Although the extents of latitude and longitude are same, i.e., 30° why is India’s north-south length longer than the east-west length by 300 km ?
The alignment of the country is such that the north-south length is longer than its east-west length
The north-south length, which is measured along the meridian (great circle) is longer than the east-west length which is measured along the parallel close to the tropic of cancer (small circle)
The north-south and east-west lengths can not be compared, as the former is measured along the meridian and the latter along the parallel
The difference in length is due to variation in scale error along the meridian and parallel
Answer is Wrong!
Answer is Right!
This question was previously asked in
UPSC CAPF – 2010
India’s approximate north-south extent is from about 8°N to 37°N (a difference of 29°), and the east-west extent is from about 68°E to 97°E (a difference of 29°). While the degrees of latitude and longitude are similar, the actual ground distance differs. The north-south distance is measured along meridians, which are effectively great circles, where 1 degree of latitude is approximately constant at 111 km. So, 29° latitude is about 29 * 111 km = ~3200 km. The east-west distance is measured along parallels of latitude. The length of a degree of longitude decreases with increasing latitude. At the Equator, 1 degree of longitude is about 111 km. At the Tropic of Cancer (around 23.5°N), which is close to the center of India’s east-west extent, 1 degree of longitude is significantly less than 111 km (~102 km). Further north, it is even less. Thus, 29 degrees of longitude across India’s width (which is primarily above the equator and around the Tropic of Cancer) covers a shorter distance than 29 degrees of latitude along its length. Option B correctly explains this by stating that the north-south length is measured along meridians (great circles) while the east-west length is measured along parallels (small circles) where the distance per degree of longitude is smaller than per degree of latitude.
The distance covered by a degree of latitude along a meridian is approximately constant, while the distance covered by a degree of longitude along a parallel decreases as latitude increases. India’s east-west extent is across latitudes where the distance per degree longitude is less than at the equator.