Two small balls,each having mass $m$ and charge $q$,are suspended from a common point by insulating strings of length $L$ as shown in the figure. Assuming $\theta$ is very small such that $\tan \theta \approx \sin \theta$,find the value of $x$ at equilibrium.

• A
  ${\left( {\frac{{{q^2}L}}{{2\pi {\varepsilon _0}mg}}} \right)^{\frac{1}{3}}}$
• B
  ${\left( {\frac{{q{L^2}}}{{2\pi {\varepsilon _0}mg}}} \right)^{\frac{1}{3}}}$
• C
  ${\left( {\frac{{{q^2}{L^2}}}{{4\pi {\varepsilon _0}mg}}} \right)^{\frac{1}{3}}}$
• D
  ${\left( {\frac{{{q^2}L}}{{4\pi {\varepsilon _0}mg}}} \right)^{\frac{1}{3}}}$