Final answer:
The electric potential at the center of the square due to all four charges is 4V₀, and the magnitude of the electric field at the center is 4E₀.
Step-by-step explanation:
To find the electric potential and magnitude of the electric field at the center of the square due to all four charges, we can use the principle of superposition. The electric potential at the center of the square is the sum of the electric potentials due to each individual charge. In this case, since all four charges are at the corners of the square, the electric potential at the center due to one charge alone, V₀, is the same for all charges. Therefore, the total electric potential at the center is 4V₀.
The magnitude of the electric field at the center of the square is also the sum of the electric fields due to each individual charge. Since all charges are positive and have the same magnitude, the electric fields will point away from the charges and towards the center of the square. The magnitude of the electric field due to one charge alone, E₀, is the same for all charges. Therefore, the total magnitude of the electric field at the center is 4E₀.