The Indian Standard Time (IST) is based on
The Indian Standard Time (IST) is based on
- 90° E meridian
- 82½° E meridian
- 75° E meridian
- 0° E meridian
Answer
The earth takes 24 hours to complete one rotation on its axis. The Sun rises first in the east and then in the west because the earth rotates from west to east.
The earth’s longitudinal expanse of 360° is covered in 24 hours, at the pace of 15° per hour (360°/24 = 15°). As the longitudinal extent of India is nearly 29°, the real time difference in India between its eastern and western extremities is roughly of two hours.
To iron out this big chunk of time difference, India, like all other countries of the world, follows the local time of its relatively central meridian as the standard time for the whole country. For the convenience of all, each country chooses its standard meridian in a multiple of 7°30'. Accordingly, the standard meridian of India has been chosen to be 82°30' E.
The correct option is B.