Inside a hypothetical spherical shell of uniform mass distribution, the gravitational field at any interior point is:
ADirected radially inward
BDirected radially outward
CTangential to the shell
DZero everywhere
Answer & Solution
Correct answer: D. Zero everywhere
1. By the shell theorem (a corollary of the inverse-square law), the contributions of all elements of a uniform shell cancel at every interior point.
2. So the gravitational field inside a uniform shell is identically zero.
3. Outside the shell, the field is the same as if all the mass were concentrated at the centre.
4. This is why g decreases LINEARLY with depth d inside a uniform Earth (only the mass within r = R − d attracts).
_Source: NCERT Class 11 Physics Ch 7 "Gravitation", §7.5–7.6 (shell theorem implication)_
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