Official Answer Key & Detailed Solution
Ready to check the official UPSC Answer Key?
Click any option above to test yourself under exam conditions, or reveal the explanation directly.
Correct Answer: Option (B) — 10.38 a.m.
Concept & Option Breakdown
Standard Reference Verified- Indian Standard Time (IST) is based on the standard meridian of 82.5° E longitude.
- Shillong is located at 92° E longitude.
- Difference in longitude = 92° - 82.5° = 9.5°.
- Time difference = 9.5° × 4 minutes/degree = 38 minutes.
- Since Shillong lies to the east of 82.5° E, its local time is ahead of IST.
- Local time = 10:00 AM + 38 minutes = 10:38 AM.
1° longitude = 4 minutes. East of the meridian means adding time. 9.5° × 4 min = +38 minutes, giving 10:38 AM.
Practice Full-Length & Sectional Prelims Mocks on this Interface
50 simulated tests in the APT Prelims Test Series (₹1,493) or 1-on-1 Mentorship with Avinash Sir.