You are given a uniformly charged spherical shell that has a radius R and carries a positive charge q. In order to measure the electric field magnitude inside, you drill a small hole that removes 0.01% of the shell’s material and insert a probe into the shell.
1) What is the direction of the electric field at the shell center?
a) Toward the hole.
b) The field is zero.
c) From the hole.
2) What is the approximate magnitude of the electric field at the shell center? Express your answer in terms of the Coulomb’s constant k and some or all of the variables q, R.