Electric potential, also known as voltage, is a measure of the potential energy per unit charge at a point in an electric field. It describes the amount of work that must be done to move a unit positive charge from infinity to that point against the electric field.
The electric potential at a point on a square is calculated using the formula V = k*q/r, where V is the electric potential, k is the Coulomb's constant, q is the charge of the point charge, and r is the distance from the point charge to the point on the square.
Electric potential and electric field are related by the equation E = -∇V, where E is the electric field, V is the electric potential, and ∇ is the gradient operator. This means that the electric field is the negative gradient of the electric potential.
The electric potential decreases as the distance from the point charge on a square increases. This follows the inverse square law, which states that the electric potential is inversely proportional to the distance squared.
The work done by an external force to bring a point charge from one point to another on a square is equal to the change in electric potential energy, which is calculated by multiplying the charge of the point charge by the difference in electric potential between the two points.