What is the key assumption about Earth’s density in calculating g below its surface?
Considering the Earth has uniform density to simplify the mass contributing to gravity inside (Mr = MEr3RE3), leading to g(d) = g(1−d/RE). Non-uniform density would complicate this. As per NCERT, applying relevant law/formula with correct units and sign convention leads to It is uniform. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.