Science and Technology
Overview
Science and Technology is a dynamic section in APPSC Group II Prelims that tests your awareness of India's scientific achievements, emerging technologies, and their applications. This topic carries significant weightage and questions often come from recent developments in space missions, defence systems, IT initiatives, and environmental technologies.
The key to mastering this section is understanding fundamental scientific concepts while staying updated on India's flagship programs like ISRO missions, DRDO developments, and Digital India initiatives. Questions typically test factual knowledge—who developed what, when was it launched, what is its application—rather than deep technical understanding. A strategic approach combines learning core scientific principles with regular current affairs reading focused on S&T developments.
Key Concepts
- ISRO's Launch Vehicles: PSLV (workhorse for satellites, sun-synchronous orbits), GSLV (heavier payloads, geosynchronous orbits), and LVM3 (formerly GSLV Mk III, for Chandrayaan and Gaganyaan missions). PSLV has over 50 successful launches.
- Satellite Categories by Purpose: Communication satellites (INSAT, GSAT series), Remote sensing (IRS series, Cartosat), Navigation (NavIC/IRNSS—Indian regional system covering 1,500 km beyond borders), and Scientific satellites (AstroSat for astronomy).
- Nuclear Triad: India's three-pronged nuclear delivery capability—land-based missiles (Agni series), air-delivered bombs (Mirage 2000, Sukhoi), and submarine-launched missiles (K-15 Sagarika from INS Arihant).
- Biotechnology Applications: Bt Cotton (Bacillus thuringiensis gene for pest resistance—only GM crop approved for commercial cultivation in India), recombinant DNA technology for insulin, and indigenous COVID-19 vaccines (Covaxin by Bharat Biotech).
- Digital India Pillars: Digital infrastructure (BharatNet for rural broadband), e-governance (DigiLocker, UMANG app), and digital empowerment (digital literacy programs).
- Renewable Energy Mix: Solar (National Solar Mission target), wind power (Tamil Nadu, Gujarat leading states), and India's commitment to 50% non-fossil fuel energy capacity by 2030.
- Missile Classification by Range: Short-range (<1000 km: Prithvi), Medium-range (1000-3500 km: Agni-1, 2), Intermediate-range (3500-5500 km: Agni-3, 4), and ICBM (>5500 km: Agni-5).
Formulas / Key Facts
| Category | Key Facts |
|---|---|
| Space | Chandrayaan-3 (2023): Soft landing at lunar south pole; Vikram lander + Pragyan rover. India became 4th country to achieve soft landing. |
| Space | Gaganyaan: India's first crewed spaceflight program; targets 3 astronauts to 400 km orbit for 3 days. |
| Space | Aditya-L1: India's first solar observatory mission; positioned at Lagrange Point 1 (L1), 1.5 million km from Earth. |
| Defence | BrahMos: World's fastest cruise missile (Mach 2.8-3); Indo-Russian joint venture; range ~500 km. |
| Defence | Tejas: Indigenous Light Combat Aircraft; developed by HAL and DRDO/ADA. |
| Defence | INS Vikrant: India's first indigenously built aircraft carrier; commissioned 2022. |
| IT | UPI (Unified Payments Interface): Real-time payment system by NPCI; India leads globally in digital transactions. |
| IT | Aadhaar: 12-digit unique ID by UIDAI; biometric + demographic data; world's largest biometric system. |
| Environment | Hydrogen Mission: Green hydrogen from electrolysis using renewable energy; part of decarbonization strategy. |
| Nuclear | India operates PHWRs (Pressurized Heavy Water Reactors) and has thorium-based advanced reactor program. |
Worked Examples
Example 1: Satellite Orbit Identification
Question: A satellite is placed at 35,786 km above Earth's equator and appears stationary relative to Earth. What type of orbit is this?
Solution:
- Step 1: Identify key features—very high altitude (about 36,000 km), equatorial position, appears stationary
- Step 2: A satellite that appears stationary matches Earth's rotational period (24 hours)
- Step 3: This is a Geostationary Orbit (GEO)
- Application: Used for communication satellites (INSAT series) and weather observation
- Answer: Geostationary Orbit
Example 2: Missile System Classification
Question: Agni-4 has a range of approximately 4,000 km. Under which category of ballistic missiles does it fall?
Solution:
- Step 1: Recall range classifications—SRBM (<1000), MRBM (1000-3500), IRBM (3500-5500), ICBM (>5500)
- Step 2: 4,000 km falls between 3,500 and 5,500 km
- Answer: Intermediate Range Ballistic Missile (IRBM)
Example 3: Biotechnology Application
Question: Which organism's gene is inserted in Bt Cotton to provide pest resistance?
Solution:
- "Bt" stands for Bacillus thuringiensis, a soil bacterium
- The Cry gene from this bacterium produces proteins toxic to bollworm larvae
- Answer: Bacillus thuringiensis (a bacterium)
Common Mistakes
- Confusing PSLV and GSLV capabilities → PSLV is for lighter satellites to lower/polar orbits; GSLV/LVM3 handles heavier payloads to higher geosynchronous orbits. Remember: PSLV = Polar, lighter; GSLV = Geo, heavier.
- Mixing up NavIC with GPS → NavIC (Navigation with Indian Constellation) is India's regional system with 7 satellites covering India and 1,500 km beyond. GPS is American and global. NavIC uses both L5 and S bands.
- Assuming all nuclear reactors use uranium → India's three-stage nuclear program specifically aims to utilize thorium reserves (world's largest in India). Stage 3 involves thorium-based reactors.
- Confusing Chandrayaan missions → Chandrayaan-1 (2008): Orbiter + Moon Impact Probe; Chandrayaan-2 (2019): Orbiter successful, lander crashed; Chandrayaan-3 (2023): Successful soft landing, no orbiter (used Chandrayaan-2's orbiter).
- Thinking BrahMos is fully indigenous → BrahMos is a joint Indo-Russian venture (BrahMaPutra + Moskva rivers). Truly indigenous missiles include Prithvi and Agni series developed by DRDO.
Quick Reference
- ISRO Headquarters: Bengaluru; Chairman as of 2024: S. Somanath
- DRDO: 52+ labs; HQ New Delhi; develops Agni, Prithvi, Tejas, Arjun tank
- NavIC: 7 satellites (3 GEO + 4 GSO); regional coverage; dual frequency
- India's first nuclear test: Pokhran-I (Smiling Buddha) 1974; Pokhran-II 1998
- Supercomputers: PARAM series by C-DAC; latest PARAM Siddhi among top global systems
- Gaganyaan astronauts: Called "Vyomanauts" (Vyoma = space in Sanskrit)