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Potential difference
Intermediate
Work per unit charge to move between points.
ΔV = −∫E·dlΔV = −∫E·dl is the work per unit charge to move between two points; it's the voltage. A charge q gains energy qΔV.
An electron accelerated through 100 V gains 100 eV.
The potential difference is independent of the path.
In more detail
Potential difference is the change in electric potential between two points, measured in volts. It equals the work done per unit charge to move a charge between them.
Real-world uses
- Mains electricity is a potential difference of about 230 volts.
- Measuring potential difference is the basis of voltmeters.
- A battery provides a potential difference that drives charges round a circuit, delivering energy to lamps and motors.
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Frequently asked questions
What is a volt?
One joule per coulomb.
Does potential difference depend on path?
No. The potential difference between two points is independent of path for static fields.
Why is the potential difference the work per charge?
It is the energy transferred for each coulomb moved between two points, which is what drives current.
Related topics in Electrostatics
Field of a conductor · Electrostatic shielding · Electric potential · Equipotential surfaces · Relation of E and V · Electron volt