Answer to Question #184885 in Electric Circuits for Koali

Question

Why r indicates the distance from the point charge to the point at which the potential energy is evaluated from the given equation: U = k Σ q_i / r²_i ?

Answer 1

r indicates the distance from the point charge to the point at which the potential energy is evaluated from the given equation: $U=k\sum{\dfrac{q_i}{r_i}}$ because the electrostatic force between two charges is inversely proportional to the square of distance vector separating them and hence the potential experienced in the vicinity of the charge by other charge is inversely proportional to distance between them.