Using the results of Problem 66, we can find the electric field at any radius for any spherically symmetrical charge distribution. A solid sphere of charge of radius R has a total charge of q uniformly spread throughout the sphere.
(a) Find the magnitude of the electric field for r ≥ R.
(b) Find the magnitude of the electric field for r ≤ R.
(c) Sketch a graph of E (r) for 0 ≤ r ≤ 3 R.