# Electric field of a sphere

1. Mar 9, 2014

### cooper607

hi guys, i have been following griffith's book on electrodynamics and i m stuck with probably one of the basic concepts on electric field. i did not understand what would be the electric field, 1) inside and 2)outside of a sphere with radius R ?

also there are two problems which deals with spheres, the first one be prob 2.8 says there should be some electric field inside but prob 2.15 says the total enclosed charge inside is zero, hence field zero. maybe i m not so clear on the idea of electric field, but on which context we can say the inside charge is zero or not.
someone plz make me clear on this.
regards

2. Mar 10, 2014

### Simon Bridge

Compare problem 2.8 with 2.15 - either there is a different method being used or there is some other important difference.

Note: zero total charge enclosed in a Gaussian surface does not mean zero field - it means there is net zero flux going through the surface. i.e. as many flux lines leave as enter.