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RAS question

Indian Standard Time (IST) is ahead of Greenwich Mean Time (GMT) by:

Correct answer: (C) 5 hours 30 minutes.

Indian Standard Time is 5 hours 30 minutes ahead of Greenwich Mean Time.

  1. (A)

    4 hours 30 minutes

  2. (B)

    5 hours

  3. (C)

    5 hours 30 minutes

  4. (D)

    6 hours

Explanation

IST is UTC+5:30, so it is 5 hours 30 minutes ahead of GMT. The official time authority, CSIR-NPL, explains that it maintains Indian Standard Time and generates IST as UTC(NPLI) plus 5:30 hours. In geography terms, this offset is linked to the 82.5 degrees E standard meridian passing through Mirzapur, near Allahabad, in Uttar Pradesh. Although India extends across about 30 degrees of longitude, it follows one national standard time instead of multiple time zones. The half-hour offset after five hours aligns with both the official IST definition and the standard-meridian basis of Indian time.

Why the other options are wrong

  • (A) 4 hours 30 minutes is one hour short of the official IST offset of UTC plus 5:30 hours.
  • (B) 5 hours would correspond to a 75 degrees E meridian, whereas IST is linked to the 82.5 degrees E standard meridian.
  • (D) 6 hours is 30 minutes more than the official IST offset stated by CSIR-NPL as UTC(NPLI) plus 5:30 hours.

Concept

The standard-meridian and time-zone concept is a core part of Indian geography. Longitude, local time and India's single standard time are basic map-reading and location fundamentals in RAS preparation.

Source

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