Suppose a uniformly charged wall provides a uniform electric field of $$2 \times 10^4 \text{ N C}^{-1}$$ normally. A charged particle of mass 2 g being suspended through a silk thread of length 20 cm and remain stayed at a distance of 10 cm from the wall. Then the charge on the particle will be $$\frac{1}{\sqrt{x}} \mu C$$ where $$x$$ = ______ [use $$g = 10 \text{ m s}^{-2}$$]