Okay, I was wondering what you meant by "AC".
You mean Alternating Current.
A changing magnetic field generates an electric
field, and vice-versa. The polarity of the
magnetic field (which has field lines), and the
change in that polarity, determine the
corresponding direction of the electric field
lines. These electric field lines are what drive
the current in your wire.
In an AC generator, you have a magnet that is
swinging around in a circle, thus producing a
cycling magnetic field. The fact that the magnetic
field is changing one way, and then starts
changing the other way on the other side of the
cycle to get back to where it was, means that the
electric field is doing the same thing:
alternating. Thus, the electrical current must
alternate along with the electric field.
“Does voltage exist between the two terminals?”
Voltage exists but it is alternating along with
the alternating of the field. A static magnetic
field generates no electric field and thus no
current. It is only because the magnetic field is
alternating that there is any current at all.
You also don't need terminals. A loop of wire
with a magnet swinging through the loop will have
current flowing through the loop in a direction
determined by the movement of the magnet. This is
actually how an AC generator works: you need a
loop or otherwise the electric charge will get
stuck on one side like a capacitor.
“That potential difference in the generator is
between the two sides of the coil, but how is this
It's more that the potential is moving in a
circle - and then goes the other way when the
“My understanding of potential difference tells
me that for there to be a difference in potential
there has to be un-even amount of electrons
between two points, where one point possesses too
many, and the other possessing too little, thus
there is a potential difference between the two,
in which the electrons will desire to travel from
the higher potential to the lower potential
Yeah, like I said, what you're thinking about
is direct current, i.e. DC. In DC, you have a
potential difference that goes in one direction,
and current that flows in that direction. In AC,
the direction of the potential alternates, as does
the current, hence the name. The force responsible
for the current requires that the electricity be
flowing in a loop, not from a start point to a
destination. Without a loop, you will, as you say,
get all of the electrons on one side, which means
that you'll quickly run out of juice as the field
created by the electrons themselves will overpower
the electromagnetic process that makes AC work.
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