Equipotential surface

Equipotential surfaces are surfaces of constant scalar potential. They are used to visualize an (n)-dimensional scalar potential function in (n-1) dimensional space. The gradient of the potential, denoting the direction of greatest increase, is perpendicular to the surface.

In fluid mechanics, equipotentials are lines or surfaces of equal head that are in direct relation to pressure. Streamlines are perpendicular to the equipotentials and are in the same direction that water is flowing.

The term is also used in electrostatics and geodesy.