31. Ebony solid ball of radius R = 5 cm carries a charge that is uniformly distributed over the volume of bulk density ρ = 10 nC / m3. Determine the intensity E of electric field displacement D at the points of: r1 = distance of 3 cm from the center of the sphere; 2) on the surface of the ball; 3) at a distance r2 = 10 cm from the center of the ball. Plotted as E (r) and D (r).

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)