Three charges, each equal to q, are placed at the three. corners of a square of side a . Find the electric field at. the fourth corner.

Explanation

To find the electric field at the fourth corner of a square where three charges are placed at three corners, we can follow these steps:

### Step 1: Understand the Configuration
We have three charges, each equal to \( q \), placed at three corners of a square with side length \( a \). We need to find the electric field at the fourth corner (let's call it point D).

### Step 2: Determine the Electric Field Due to Each Charge
1. **Electric Field due to Charge at Corner A (E1)**:
- The charge at corner A creates an electric field at point D directed away from A (since the charge is positive).
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