Two point electric charges of unknown magnitudes and signs are placed a certain distance apart. The electric field intensity is zero at a point not between the charges but on the line joining them. Write two essential conditions for this to happen.

Explanation

To determine the conditions under which the electric field intensity is zero at a point not between two point charges but on the line joining them, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Configuration**:
- We have two point charges, \( Q_1 \) and \( Q_2 \), separated by a distance \( A \). The electric field intensity is zero at a point on the line joining them, but not between the charges.

2. **Identifying Possible Locations**:
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