India's Longitudinal Extent Explained

The question asks to identify the correct longitudinal extent of India. The longitudinal extent refers to the difference in longitude between the westernmost and easternmost points of a country or region. It essentially defines how far east-west the territory stretches on the globe.

Understanding Longitude

Longitude lines run vertically from the North Pole to the South Pole. They measure the angular distance, east or west, of any point on the Earth's surface from the Prime Meridian (which is at $0^\circ$ longitude). India lies entirely in the Eastern Hemisphere, meaning all its longitudes are measured east of the Prime Meridian.

India's Geographical Coordinates

Geographically, India's mainland extends between:

• The westernmost longitude: Gujarat, near Dwarka, is at approximately $68^\circ7'E$.
• The easternmost longitude: Arunachal Pradesh, near Kibithu, is at approximately $97^\circ25'E$.

Therefore, the longitudinal extent of India is represented by the range from $68^\circ7'E$ to $97^\circ25'E$.

Significance of Longitudinal Extent

This wide longitudinal spread of about 30 degrees results in a significant difference in local time between the western and eastern parts of India. For example, the sun rises much earlier in Arunachal Pradesh than in Gujarat. To manage this, India follows a standard time based on a meridian that roughly bisects the country, which is the $82^\circ30'E$ longitude (Indian Standard Time - IST).

Evaluating the Options

Based on the established geographical facts:

• Option 1: $68^\circ7'E$ and $97^\circ25'E$. This matches the correct longitudinal extent of India.
• Option 2: $56^\circ7'E$ and $87^\circ25'E$. These values are incorrect.
• Option 3: $58^\circ7'E$ and $94^\circ25'E$. These values are incorrect.
• Option 4: $54^\circ7'E$ and $77^\circ25'E$. These values are incorrect.

Thus, the first option correctly represents the longitudinal extent of India.