A particle of mass \( m \) is suspended from a ceiling through a string of length \( L \). The particle moves in a horizontal circle of radius \( r \) such that \( r = \frac{L}{\sqrt{2}} \). The speed of particle will be:
$\sqrt{\frac{rg}{2}}$
\( \sqrt{rg} \)
\( 2\sqrt{rg} \)
\( \sqrt{2rg} \)