Practice question

**Field intensity** at distance r follows inverse-square law E = (1/4π ε₀)·q/r². At midpoint between two charges, fields superpose vectorially; if charges opposite, fields add in same direction, enhancing magnitude to E = E₁ + E₂. The infinite extent of the plane ensures uniform field distribution, as contributions from all parts balance out distance effects. Gauss’s law confirms the field is sigma/2ε₀ , independent of distance due to symmetry. Substituting values gives Infinite extent, which matches expected magnitude for this electrostatic configuration, confirming Coulomb's and Gauss's principles and charge quantization consistency.