Graphical variation of electric field due to a uniformly charged...

The electric field inside a solid insulated sphere is given by&

${E}_{inside} = \dfrac{ρr}{3{ε}_{0}}$ for $r < R$ where $ρ$ is& volume& charge density.

Hence,& the electric field varies linearly with the distance as

${E}_{inside} ∝ r^{1}$

Now, the electric field for $r > R$ is given by&

${E}_{outside} = \dfrac{Q}{4\pi{ε}_{0}r^{2}}$

${E}_{outside} ∝ \dfrac{1}{r2}$

Thus, the graph starts decreasing as a power law graph as shown in the figure for the region $r > R$.

Hence, this graph is the right option.