Solution to task 322 from Chertov´s for extramural stud

Solution to task 322 from Chertov´s for extramural stud

322. On two concentric spheres of radius R and 2R, charges with surface densities σ1 and σ2 are evenly distributed (Fig. 24). It is required: 1) using the Ostrogradsky-Gauss theorem, find the dependence E (r) of the electric field strength on the distance for three regions: I, II and III. Take σ1 = σ, σ2 = -σ; 2) calculate the strength E at a point remote from the center at a distance r, and indicate the direction of the vector E. Take σ = 0.1 μC / m2, r = 3; 3) build a graph of E (r).