Why is a bendy? You can twist them into
all sorts of shapes.
Current-carrying wires generate magnetic
fields. So, if you combine these two, what
will happen? It can get complicated very
fast as you might imagine. So let's look
at a simple loop first. We found the
electric field around two charged
particles by looking at their light tube
food around individual particles and
then adding them together. We can apply
the same idea to the magnetic third
around the loop. While we look at the
magnetic field of each individual part
of the wire, and then add them together. I
can find the magnetic field around each
individual part of the wire with the
right-hand rule. So if I twist this wire
into a loop, and then rotate it. So one
side faces you and one side faces me. Now
let's say I had a cart in this wire
going towards me down the bottom up, up
the back towards you on top, and down the
front. Now, because the car goes towards
me down the bottom, the magnetic field is
clockwise, and up the top, the car goes
towards you, and the magnetic road is
anti-clockwise. You'll notice that my
fingers always point towards the right
on the inside of the loop, and it always
points towards the left on the outside
of the loop. This tells us that the
overall magnetic field because of the
route points to the right on the inside
of the loop and place the left on the
outside of the loop. Here's a 2D visual
representation of the magnetic field
around a loop. For the side on view that
we were just looking at the magnetic
field due to the bottom bit of the loop
would be circular in a clockwise
direction. The top bit of the loop would
also have a circular magnetic field.
However it will be anti-clockwise since
the current is traveling in opposite
directions. And as we've previously
discussed, the magnetic field will be
stronger in the middle due to all parts
of the car and reinforcing it, pointing
to the right. Around the outside, it will
be weaker, pointing to the left. So the
magnetic field around a loop looks like
this. You'll notice that this looks
similar to the magnetic field around a
bar magnet, except most-quash. 
If we like the ring flat and look at the
magnetic field from this perspective, we
get the bottom bit of the ring
generating a magnetic field going into
the page on the inside of the loop, and
out of the page outside of the loop. The
next bit of the ring would do the same
and so on. Overall, you would end up with
this field. With the field lines are
denser inside the ring and sparser
outside the ring.
