Electric Potential Energy

Definition

Electric potential energy is the potential energy possessed by an electric charge due to its position in an electric field. It is the work done by an external force in moving a charge from an infinite distance to a specific location within the electric field.

5 Must Know Facts For Your Next Test

1. The electric potential energy of a charge is directly proportional to the charge's magnitude and the electric potential at its location.
2. The electric potential energy of a system of charges is the sum of the potential energies of the individual charges.
3. The change in electric potential energy is equal to the work done by an external force in moving a charge within an electric field.
4. Electric potential energy is a scalar quantity, meaning it has magnitude but no direction.
5. The unit of electric potential energy is the joule (J), the same as the unit of work.

Review Questions

• Explain how the concept of electric potential energy relates to the behavior of capacitors in a circuit.
  • The electric potential energy stored in a capacitor is directly proportional to the capacitance of the capacitor and the square of the voltage across its terminals. As charges are stored on the capacitor's plates, the potential difference between the plates increases, resulting in an increase in the electric potential energy of the system. This stored energy can then be released to do work when the capacitor is discharged, making capacitors important components in electrical circuits.
• Describe how the electric potential energy of a charge changes as it moves within an electric field.
  • The electric potential energy of a charge is directly related to its position within an electric field. As the charge moves from a region of higher electric potential to a region of lower electric potential, its electric potential energy decreases. Conversely, if the charge moves from a region of lower electric potential to a region of higher electric potential, its electric potential energy increases. The change in electric potential energy is equal to the work done by the external force in moving the charge within the electric field.
• Analyze the relationship between electric potential energy, electric potential, and the concept of equipotential surfaces.
  • $$Electric\ Potential\ Energy = q \cdot V$$ where $q$ is the charge and $V$ is the electric potential. Equipotential surfaces are regions in an electric field where the electric potential has the same value. Since the electric potential is constant along an equipotential surface, the electric potential energy of a charge will also be constant as it moves along that surface. This means that no work is required to move a charge within an equipotential surface, as there is no change in the charge's electric potential energy.

Related terms

Electric Potential:

The electric potential is the amount of work done per unit charge in moving a test charge from infinity to a specific location within an electric field.

Equipotential Surfaces: Equipotential surfaces are imaginary surfaces where the electric potential has the same value. Charges on these surfaces experience no net force.

Capacitance:

Capacitance is the measure of the amount of electric charge a capacitor can store for a given electric potential difference across its terminals.