Question

图示一厚度为d的无限大均匀带电平板,电荷体密度为P（设原点在带电平板的中央

Answer 1

用高斯定理 ∫ E·dS = q / ε

建坐标,平板中心处x=0

在内部做一个柱面,E ΔS + E ΔS = ρ*2*x*ΔS/ ε,E = ρ*x / ε

在外部做一个柱面,E ΔS + E ΔS = ρ*b*ΔS/ ε,E = ρ*b / (2ε)