Question

how is standard meridian of india calculated?

Answer 1

To find the time meridian of a country, take the westernmost longitude and the easternmost longitude of that country, take the mean, and find the nearest multiple of 7.5 degree. As India's longitudinal extent is from 68° 7' 53" E to 97° 24' 47" E. The mean comes out to be 82°46'20".

Answer 2

According to international convention the longitudinal difference between two time meridians should be a multiple of 7.5 degrees, so that time difference is always in half hours or full hours (7.5 deg * 4 min/deg = 30 minutes).

To find the time meridian of a country, take the westernmost longitude and the easternmost longitude of that country, take the mean, and find the nearest multiple of 7.5 degree.

As India's longitudinal extent is from 68° 7' 53" E to 97° 24' 47" E.

Nearest multiple of 7.5° is 82.5°.

So 82"30 minutes east has been selected as the Standard Meridian Time of India

Hope u understood