Question map
Not attempted Correct Incorrect ★ Bookmarked
Loading…
Q28 (CDS-I/2009) Geography › Maps & Locations › Geographical lines and coordinates Answer Verified

Which one of the following longitudes determines the Indian Standard Time ?

Result
Your answer: —  Â·  Correct: D
Explanation

Indian Standard Time (IST) is determined by the Standard Meridian of India, which is located at 82°30' E longitude [5]. This longitude is mathematically equivalent to 82.5° E because 30 minutes (30') represent half of a degree (0.5°) [t1]. The meridian passes through Mirzapur in Uttar Pradesh, near Prayagraj [c1][c5]. India adopted this specific longitude to ensure a uniform time across the country, which spans approximately 30 degrees of longitude from west to east [t1][t5]. This choice follows the international convention of selecting standard meridians in multiples of 7°30' [c2]. Consequently, IST is exactly 5 hours and 30 minutes ahead of Greenwich Mean Time (GMT+5:30) [c1][c3]. The meridian also traverses the states of Madhya Pradesh, Chhattisgarh, Odisha, and Andhra Pradesh [t7].

Sources

  1. [2] INDIA PHYSICAL ENVIRONMENT, Geography Class XI (NCERT 2025 ed.) > Chapter 1: India — Location > INDIA – LOCATION > p. 2
  2. [5] https://www.britannica.com/science/Indian-time-zone
How others answered
Each bar shows the % of students who chose that option. Green bar = correct answer, blue outline = your choice.
Community Performance
Out of everyone who attempted this question.
75%
got it right
✓ Thank you! We'll review this.

SIMILAR QUESTIONS

NDA-I · 2012 · Q10 Relevance score: 5.81

The Indian Standard Time (IST) is based on

CDS-I · 2021 · Q58 Relevance score: 4.95

Which one of the following longitudes is the standard meridian of India ?

CDS-II · 2006 · Q89 Relevance score: 4.53

What is the location of measurement of the Indian Standard Time ?

NDA-I · 2008 · Q60 Relevance score: 2.85

Indian Standard Time refers to local time of which one of the following places in India?

CAPF · 2011 · Q32 Relevance score: 1.32

If India adopts two time zones based on 75° E meridian for western India and 90° E meridian for eastern India, which one among the following states of eastern India will be benefited most ?