Question

Indian Standard Time relates to

• A. 75.5° E longitude
• B. 82.5° E longitude
• C. 90.5° E longitude
• D. 0° longitude

Hint:

82.5° E longitude passes near Allahabad (Prayagraj) and is used for IST.

Answer 1

The Correct Option is B

The question is about determining the longitude that is related to Indian Standard Time (IST). Indian Standard Time is computed from the time at a central meridian that passes through 82.5° E longitude.

Let's understand each of the options:

1. 75.5° E longitude: This is not the reference longitude for IST. It is simply an arbitrary value and does not hold significance for IST.
2. 82.5° E longitude: Correct. Indian Standard Time is based on the time at this longitude which passes through Mirzapur, near Allahabad in Uttar Pradesh. This was chosen to align the time across the Indian subcontinent.
3. 90.5° E longitude: This longitude is too far east and would not correctly represent IST.
4. 0° longitude: This is known as the Prime Meridian and is used as a global reference point. It is not related to the time zone calculations for any specific country like India.

Hence, the correct answer is 82.5° E longitude. This selection ensures a unified and standardized time across India's vast geographical expanse, compensating for the approximate 30° longitudinal difference from India's western to eastern borders.