A disk of radius 16 cm has a total charge 4 × 10−6 C distributed uniformly all over the disk. (a) Using the exact formula, what is the electric field 1 mm from the center of the disk? (b) Using the...

A disk of radius 16 cm has a total charge 4 × 10−6 C distributed uniformly all over the disk.

(a) Using the exact formula, what is the electric field 1 mm from the center of the disk?

(b) Using the same exact formula, find the electric field 3 mm from the center of the disk.

(c) What is the percent difference between these two numbers?