1。 ( 1)E = 0； ; (2) The electric field intensity at a distance of 0. 1m from the thin layer surface.

e=ρd/2ε0=( 10^(-4)*0.3* 10^(-2)/2*8.85* 10(- 12)= 1.695* 10^(-4)v/m

3) The electric field intensity outside the thin layer e = ρ d'/2ε 0 = (10 (-4) * 0.5 *10 (-2)/2 * 8.85 *10 (-12) = 2.

2。 v = q/4ωω0R = = & gt； q=4πε0r/v=4*3. 14*8.85* 10(- 12)*2* 10^(-3)/300=7.4 14* 10^(-8)c

v ' = 2q/4ωε0R ' = 476.22vεσρ

3.( 1)v=σ/2ε0((r^2+x^2)^( 1/2)-x)

(2)e=-dv/dx=σ/2ε0( 1-x/(r^2+x^2)^( 1/2))

(3)x=6cm,V=4.52* 10^(4)V

E=4.52* 10^(5)V/m