13- A solid non-conducting sphere of radius 4 cm has a charge of +18 C. A
conducting spherical shell of inner radius 6 cm and outer radius 10 cm is
concentric with the solid sphere and carries a charge of -8.0 C .
a. What is the charge on the inner and the outer surfaces of the shell? (2
points)
b. Find the electric field at:
i. r = 3 cm (4 pts)
ii. r = 5 cm (4 pts)
iii. r = 8 cm (2 pts)
iv. r = 12 cm (4 pts