Telangana PSC – General Awareness & Current Affairs
World Geography – Advanced University‑Level Study Notes
Audience: Telangana PSC aspirants, but the notes are written at a MIT‑level depth to give you a solid, research‑grade understanding of world geography.
| Section | What you’ll learn | Why it matters for PSC |
|---|---|---|
| 1. Earth’s Physiology | Shape, size, and the mathematics behind the geoid | Accurate knowledge of latitude/longitude, time zones, and mapping is crucial for many PSC questions. |
| 2. Coordinate Systems & Projections | From spherical trigonometry to UTM & MGRS | Many questions ask for conversions or location identification. |
| 3. Surface Features | Continents, oceans, tectonics, landforms | Fundamental for “Maps & Regions” and “Physical Geography” sections. |
| 4. Climate & Biomes | Köppen classification, edge‑case climates | Climate‑related questions often appear in Current Affairs. |
| 5. Political & Economic Geography | Sovereign states, micro‑states, enclaves, disputed territories | PSC tests often ask about new countries, boundary disputes, and economic hubs. |
| 6. GIS & Remote Sensing | Data types, sensors, applications | Emerging technology questions; also helps in interpreting satellite maps. |
| 7. Edge Cases & Anomalies | International waters, Antarctica, unrecognized states | Know the “exceptional” places that can be trick questions. |
| 8. Current Affairs (2024‑2026) | New countries, territorial changes, climate‑related geography | Keep the dates and facts fresh. |
| 9. Challenging Problem | A real‑world geographic calculation | Tests your ability to apply theory. |
Tip: While the notes are dense, the key for PSC is to extract the most exam‑relevant facts and practice converting them into quick, reliable answers.
1. Earth’s Physiology – From First Principles
1.1. The Shape of the Earth
| Feature | Symbol | Approx. Value |
|---|---|---|
| Equatorial radius | (a) | (6,378,137) m (WGS‑84) |
| Polar radius | (b) | (6,356,752) m |
| Flattening | (f) | (\frac{a-b}{a} \approx 1/298.257223563) |
| Mean radius | (R) | (6,371,009) m |
Why not a perfect sphere?
The Earth is a rotating, fluid‑like body; rotation causes centrifugal force that bulges the equator. The resulting shape is an oblate spheroid (ellipsoid).
Mathematical representation
[
\frac{x^2 + y^2}{a^2} + \frac{z^2}{b^2} = 1
]
1.2. The Geoid
- Definition: The equipotential surface that best matches mean sea level everywhere.
- Mathematical form: (V(x, y, z) = \text{constant}), where (V) is the geopotential.
- Undulation (N): Difference between ellipsoid and geoid:
[ N = h - H ] where (h) = ellipsoidal height, (H) = orthometric height.
Why PSC‑relevant?
- Many questions involve altitude or sea‑level rise and require understanding that GPS gives ellipsoidal heights, while altimeters report orthometric heights.
2. Geographic Coordinate Systems & Projections
2.1. Latitude & Longitude
| Parameter | Symbol | Range | Meaning |
|---|---|---|---|
| Latitude | (\phi) | (-90°) to |