Question

A charge q is placed at the center of line joining twp equal charges Q . The system of three charges will be equilibrium if q is equal to
(1) +Q/2
(2) +Q/4
(3) -Q/2
(4) -Q/4
And elaborate your answer

Answer 1

Answer:

−Q/4

Explanation:

Let's see the force on one Q

F=kQ24a2+kqQa2

For the system to be in equilibrium F =0

kQ²/4a²+kqQ/a²=0

q=−Q/4