Geodesy and Celestial Mechanics

Pole star is situated in the direction of the earth's axis. Due to this, it does not appear to move.

Correct option. Geoid means Earth like shape, slightly flattened at the poles.

Earth's mean radius is approximately 6,371 kilometers (about 3,959 miles). This value represents the average distance from Earth's center to its surface. The other options are either too small (like 1,290 km, which is closer to the Moon's radius) or don't match the accepted scientific value.

Yes, it is correct.

Earth's circumference at the equator is approximately 40,075 km. With 360 degrees of longitude, each degree spans about 111.3 km at the equator (40,075 / 360 = 111.3 km). This is a standard geographical fact and an important value for understanding the scale of Earth's coordinate system. The distance between meridians decreases as you move toward the poles due to the convergence of longitude lines.

Proxima Centauri is the closest known star to the Sun and part of the Alpha Centauri star system. It is located approximately 4.24 light-years away from Earth, making it the nearest stellar neighbor to our solar system.

India's Standard Meridian is 82° 30' E, passing through Mirzapur (Uttar Pradesh). This longitude was chosen to balance the time difference between eastern and western India, giving a single time zone (IST) for the entire country.

She went 360 km away from the earth.

We can see the curved shape of the earth. We cannot recognise lines on the earth like in the map.

This option is correct because;  , λ = h / mv . and from conservation of angular momentum we have = mvr = nh / 2π . => 2πr = nλ . in this case value of n is 4 . hence, this option is correct.

Earth takes 365 rotations on its axis when it moves around the Sun once. Earth completes its one revolution around the sun in 365 days, i.e,  a Year. It takes 23 hours, 59 minutes and 4 seconds for the Earth to make one complete rotation on its axis.

The percentage of land surface in the Northern Hemisphere is the maximum between 40⁰ and 50⁰ latitude.

Magnetic north pole of earth will be found in gemetrical south pole direction.

The Earth's equatorial radius is approximately 6,378 km, which is roughly 6,000 km. This is the distance from Earth's center to the equator. The polar radius is slightly smaller at about 6,357 km, giving Earth its slightly flattened shape.

Earth's rotational speed is highest at the Equator because the circumference is greatest there (approximately 40,075 km). Since Earth completes one full rotation in 24 hours everywhere, points on the Equator must travel the longest distance in the same time, resulting in the highest linear speed (about 1,670 km/h). At the poles, rotational speed approaches zero.