Three identical charged balls each of charge 2C are suspended from...

We have force between any two charge${F}_{1} = {F}_{2} = \dfrac{{q}^{2}}{4\pi{ε}_{0}{l}^{2}} = F$

Resultant electrostatics force ${F}_{R} = \sqrt{{F}_{1}^{2} + {F}_{2}^{2} + 2{F}_{1}{F}_{2}\cos 60 °}$

$= \sqrt{{F}^{2} + {F}^{2} + \left(2{F}^{2} \times \dfrac{1}{2}\right)} = \sqrt{3{F}^{2}}$

So, the ratio of net force on a charged ball to the force between any charged balls is

$⇒ \dfrac{{F}_{R}}{F} = \sqrt{3}$