Question

Three identical charged balls each of charge $2$ $C$ are suspended from a common point $P$ by silk threads of $2$ $m$ each (as shown in figure). They form an equilateral triangle of side $1$ $m$. The ratio of net force on a charged ball to the force between any two charged balls will be:

• A. $1:1$
• B. $1:4$
• C. $\sqrt3:2$
• D. $\sqrt3:1$

Answer 1

Answer: (D)

$\sqrt3:1$

Answer 2

Force between any two charged balls will be:

$F_{net}$ on charge $3$,

$F_1=\frac{\sqrt3kq^2}{1 ^2}$

Force between any $2$ charges

$F_2=\frac{kq^2}{1 ^2}$

So,

$\frac{F_1}{F_2}=\sqrt3$

Hence, the correct option is (D): $\sqrt 3 : 1$