Electric field intensity and electric potential
The electric field intensity at a point can be defined as the negative of the potential gradient at
that point. i.e.
Electric field intensity = - Potential gradient E = – dV/dx
Notice the negative sign - this implies that measuring from the positive plate the potential drops
with increasing distance.
In the uniform field the electric field intensity is the same anywhere in the field (hence the name)
and therefore you should see that the potential decreases steadily with distance from one plate
to the other. [dV = -Edx]
However in a radial field E is not constant and is then truly the gradient of the potential-distance
curve at any point.
Graph of potential gradient and electric field intensity for a radial field
WORD VERSION AVAILABLE ON THE SCHOOLPHYSICS CD
