๐ Topic 02 of 6 ยท Chapter 11 ยท World Physical Geography
Latitude, Longitude & Time Zones
Important latitudes, IST, International Date Line, GMT โ complete notes for UPSC & PSC exams.
๐ Important Latitudes
| Line | Degree | Significance |
|---|---|---|
| Equator | 0ยฐ | Divides Earth into N & S hemispheres; longest circle; equal day & night throughout year |
| Tropic of Cancer | 23.5ยฐN | Northernmost point of Sun’s overhead position (June 21); passes through 8 Indian states |
| Tropic of Capricorn | 23.5ยฐS | Southernmost point of Sun’s overhead position (Dec 22) |
| Arctic Circle | 66.5ยฐN | Midnight Sun; polar day/night; 6 months day, 6 months night at poles |
| Antarctic Circle | 66.5ยฐS | Surrounds Antarctica; similar polar phenomena |
๐ Important Longitudes
| Line | Degree | Significance |
|---|---|---|
| Prime Meridian (Greenwich) | 0ยฐ | Passes through Greenwich, UK; basis of GMT (Greenwich Mean Time) |
| International Date Line (IDL) | 180ยฐ | Opposite of Prime Meridian; date changes when crossed; zigzags to avoid dividing countries |
| India Standard Time (IST) | 82.5ยฐE | Passes through Mirzapur (UP); IST = GMT + 5:30 hours |
โญ Tropic of Cancer passes through India:
Gujarat โ Rajasthan โ MP โ Chhattisgarh โ Jharkhand โ West Bengal โ Tripura โ Mizoram (8 states)
Memory: Good Road Makes Cars Jump Well Today Morning
Gujarat โ Rajasthan โ MP โ Chhattisgarh โ Jharkhand โ West Bengal โ Tripura โ Mizoram (8 states)
Memory: Good Road Makes Cars Jump Well Today Morning
๐ IST Calculation:
82.5ยฐE ร 4 minutes/degree = 330 minutes = 5 hours 30 minutes ahead of GMT
India has a single time zone despite spanning ~29ยฐ of longitude (east-west)
Sun rises ~2 hours earlier in Arunachal Pradesh than in Gujarat
82.5ยฐE ร 4 minutes/degree = 330 minutes = 5 hours 30 minutes ahead of GMT
India has a single time zone despite spanning ~29ยฐ of longitude (east-west)
Sun rises ~2 hours earlier in Arunachal Pradesh than in Gujarat