Question

o 3-16 Problems: 3.20 Charge is uniformly distributed over the surface of a very long cylinder of radius b. Compute the electric field intensity everywhere. How much flux is passing through a window at ρ-c(c > b), 0 φ π/2 , and 0 z h?

Answer 1

Let total charge on rho = b cylindrical surface for h height is + Q then rho_s = Q/2 pi b h Q = rho_s (2 pi bh) E vector in the region 0 < rho < b where rho_s is surface charge density D middot dS = Q_enc D_rho (2 pi rho h) = 0 D_rho = 0 D vector = D_rho a_rho = 0 E vector = D vector/E = 0 \r\n E in the region b < rho < infinity D middot dS = Q_enc D_rho (2 pi rho h) = Q D_rho = Q/2 pi rho h D_rho = rho_s (2 pi b h)/2 pi rho h = rho_s b/rho D vector = D_rho a_rho = rho_s b/rho a_rho^^E = E vector/E = rho_s b/rho E = rho_s b/rho E a_rho^^= rho_s b/rho E_0 a_rho^^E = {0 rho_s b/rho E_0 p < b b < rho < infinity rho = C (c > b)