Question

From which of the following longitude the Indian standard time is determined?
A.82.5° E
B.80° West
C.90° East
D.82.30° E

Answer 1

Hint:The time zone that is observed all over India is the Indian standard time. It is commonly denoted as IST. India lies to the north of the equator between north 8°4’ to 37°6’ North latitude and 68°7’ east to 97°25’ east longitude.

Complete answer:
 The 82.5° east longitude is considered as the standard meridian time of India. The distance between the East of India and the west of India is 2933 kilometers. As a result, the sun rises and sets in Arunachal Pradesh in the east two hours earlier than the Rann of Kutch in the west. India does not use the daylight saving technique. This technique was only used during the Indo- China and india-Pakistan war of 1965 and 1971 was briefly used. In the year 1947, the Indian standard time was established. Mirzapur in Allahabad is near to the corresponding longitude reference line, therefore the standard time of India which is calculated on the basis of 82.5° E is calculated from there. The central observatory was shifted to Uttar Pradesh from Chennai. UTC+5:30 is the offset of the Indian standard time which shows that India is 5 hours and 30 minutes ahead of Greenwich meantime.

Hence, the correct answer is option (A).

Note:All the time zones in the world are calculated through Greenwich mean time commonly used as GMT. The Greenwich mean time is measured by the zero degrees line of the meridian of the earth. The zero degree line crosses the north pole to the south pole and passes through the old royal observatory situated in London. Therefore, IST and GMT should not be confused with each other.