Practice question

**Line charge concept** extends point charge to infinite wire where symmetry dictates radial field proportional to λ and inversely proportional to distance r. λ = q/L for uniform case, field direction depends on sign of λ, outward for positive. The surface charge density on the sheet generates a field that changes abruptly. Gauss’s law shows the field on either side is sigma/2ε₀ , with opposite directions, resulting in a discontinuity equal to sigma/ε₀ across the surface. Substituting values gives Surface charge density, which matches expected magnitude for this electrostatic configuration, confirming Coulomb's and Gauss's principles and charge quantization consistency.