Question

A charge p is placed at the center of the line joining 2 equal charges q show that the system of the three charges wil bein

Answer 1

we can assume
p = q
and q = Q

Here,
OA = AB = x/2
OB = x
Force on the charge at B due to the charge at O is,
F1 = kQ^2 /x^2

Force on the charge at B due to the charge at A is,
F2 = kQq/(x/2)^2

For the system to be in equilibrium, F1 + F2 = 0
=> kQ^2 /x^2 + 4kQq/x^2 = 0
=> q = p = - Q/4


i hope it will help you
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