Answer :

9

Given, q1 = 1 μC, q2 = 10 μC

Let r₁ be the distance the two-point charges one placed placed at (0, 0, 0) and other at (0, 10 , 0)

r₁ = 10 m

Let r₂ be the final distance between the two-point charges one placed at origin (0, 0, 0) and other at (5, 0, 0)

r₂ = 5 m

Total work done in moving the pont charge from (0, 0, 0) to (5, 0, 0) is

$W=k{q}_1{q}_2(\frac{1}{r_2}-\frac{1}{r_1})$

$W=9\times {10}^9\times {10}^{-11}(\frac{1}{5}-\frac{1}{10})$

W = 9 mJ