equipotential surface

Technically, an equipotential surface of the true geopotential, chosen to coincide (on average) with mean sea level.

It cuts at right angles every equipotential surface which it meets.

Some of these equipotential surfaces are shown in Fig. 2.2 with dotted lines.

Notice that the field lines are perpendicular to the equipotential surfaces.

Yes, you guessed correctly, we are going to investigate the equipotential surfaces and field lines of two point charges.

The equipotential surfaces are given by the equation, where k is a constant.

The geoid is a particular equipotential surface, and is somewhat involved to compute.

Furthermore, equipotential surfaces are always perpendicular to the net electric field lines passing through it.

Aquadag is not subject to such effects, and provides a completely uniform equipotential surface for electrostatics.

The two together can be described by a potential, so that, for example, the stellar surfaces lie along equipotential surfaces.