- #1
Old Guy
- 103
- 1
Homework Statement
Either Coulomb's Law or Gauss' Law and r>R, I get [tex]\textbf{E}=k\frac{Q}{r^{2}}\textbf{r}[/tex]. Q is the total charge. If R is the radius of the sphere, shouldn't the field at a point a<R simply be [tex]k\frac{Qa}{R^{3}}[/tex]? Inother words, the field is proportional to the enclosed charge, and the enclosed charge is proportional to the ratio of the radii cubed? Griffiths' answer is [tex]k\frac{Q}{R^{3}}\textbf{r}[/tex], i.e., there is no dependence on a. And it appears to be dimensionally inconsistent without a.