Calculate the electric field at the centre of a cube, if seven of its corners are given a charge of 0.02 `mu`C and side of cube is 10 mm.

Explanation

To calculate the electric field at the center of a cube with seven of its corners charged with 0.02 µC, we can follow these steps:

### Step 1: Understand the Geometry of the Cube
The cube has 8 corners, and we are given that 7 of these corners have a charge of 0.02 µC. The side length of the cube is 10 mm.

### Step 2: Identify the Charges and Their Arrangement
Since 7 corners are charged, we can denote the charges at the corners as follows:
- Let the corners with charges be A, B, C, D, E, F, and G (7 corners).
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