A point charge is located at the center of a thin spherical conducting shell of inner and outer radii r$1$ and r$2,$ respectively. A second thin spherical conducting shell of inner and outer radii R$1$ and R$2,$ respectively, is concentric with the first shell. The flux is as follows for the different regions of this arrangement.

$\backslash$Phi $=14\mathrm{.}310^3$ N $$ m$^2/$C for r $<$ r$1$

$\backslash$Phi $=0$ for r$1<$ r $<$ r$2$

$\backslash$Phi $=21\mathrm{.}910^3$ N $$ m$^2/$C for r$2<$ r $<$ R$1$

$\backslash$Phi $=0$ for R$1<$ r $<$ R$2$

$\backslash$Phi $=21\mathrm{.}910^3$ N $$ m$^2/$C for r $>$ R$2$

Determine the magnitude and sign of the point charge and the charge on the surface of the two shells.

point charge $$C

inner shell $$C

outer shell $$C