how does the magnitude of the electrical change of objects affect the electric force between them

The magnitude of the electrical charge of objects affects the electric force between them according to Coulomb's law. This law states that the electric force between two objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. Therefore, if the magnitude of the electrical charge of one or both of the objects is increased, the electric force between them will also increase.