equipotential diagram

[jimmy_neutron]

Im having trouble reading this diagram. I know that the difference between each equipotential line is .2mV

http://i51.photobucket.com/albums/f382/physicshelp/dba1a478.jpg

The question asks for the potentials at point A and point B, how the slope of the potential surface at point X is related to the spacing between the equipotential contours at point X, and the magnitude of the electric field at point X. I am kind of lost on how to read the diagram.

Any insights or help would be greatly appreciated. Thanks!

[finchie_88]

At point A, I think that the electric field strength is 0.6 mV, since there is a spacing of 0.2 mV, and there are three "lines" between it and 0 mV. The electric field strength at B is -0.2 mV, for a similar reason.

[jimmy_neutron]

OK i see that now. As for the electric field of X, i know that the electric field is equal to Force / Charge but I dont know how to get those variables from the diagram. Any help would be great. thanks.