Question

Choose the CORRECT statement(s).

• A. The spheroid is a mathematical surface of the Earth.
• B. Geoid is an equipotential reference surface of the Earth.
• C. True shape of the Earth is perfect spheroid.
• D. The WGS-84 datum varies from country to country.

Hint:

The spheroid is a mathematical model used to represent the Earth, and the geoid is the actual shape of the Earth based on gravitational forces.

Answer 1

The Correct Option is A, B

- Option (A): A spheroid is a mathematical model of the Earth. It is a shape that is slightly flattened at the poles and is used as a reference for geographic coordinates. This statement is correct.
- Option (B): The geoid is an equipotential surface of the Earth's gravity field, representing the shape that the Earth's oceans would take under the influence of gravity and rotation, ignoring other influences like winds and tides. This statement is correct.
- Option (C): The true shape of the Earth is not a perfect spheroid but an oblate spheroid, which means it is slightly flattened at the poles and bulging at the equator. Thus, this statement is incorrect.
- Option (D): The WGS-84 (World Geodetic System 1984) datum is a standard reference system used globally and does not vary from country to country. Therefore, this statement is incorrect.
Thus, the correct answers are (A) and (B).