Vision Academy EducareVision Academy Educare
Question 28 of 61 · Physical Features of India
Questioneasy
This question was previously asked in

Railway

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

Answer View answer ▾

Answer: Option A — 5 hours 30 minutes

Detailed Solution

Indian Standard Time is based on the 82.5 degrees East meridian. Since the Earth rotates 1 degree in 4 minutes, 82.5 degrees corresponds to 82.5 x 4 = 330 minutes, which is 5 hours 30 minutes ahead of Greenwich Mean Time (GMT). IST is written as UTC+5:30.

Calculation:

  • Longitude difference from Greenwich (0 degrees) = 82.5 degrees East.
  • Time difference = 82.5 x 4 minutes = 330 minutes = 5 hours 30 minutes.
  • Since the meridian is to the east of Greenwich, IST is ahead of GMT.
  • Example: When it is 12 noon at Greenwich, it is 5:30 pm in India.

GMT and UTC:

GMT is the mean solar time at the Royal Observatory, Greenwich, London, located on the Prime Meridian (0 degrees longitude).

Today, the world's time standard is Coordinated Universal Time (UTC), maintained by atomic clocks. For everyday purposes, UTC and GMT are the same.

Half-hour time zones:

  • Most time zones differ from UTC by whole hours, but India's is a half-hour zone.
  • Other countries with offsets that are not whole hours include Sri Lanka (UTC+5:30), Nepal (UTC+5:45), Afghanistan (UTC+4:30), Iran (UTC+3:30) and Myanmar (UTC+6:30).

Time zones of India's neighbours:

  • Pakistan: UTC+5 (half an hour behind India).
  • Bangladesh and Bhutan: UTC+6 (half an hour ahead of India).
  • China: UTC+8, a single time zone for the whole country.

India's time-keeping:

  • The CSIR-National Physical Laboratory (NPL), New Delhi, maintains IST.
  • India does not observe daylight saving time.

Why not the other options?

  • ✗4 hours 30 minutes is Afghanistan's offset.
  • ✗5 hours is Pakistan's offset.
  • ✗6 hours 30 minutes is Myanmar's offset.

Quick tip

Remember: IST = GMT + 5 hours 30 minutes (82.5 degrees East x 4 minutes = 330 minutes).

💬 Discussions on this question

Ask a doubt ›

Still stuck on this question? Ask our faculty and fellow students — answers appear here.

Ask a doubt

More Physical Features of India Questions

View all ›
  1. Q1.Which is the largest state of India by area?
  2. Q2.The stretch of the western coast of India between Mumbai and Goa is known as the:
  3. Q3.The Eastern Ghats stretch from the:
  4. Q4.In India, 'Kayals', a distinctive feature of the Malabar Coast, refer to:
  5. Q5.India's share of the world's total land area is about:

More General Knowledge Questions

  1. Q1.The techniques of Rasa and Bhava used in Indian classical dance trace their origin to which ancient text?Indian Dance Forms
  2. Q2.Lavani, Powada, Koli, Waghya Murali and Dhangari Gaja are folk dances of which state?Indian Dance Forms
  3. Q3.The one-act play associated with the Sattriya tradition of Assam is called:Indian Dance Forms
  4. Q4.Which dance form of Goa is known as the 'Warrior Dance'?Indian Dance Forms
  5. Q5.Manipuri dance is based on the Rasleela themes of:Indian Dance Forms

Physical Features of India — Preparation

This question tests your understanding of Physical Features of India, a key topic in the General Knowledge section. The detailed solution above uses a step-by-step approach to show the reasoning, and where available, a shortcut that helps you solve similar questions in under 90 seconds during the actual exam.

This topic covers India's location and extent, its neighbours and boundary lines, and its physiographic divisions: the Himalayas, the Northern Plains, the Peninsular Plateau, the Indian Desert, the coastal plains and the islands, along with important mountain passes, peaks and hill ranges. Questions often ask which states the Tropic of Cancer passes through, the southernmost point of India (Indira Point), the highest peak in India (Kangchenjunga), and which pass connects which regions. India shares its longest land border with Bangladesh. Learning the Himalayan ranges from north to south (Himadri, Himachal and Shiwaliks) is also useful. Practise the physical features of India questions below, written in the style of the general awareness sections of exams such as SSC, banking, railways, CUET GAT, MAH CET and CLAT. Each question comes with a detailed explanation that adds related facts, so every question helps you revise more than one point.

‹ All Physical Features of India questionsBrowse all topics ›