The correct option is (c) 1 and 3 only.
Explanation
To maintain a uniform time system across the vast longitudinal extent of India, a central meridian is selected to determine the time for the entire country. This prevents administrative and logistical confusion arising from local time differences caused by the earth's rotation.
Statement-wise Analysis:
- Statement 1 is Correct: The Standard Meridian of India is situated at 82°30' E longitude. It passes through Mirzapur (near Prayagraj) in Uttar Pradesh and intersects five states: Uttar Pradesh, Madhya Pradesh, Chhattisgarh, Odisha, and Andhra Pradesh.
- Statement 2 is Incorrect: The local time at this meridian is applied as the standard time for the entire country, not just the southern states. This single time zone is adopted to synchronize activities across the nation, despite the approximate two-hour time difference between the westernmost point (Gujarat) and the easternmost point (Arunachal Pradesh).
- Statement 3 is Correct: The time established by the Standard Meridian (82°30' E) is officially designated as the Indian Standard Time (IST). It is 5 hours and 30 minutes ahead of Greenwich Mean Time (GMT).
Key Takeaway:
The 82°30' E longitude serves as the Standard Meridian of India, and its local time is adopted as the Indian Standard Time (IST) for the entire nation to ensure temporal uniformity.