Question

What is the equatorial radius of the earth?
A) 6378 Km
B) 6478 Km
C) 6578 Km
D) 6678 Km

Answer 1

Hint: The Earth's equatorial radius a, or semi-major axis, is the separation from its middle to the equator. The equatorial radius is frequently used to contrast Earth and different planets. The Earth can be displayed as a sphere from various perspectives.

Complete answer:
Earth radius is the separation from the focal point of Earth to a point on or close to its surface.
The radius of Earth at the equator is 3,963 miles (6,378 kilometres), as per NASA's Goddard Space Flight Center in Greenbelt, Maryland. However, Earth is not quite a sphere. In any case, Earth isn't exactly a circle. The planet's rotation makes it swell at the equator. Earth's polar radius is 3,950 miles (6,356 km) — a distinction of 13 miles (22 km).

A nominal Earth radius is some of the time utilized as a unit of estimation in space science and geophysics, which is prescribed by the International Astronomical Union to be the tropical worth.
A globally-average value is typically viewed as 6,371 kilometers (3,959 mi) with 0.3% fluctuation (+/ - 10 km) for the accompanying reasons. The International Union of Geodesy and Geophysics (IUGG) gives three references esteems: the mean range (R1) of three radii estimated at two equator focuses and a shaft; the authalic sweep, which is the span of a circle with a similar surface region (R2); and the volumetric span, which is the sweep of a circle having a similar volume as the ellipsoid (R3). Each of the three qualities is around 6,371 kilometres (3,959 mi).

Alternate approaches to characterize and gauge the Earth radius include the range of shape. A couple of definitions yield esteems outside the reach between polar span and the tropical range since they incorporate neighbourhood or geoidal geography or in light of the fact that they rely upon unique mathematical contemplations.

Thus the correct answer is option ‘A’. The equatorial radius of the earth is 6378 Km.

Note: Earth comprises land, air, water and life. The land consists of mountains, valleys and flat areas. The air in Earth’s atmosphere is made up of different gases, mainly nitrogen and oxygen. The watery regions comprise oceans, lakes, rivers, streams, rain, snow and ice.

The interesting features of Earth are:
-Plate tectonics maintains the planet Earth comfortably.
-Earth is considered a sphere.
-Earth is mainly made up of Iron, Oxygen and Silicon.
-70% of the Earth's Surface is under the water.
-The Earth's atmosphere envelops a distance of 10,000 km.
-The Earth's molten iron core forms a magnetic field.