Geodesy and Celestial Mechanics

About two-thirds or 71% of the area of the earth is covered by water. Water is present on the earth’s surface in the form of various water bodies like oceans, rivers, seas, canals, lakes, rivers, etc. Major part of the water is present in oceans.

From Earth, we can see about 59% of the Moon's surface due to a phenomenon called libration - the Moon's wobbling motion as it orbits Earth. Although the Moon is tidally locked (one side always faces Earth), librations cause parts of the far side to become visible at different times, allowing us to see slightly more than half.

360° rotation in 24 hours means each hour of Earth's rotation equals 15° of longitude. This 1-hour time difference per 15° is the basis of time zones worldwide.

Indira Point (formerly Pygmalion Point) in Great Nicobar Island is the southernmost point of India's territory, located at approximately 6°45'N to 8°4'N latitude. The question asks for the southernmost latitude, and 8°4'N is the closest representation among the options given. Options B and C showing southern latitude (S) are incorrect as all of India lies in the northern hemisphere.

Perihelion is the point in Earth's orbit where it is closest to the Sun. This occurs annually around January 3-4. The opposite point, when Earth is farthest from the Sun, is called aphelion. The moon, Venus, and Mars are separate celestial bodies, not orbital positions.

The International Date Line generally follows the 180° longitude line, which is the meridian directly opposite the Prime Meridian (0°). This imaginary line in the Pacific Ocean serves as the boundary between one calendar day and the next, with some deviations to accommodate political boundaries of island nations.

The average distance from Earth to the Sun is approximately 150 million kilometers (about 93 million miles). This distance is defined as one Astronomical Unit (AU), which is used as a standard measurement for distances within our solar system.

The Tropic of Cancer (23.5°N latitude) divides India into approximately two halves. It passes through eight Indian states including Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal, Tripura, and Mizoram. This latitude line is a significant geographical marker for India.

India's latitudinal and longitudinal extent is approximately 20°N to 78°E. The country extends from about 8°N to 37°N in latitude and 68°E to 97°E in longitude, with the reference point often cited as 20°N 77°E for the center.

This is the correct matching.

Earth's shape is oblate spheroid.

This is the correct answer. This is the standard meridian of India.

The correct answer is 40075 km because this is the approximate equatorial circumference of Earth. The meridional circumference is slightly less at about 40,008 km. The value 40,075 km represents the standard measurement used in geography and is the distance around Earth at the equator.

A solar day - the time from noon to noon - is exactly 24 hours. While Earth's sidereal rotation (one complete turn relative to stars) is about 23 hours 56 minutes, the 24-hour cycle is what we experience as daylight and darkness. Options A, C, and D are not rotation periods.

A globe is a three-dimensional scale model of Earth and is the most accurate representation of our planet's shape. Maps are flat and distort distances, areas, or shapes. Topography sheets show terrain but not the whole Earth. Only a globe captures the spherical nature.