\({E_{out}} = 100\frac{{KQ}}{{{{(20 \times {{10}^{ - 2}})}^2}}}\)
\(==> KQ = 100 \times (0.2)^2\) \({E_{in}} = \frac{{kqr}}{{{R^3}}}\)
\({E_{in}} = \frac{{100 \times {{(0.2)}^2} \times {{(3 \times {{10}^{ - 2}})}^2}}}{{{{(10 \times {{10}^{ - 2}})}^3}}}\)\(= 120\ V/m\)