The acceleration due to gravity at the Earth's surface, g, is related to its mass M and radius R by:
Ag = G M / R
Bg = G M² / R²
Cg = G M / R²
Dg = G M / R³
Answer & Solution
Correct answer: C. g = G M / R²
1. Gravitational force on a mass m at the surface: F = G M m / R².
2. By Newton's second law, F = m g, so g = F / m = G M / R².
3. This expression assumes a spherical, uniform-density Earth and ignores rotation.
_Source: NCERT Class 11 Physics Ch 7 "Gravitation", §7.5 Acceleration due to Gravity, p. 132_
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