023?
- Chandrayaan-3.
- Answer: Chandrayaan-3.
Example 2. Vitamin deficiency causes scurvy?
- Vitamin C deficiency.
- Answer: Vitamin C.
Question Patterns
- Mission ↔ year/agency.
- Inventor ↔ invention.
- Vitamin ↔ disease.
- SI unit ↔ quantity.
- Atomic no. ↔ element.
- Recent Nobel laureate.
Mistakes to Avoid
1. Confusing Chandrayaan-2 vs 3.
2. Mixing missiles' ranges.
3. Forgetting deficiency-disease pairs.
4. Skipping current Nobel update.
Exam Importance
| Exam | Frequency | Marks | Notes |
|---|---|---|---|
| SSC Stenographer | High | 4–6 | Space + biology common |
| SSC CGL | High | 5–8 | All clusters |
Why Science & Technology is high-yield. SSC Stenographer 2026 asks 4–6 Science items per paper. The mix is roughly 40% Biology (human physiology, diseases, vitamins, deficiency disorders, plant kingdom), 30% Chemistry (atomic structure, periodic table, chemical bonding, common compounds, daily-life chemistry), 20% Physics (laws of motion, optics, electricity, modern physics, units), and 10% Modern Tech (ISRO missions, defence systems, IT/AI, biotech, space milestones). Memorise the human-body essentials: 206 bones, 22 skull bones, 24 ribs (12 pairs), 33 vertebrae, smallest bone (stapes), longest bone (femur), largest organ (skin), largest gland (liver), pH of blood (7.4), normal BP (120/80), heart rate (72/min). Memorise vitamin-deficiency pairs (A-night blindness, B1-beriberi, B3-pellagra, B12-pernicious anaemia, C-scurvy, D-rickets, K-bleeding). Memorise SI units: force (N), pressure (Pa), energy (J), power (W), frequency (Hz), charge (C), resistance (Ω). Track ISRO missions yearly: Chandrayaan-3 (2023, lunar south pole landing), Aditya-L1 (2023, solar mission), Gaganyaan (in development), Mangalyaan-2 / Shukrayaan / Mars Lander programs.
Quick Revision
- Track ISRO missions every quarter.
- Memorise vitamin-disease pairs.
- Know SI units of common quantities.
- List atomic numbers of first 20 elements.
- Track latest Nobel winners.
- Practise 5 Sci-Tech Qs weekly.
- Cap study time at 60 min.
- Use NCERT class 8–10 for base.
- ISRO launches: Chandrayaan-3 (2023), Aditya-L1 (2023), Gaganyaan test (2023–24), upcoming Mars/Venus orbiters.
- Vitamins: A (retinol/night-blindness), B1 (beriberi), B12 (anaemia), C (scurvy), D (rickets), K (clotting).
- Diseases: malaria (Plasmodium, Anopheles), dengue (Aedes), TB (Mycobacterium), AIDS (HIV).
- Physics laws: Newton's three, Ohm's, Archimedes', Pascal's, Bernoulli's — with one application each.
- Chemistry: pH scale (0–14), states of matter, Mendeleev's periodic table, alloys (brass, bronze, steel).
- Biology: human body systems, blood groups, DNA structure, photosynthesis equation, food-chain levels.
- Human body: 206 bones, 5L blood, 78 organs, 11 systems (digestive/respiratory/circulatory/etc.); largest organ — skin; smallest — pineal gland.
- SI units: metre, kilogram, second, ampere, kelvin, mole, candela; derived units — newton, joule, watt, pascal, hertz.
- Atomic numbers (memorise first 20): H(1), He(2), Li(3), Be(4), B(5), C(6), N(7), O(8), F(9), Ne(10), Na(11), Mg(12), Al(13), Si(14), P(15), S(16), Cl(17), Ar(18), K(19), Ca(20).
- Computer: CPU (brain), RAM (volatile memory), ROM (permanent), 1 byte = 8 bits, 1 KB = 1024 bytes, 1 MB = 1024 KB, 1 GB = 1024 MB.
- Internet: TCP/IP protocol, HTTP/HTTPS, IP address, DNS, URL parts; popular search engines, social-media inventors.
- For SSC Stenographer 2026, expect 1–2 sci-tech items per paper — NCERT-rooted scoring worth 1.5–3 marks.
- India's nuclear establishments: BARC (Mumbai), IGCAR (Kalpakkam), NPCIL (Mumbai), AEC (Mumbai); civil nuclear power plants — Tarapur, Kalpakkam, Kakrapar, Kaiga, Kudankulam.
- India's space launch vehicles: SLV, ASLV, PSLV (workhorse), GSLV, GSLV Mk-III/LVM3 (heavy-lift); upcoming SSLV.
- India's notable scientists: C.V. Raman (Raman effect, Nobel 1930), S. Chandrasekhar (Chandrasekhar limit, Nobel 1983), Har Gobind Khorana (Nobel 1968), Venki Ramakrishnan (Nobel 2009).
- India's biotech and pharma firsts: world's first elephant patient hospital (Mathura), DNA fingerprinting introduced (1988), polio-free certification (2014), COVID vaccine (Covaxin, 2021).