The change in electric potential, ∆V, is defined as this ratio.
It’s Potentially Important
The potential of a single
point in space is relatively
meaningless; instead, you
want to find the potential
difference between an
initial and final position.
As with gravity, it’s the
relation to another point
that matters, and moving
a charge from one point of
electrical potential
to another is what generates
energy. This is a
key concept for the next
chapter’s discussion of
electrical circuits.Electric potential is electrical potential energy per unit charge; the units of electric
potential are joules per coulomb. One joule per coulomb is called one volt
(abbreviated V); so = 1 V.
Consider the electric field that’s created by a point source charge Q. The electric
potential at a distance r from Q is
Notice that the potential depends on the source charge making the field and the
distance from it.