Practice question

**Fundamental property of charge** includes additivity and quantization, meaning net charge equals algebraic sum of constituents and each is multiple of e. When rod loses charge, electron removal is inferred, and n = q/e gives transferred count. E = (k |q|/r²) . k = 9 × 10⁹ N·m²/C² , q = 12 × 10⁻⁶ C , r = 8 m . E = 9 × 10⁹ × (12 × 10⁻⁶/(8)²) = 9 × 10⁹ × (12 × 10⁻⁶/64) = 1.6875 × 10³ N/C . Substituting values gives 1.69 × 10³ N/C, which matches expected magnitude for this electrostatic configuration, confirming Coulomb's and Gauss's principles and charge quantization consistency.