I asked the following question to my teacher through email a week ago, and he hasn't replied.(adsbygoogle = window.adsbygoogle || []).push({});

Consider a uniformly charged spherical shell of radius R and areal density [itex]\sigma[/itex] and consider also a cartesian system whose origin coincide with the center of the shell.

Clearly if we attempt to calculate the field at r = R directly through Coulomb's law, we obtain that the field is undefined, because we'd have a (r' - r') at the denominator (equ. 2.7 in Griffiths)

But, as Griffiths remarks (pp.88), if we apply Gauss' Law, we obtain that the field at r = R is of magnitude [itex]\sigma \epsilon_0[/itex]. So what should we think? Is the sclalar function E(r) undefined at r = R or not ?!

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Gauss again

**Physics Forums | Science Articles, Homework Help, Discussion**