Final answer:
The electric potential at a point with position vector r due to a point charge Q placed at the origin is given by the formula V = kQ/r. Electric potential is scalar and is added numerically for multiple charges, unlike the electric field which is a vector and requires vector addition.
Step-by-step explanation:
The electric potential at a point with position vector r due to a point charge Q placed at the origin is given by the formula V = kQ/r, where V represents the electric potential at the point, k is Coulomb's constant, Q represents the charge of the point charge, and r is the distance from the charge to the point where the electric potential is being calculated.
Electric potential is a scalar quantity and represents the potential energy per unit charge at a point in an electric field. The electric field, on the other hand, is a vector quantity and represents the force per unit charge. When calculating the total electric potential caused by multiple point charges, voltages from each charge are added as numbers. This is in contrast to electric fields from multiple charges, which must be added using vector addition to find the total electric field at a point.
It is important to note that for points outside a spherical charge distribution, such as a metal sphere, the electric potential behaves as if all the charge were concentrated at a point. This is why the concept of electric potential of a point charge is so fundamental in electrical physics, as it also applies to larger objects with spherical symmetry.