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. Distance from +3 μC = 5 cm. E₁ = 9 × 10⁹ × (2 × 10⁻⁶/(0.05)²) = 7.2 × 10⁶ N/C (away). E₂ = 9 × 10⁹ × (3 × 10⁻⁶/(0.05)²) = 1.08 × 10⁷ N/C (towards). Net E = 1.08 × 10⁷ - 7.2 × 10⁶ = 3.6 × 10⁶ N/C (towards +3 μC ). Substituting values gives 3.6 × 10⁶ N/C, which matches expected magnitude for this