Practice question

**Charge conservation and quantization** govern rubbing processes where electrons transfer without creation. Total charge before and after remains equal, and any measured charge corresponds to n = q/e electrons, allowing counting of carriers from coulomb value. E = (2 k λ/r) . 4.5 × 10⁵ = (2 × 9 × 10⁹ × λ/0.04) . λ = (4.5 × 10⁵ × 0.04/18 × 10⁹) = 1 × 10⁻⁶ C/m . Substituting values gives 1.0 × 10⁻⁶ C/m, which matches expected magnitude for this electrostatic configuration, confirming Coulomb's and Gauss's principles and charge quantization consistency.