" We will make electricity so cheap that only the rich will burn candles"
Thomas Edison

• Just as we calculated the electric field due to a dipole it is possible to calculate the electric potential.  However, in this case it is convenient to use polar co-ordinates. 

Assuming no azimuthal variation we may write,

When r >> a, then r₁, r₂ and r are approximately equal and r₂- r₁ = 2acosθ.  Therefore,

• Note that the dipole potential decreases as 1/r² whereas the dipole E field decreases as 1/r³ .

• Notice that when θ = 90⁰ V_P = 0, that is it would require no work to bring a charge from infinity to the center of the dipole if it moves along the dipole bisector.
  

"There are three kinds of men. The one that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves."
Will Rogers

 

Dr. C. L. Davis
Physics Department
University of Louisville
email: c.l.davis@louisville.edu