49. The shortest land route has to be determined from Mumbai to a city X in Mexico at the same
latitude. The route will be:
(a)A line curving so that it touches higher latitudes
(b)A line curving so that it touches lower latitudes
(c)A line passing through the North Pole
(d)The latitude line connecting Mumbai and X

Shortest Land Route from Mumbai to Mexico on Same Latitude

If you were to determine the shortest land route from Mumbai, India, to a city in Mexico on the same latitude, your first instinct might be to follow the latitude line (a straight east-west line) connecting both cities. However, due to Earth’s spherical shape, this assumption doesn’t hold up. In reality, the shortest route curves northward — a principle that relates to great circle navigation.

Understanding Earth’s Geometry

Earth is not flat; it’s a sphere, and on such a surface, the shortest distance between two points is not a straight horizontal or vertical line — it is a portion of a great circle. A great circle is any circle drawn on a globe (or sphere) that divides the sphere into two equal halves.

• The equator is one example of a great circle.

• Lines of latitude (except the equator) are not great circles; they are smaller circles and do not represent the shortest distance between two points on the same parallel.

Why Not the Latitude Line?

You might assume that following the latitude line — the imaginary horizontal line that marks a constant distance from the equator — is the shortest route. But due to the curvature of the Earth, this route is longer than one that curves slightly northward into higher latitudes.

Correct Answer: (a) A line curving so that it touches higher latitudes

This is because the shortest distance between two points on the globe (such as Mumbai and Mexico at the same latitude) is a curved line, specifically a segment of a great circle, which curves toward the poles (i.e., higher latitudes) for east-west travel between two points not on the equator.

Explanation Through Great Circles

Let’s break it down:

• Mumbai and a Mexican city may be roughly on the same latitude.

• But the great circle connecting them — the shortest route — will curve toward the North Pole.

• This path will look curved on a flat map (like a Mercator projection), but it’s the most direct route on a globe.

This principle is why airplanes flying long international distances often appear to take a longer, curved path on maps — they are actually following the great circle path.

Real-Life Application: Air Travel

Airlines use this concept to:

• Save fuel

• Reduce time

• Minimize costs

For instance, flights from New York to Tokyo often go over Alaska, following a curved great circle path rather than a straight line across the Pacific.

Conclusion

The shortest land or air route from Mumbai to Mexico, even when both cities lie on the same latitude, is not the latitude line itself. Instead, the route curves toward higher latitudes, following a segment of a great circle.

✅ Correct Answer: (a) A line curving so that it touches higher latitudes

This is a classic example of how Earth’s geometry influences navigation, transportation, and geography — proving once again that real-world paths are not always as straight as they seem.