<s>[INST] I'm curious about the electric field inside a spherical shell of charge. This comes up in a bunch of different scenarios in physics, so I want to make sure I understand it completely. Please explain it to me.
 
The scenario I'm considering is a thin, hollow spherical shell of radius r which has a total charge q distributed evenly over the surface of the sphere. Assume that there is no other charge in the space.
 
The question I'm asking is: what is the magnitude of the electric field at the center of the sphere?[/INST]