Name for points where electric field lines meet at right angles

[morangta]

Homework Statement

I'm looking at an electric field plot around four (4) + and - point charges in free space.
There are several points where the electric fields come together and make right-angled turns (in the limit). Is there a name for these points? Especially is there a traditional name for these points? Thanks for reading.

Homework Equations

The Attempt at a Solution

 

[berkeman]

Homework Statement

I'm looking at an electric field plot around four (4) + and - point charges in free space.
There are several points where the electric fields come together and make right-angled turns (in the limit). Is there a name for these points? Especially is there a traditional name for these points? Thanks for reading.

Homework Equations

The Attempt at a Solution

Can you post a picture or drawing? Or a link to a source of such a diagram? That would help a lot.