Why does the electric field near an infinite charged plane not depend on the nature of the material it’s made of?
**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 field depends only on the surface charge density ( sigma/2ε₀ ), as derived from Gauss’s law for an infinite plane. The material affects charge distribution, but for a given sigma , the field is universal, assuming infinite extent and uniformity. Substituting values gives Surface charge density, which matches expected magnitude for this electrostatic
Ref: NCERT > Physics Book > Electric Charges and Fields > Continuous Charge Distribution
