Question

Two negative and equal charges a and b are fixed at a certain distance d.third charge may be equilibrium at a position.​

Answer 1

Explanation:

At the middle of the distance between them

Answer 2

The third charge can be at the midpoint of the two negative charges.

Let the two negative charges = -q

Distance between the charges = d

Let the third charge = q'

q' is at distance a from one charge and (d-a) from the other charge .

At equilibrium -

- Kqq'/a = - kqq'/(d-a)

=> d-a = a

=> d = 2a

=> a = d/2

The third charge is at a distance d/2 from both the charges i.e , the third charge is at the midpoint of the two charges .