Which scenario best illustrates electric potential energy?

Which scenario best illustrates electric potential energy?

• A. A positively charged pendulum suspended on a string over a negatively charged floor
• B. A light bulb connected to a battery
• C. A magnet sitting near a metal plate
• D. An electron flowing through a conductor

Answer: (A)

Electric potential energy is energy stored because of a system’s configuration in an electric field, specifically due to the positions of charges relative to one another. When opposite charges are brought near each other, the electric field stores energy that depends on how far apart they are. In this scenario, a positively charged pendulum sits near a negatively charged floor. The opposite charges attract, so the pendulum is placed in a position where the electric field is actively storing energy. If the pendulum moves closer, the energy changes—generally becoming more negative—while moving away increases the stored energy again. This dependence on position means the system contains electric potential energy that can be converted to kinetic energy as the pendulum swings. The other situations involve energy being used or transferred (a light bulb drawing energy from a battery) or involve magnetic effects or current flow, which aren’t about storing energy in the electric field due to the relative positions of charges.

Electric potential energy is energy stored because of a system’s configuration in an electric field, specifically due to the positions of charges relative to one another. When opposite charges are brought near each other, the electric field stores energy that depends on how far apart they are.

In this scenario, a positively charged pendulum sits near a negatively charged floor. The opposite charges attract, so the pendulum is placed in a position where the electric field is actively storing energy. If the pendulum moves closer, the energy changes—generally becoming more negative—while moving away increases the stored energy again. This dependence on position means the system contains electric potential energy that can be converted to kinetic energy as the pendulum swings.

The other situations involve energy being used or transferred (a light bulb drawing energy from a battery) or involve magnetic effects or current flow, which aren’t about storing energy in the electric field due to the relative positions of charges.