Potential difference

Definition

Potential difference is the work done to move a unit charge between two points in an electric field. It is measured in volts (V) and often referred to as voltage.

5 Must Know Facts For Your Next Test

1. Potential difference drives the flow of electrons in a circuit, creating electric current.
2. It can be calculated using Ohm’s Law: $V = IR$, where $V$ is potential difference, $I$ is current, and $R$ is resistance.
3. In a uniform electric field, potential difference can be expressed as $V = Ed$, where $E$ is the electric field strength and $d$ is the distance between two points.
4. Batteries provide a constant potential difference known as electromotive force (EMF), though terminal voltage may vary under load.
5. The unit of potential difference, the volt (V), is equivalent to one joule per coulomb ($1\text{ V} = 1\text{ J/C}$).

Review Questions

• What is the relationship between potential difference, current, and resistance in Ohm's Law?
• How does potential difference relate to the concept of electric potential energy?
• Explain how a battery maintains a constant potential difference across its terminals.

Related terms

Electric Field: A region around charged particles or objects within which other charged particles experience a force.

Electromotive Force (EMF): The energy provided per coulomb of charge by an energy source such as a battery or generator.

Terminal Voltage: The actual voltage output of a battery or power source when it is connected to an external circuit.