question_answer

Let \[\rho \left( r \right)=\frac{Q}{\pi {{R}^{4}}}r\] be the charge density distribution for a solid sphere of radius R and total charge Q. For a point ?P? inside the sphere at distance \[{{r}_{1}}\] from the center of the sphere, the magnitude of electric field is:

A) \[\frac{Q}{4\pi {{\in }_{0}}{{R}_{1}}^{2}}\]\[\]                      

B) \[\frac{Qr_{1}^{2}}{4\pi {{\in }_{0}}{{R}^{4}}}\]

C) \[\frac{Qr_{1}^{2}}{3\pi {{\in }_{0}}{{R}^{4}}}\]     

D)        \[0\]