How to graph equipotential lines of two charges?

by rslewis96
Tags: charges, equipotential, graph, lines
rslewis96 is offline
Nov30-13, 04:23 PM
P: 5
The two charges are (-q) and q. I'm just curious as to how you go about graphing them.

Phys.Org News Partner Physics news on
The hemihelix: Scientists discover a new shape using rubber bands (w/ video)
Mapping the road to quantum gravity
Chameleon crystals could enable active camouflage (w/ video)
GregoryS is offline
Nov30-13, 04:57 PM
P: 11
You have a dipole, which field you want to graph.
rslewis96 is offline
Dec1-13, 11:09 AM
P: 5
Quote Quote by GregoryS View Post
You have a dipole, which field you want to graph.
When you say field are you talking about the electric field lines? I know that when you draw the electric field lines that the equipotential lines are perpendicular to them. I'm lost as how to draw the electric field lines. I've been looking through my book and online, but can't find a way to draw them given that you have a dipole.

jtbell is offline
Dec1-13, 12:03 PM
jtbell's Avatar
P: 11,255

How to graph equipotential lines of two charges?

To get an approximate graph by hand:

1. Calculate the total electric field (from both charges, as a vector sum, with magnitude and direction) at many points, e.g. on a grid that covers the region around the charges.

2. At each point, draw an arrow that points in the direction of the field at that point.

3. By inspection ("eyeballing") you should be able to draw a set of lines that run from one charge to another (if the total charge is zero) or from one charge to infinity (if the total charge is not zero), and curve in such a way as to run more or less parallel to nearby arrows. These are field lines.

4. Draw a set of lines that always intersect the field lines perpendicularly. These are equipotential lines.

This should work, in principle, for any number of charges of any strength.

Register to reply

Related Discussions
equipotential lines and electric field lines Introductory Physics Homework 1
equipotential lines and electric field lines Advanced Physics Homework 1
Equipotential lines for two charges General Physics 3
Understanding Equipotential Lines and their relationship with Electric Field Lines General Physics 3
Drawing Electric Field Lines and Equipotential Lines Introductory Physics Homework 6