Physics

Physics

Problem

Which expression gives the change in electric energy ΔE\Delta E experienced by a point charge qq that moves through an electric potential difference ΔV\Delta V? a) 12 q ΔV\displaystyle \frac{1}{2}\,q\,\Delta V b) −q ΔV\displaystyle -q\,\Delta V c) q ΔV\displaystyle q\,\Delta V d) ∣q∣ ΔV\displaystyle |q|\,\Delta V
Intuitive explanation

The key insight is that electric potential is defined as energy per unit charge—it's the "work per charge" that the field does. When a charge moves through a potential difference, you simply multiply that per-charge energy by how much charge you have. Think of ΔV\Delta V as the energy cost (or gain) per coulomb, and qq as the number of coulombs; their product gives the total energy change.

Intuitive explanation

The key insight is that electric potential is defined as energy per unit charge—it's the "work per charge" that the field does. When a charge moves through a potential difference, you simply multiply that per-charge energy by how much charge you have. Think of ΔV\Delta V as the energy cost (or gain) per coulomb, and qq as the number of coulombs; their product gives the total energy change.

Browse the problem library