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 = (k |q|/r²) . k = 9 × 10⁹ N·m²/C² , q = 10 × 10⁻⁶ C , r = 5 m . E = 9 × 10⁹ × (10 × 10⁻⁶/(5)²) = 9 × 10⁹ × (10 × 10⁻⁶/25) = 3.6 × 10³ N/C . Substituting values gives 3.6 × 10³ N/C, which matches expected magnitude for this electrostatic configuration, confirming Coulomb's and Gauss's principles and charge quantization consistency.