In a group discussion on shape and size of the Earth, three students stated the following points :
- 1. Student 1 : The shape of the Earth is basically an oblate spheroid.
- 2. Student 2 : The polar diameter of the Earth is more than the equatorial diameter.
- 3. Student 3 : Bulge along the equatorial region is due to revolution of the Earth.
Who among the above students is/are correct?
Student 1 only
Student 1 and Student 2 only
Student 2 and Student 3 only
Student 1, Student 2 and Student 3
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC NDA-1 – 2022
Student 2: “The polar diameter of the Earth is more than the equatorial diameter.” This is incorrect. The equatorial diameter (approx. 12,756 km) is greater than the polar diameter (approx. 12,714 km) by about 42 km, due to the equatorial bulge.
Student 3: “Bulge along the equatorial region is due to revolution of the Earth.” This is incorrect. The equatorial bulge is primarily caused by the Earth’s *rotation* on its axis. The centrifugal force generated by rotation is strongest at the equator, leading to the outward bulge. Revolution refers to the Earth’s orbit around the Sun.
Therefore, only Student 1’s statement is correct.