The volume charge density of a sphere of radius 6m is 2μ C cm ^ - 3...

Given here, $ρ = 2\mu C{cm}^{- 3}$ and $R = 6m$.

Number of lines of force per unit area = electric field at surface$= \dfrac{KQ}{{R}^{2}}$

$E = \dfrac{1}{4\pi{ε}_{0}}\dfrac{ρ\dfrac{4}{3}\pi{R}^{3}}{{R}^{2}}$

$E = \dfrac{ρR}{3{ϵ}_{0}} = \dfrac{2 \times 6}{3 \times 8 . 85 \times {10}^{- 12}} = 0 . 45 \times {10}^{12}N{C}^{- 1}$

$= 45 \times {10}^{10}N{C}^{- 1}$