Why is 82030’ E taken as the Indian Standard Time?
1. The earth rotates on its axis in 24 hours.
2. I this time it covers 3600.
3. Each degree of longitude covers 4 minutes.
4. The central Meridian 82030’ When multiplied by 4 minutes it comes to 330 minutes or 5 hours and 30 minutes.
5. So IST= GMT+51/2 hours. Greenwich Mean Time refers to 00 longitudes.
