Two Equal Point Charges

The potential at point P is calculated by adding together the potentials due to both charges.

(13)

According to equation (7), the corresponding electric field is

(14)

The equipotential lines and the electric field vectors are sketched below for separation distance 2a = 1 m.

{sketch}

Please note that the lengths of the arrows in this plot are not exactly to scale. The reason for this is that a rescaling of the vectors had to be performed to get useful field information out of this graph.


If you were to plot this potential function in three-dimensional space such that the potential V(x,y) was plotted on the z-axis, what would be the resulting shape?

Answer

Now go on to get an intuitive feel for two point charges, using our charge applet.


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