# Please explain equipotential surfaces/ contour maps

## Homework Statement

Can someone please define contour map for equipotential surfaces in really simple terms.
I understand that the potential diff is from the neg side
I dont understand what it means when the lines are closer together?
I thought the lines are just divisions of the voltage, and an equipotential surface means that the potential anywhere along each individual line is uniform, but it is different from line to line (cuz your moving further or closer to the negative)

Please help!

## Homework Equations

an example:

// / / / / / / /

if this is contour map, what do the close-together lines mean??

## Answers and Replies

Ouabache
Science Advisor
Homework Helper
An analogy is a contour map for elevation (topographical). The closer spaced lines indicate the elevation changing more rapidly (example: hill or ravine). With equipotential surfaces, closer spaced lines indicate that potential (voltage), is changing more rapidly over distance. Here is an http://www.britannica.com/eb/art-1327/Equipotential-surfaces [Broken]

Last edited by a moderator:
Ok thanks, that helps, but now i guess im having prob with the actual word.
"EQUI" .... --what exactlly is equal in the contour map? i am assuming equi word root means "equal"

DaveC426913
Gold Member
All points along any given line have equal potential.

Just like on a map, all points on any line have equal altitude.