chegg files are 4-5 and 4-6 for the questions 5-10 and 5-11
4-5 is a sphere of radius a has a charge density that varies with distance r from the center ….
4-6 Two concentric spheres have radii a and b with b>a. The region between them (i. e., a<=r<=b) is filled with charge of constant density. The charge density is zero at everywhere else. Find E at all points and express it in terms of the total charge Q. Do your results reduce to the correct values as a goes to zero?
is the reference text.