Two fixed point charges `+4e` and `+e` units are separated by a distance a. Where should a third point charge be placed for it to be in equilibrium?

Explanation

To find the position where a third charge should be placed for it to be in equilibrium between two fixed point charges \( +4e \) and \( +e \) separated by a distance \( a \), we can follow these steps:

### Step 1: Understand the Setup
We have two fixed charges:
- Charge \( Q_1 = +4e \) located at point A.
- Charge \( Q_2 = +e \) located at point B, such that the distance \( AB = a \).

We need to find the position of a third charge \( Q_3 \) (let's say \( Q_3 = q \)) such that the net force acting on it due to \( Q_1 \) and \( Q_2 \) is zero.
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