Practice question

**Inverse-square law** for charges states F ∝ 1/r² while increasing with charge product. Using k = 9×10⁹ N·m²/C², force at distance r follows F = k q₁q₂/r², forming basis for pairwise force calculation. Electrostatic shielding occurs as free charges in the conductor redistribute to cancel any external field inside. This adjustment creates an induced field that neutralizes the external influence, maintaining zero field within the hollow region. Substituting values gives Electrostatic shielding, which matches expected magnitude for this electrostatic configuration, confirming Coulomb's and Gauss's principles and charge quantization consistency.