Electric Force Calculation
Electric force between charges can be calculated using Coulomb's Law, which states that the force between two charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.

Force on Charge Q at the Center of Square
- The force on charge Q at the center of the square can be calculated by considering the individual forces between Q and each of the charges at the corners of the square.
- Since the charges at corners A and C are equidistant from Q, they will exert equal and opposite forces on Q, canceling each other out.
- Similarly, the charges at corners B and D will also exert equal and opposite forces on Q, canceling each other out.
- Therefore, the net force on charge Q at the center of the square will be zero due to the symmetrical arrangement of charges.

Explanation
- The forces between Q and the charges at the corners of the square will have components along the diagonals of the square.
- By symmetry, these components will cancel out each other, resulting in a net force of zero on charge Q.
- This can be understood by considering the vectors representing the individual forces and their cancellation due to the symmetry of the square.
- Therefore, the net force on charge Q at the center of the square will be zero, and Q will remain in equilibrium.
In conclusion, the net force on a charge Q placed at the center of a square with charges at its corners will be zero due to the symmetrical arrangement of charges. This can be understood by considering the individual forces between Q and the charges at the corners and their cancellation by symmetry.