GATE-2018 (24) :Wyllie – Time average equation

35. Statement 1: The Earth's normal spheroid is a mean mathematical surface of the irregular geoid.

Statement2: The normal spheroid lies above the geoid on oceanic and below it under the continents.

 A) Statement 1 and 2 are true               

 B) Statement 1 is true, 2 is false

 C) Statement 1 is false, 2 is true             

 D) Statement 1 and 2 are false

Answer :A

Explanation:

Terminology definitions:

• Reference Ellipsoid: Here, the reference ellipsoid refers to the datum surface derived from the WGS84 reference system.
• Geoid: The gravitational equipotential surface that approximates the global mean sea level, given as the height above the reference ellipsoid.
• Geoid Undulation: Height of the geoid above the reference ellipsoid.
• Geoid Height: Same as geoid undulation.
• Orthometric Height: Height above the geoid.

Reference: Geoid Height Calculator | Software | GAGE (unavco.org)