Whatwould this magnetic field look like?

[avolaster]

a ring of iron wraped in a copper wire and the copper wire is fed electricity.

 

[berkeman]

a ring of iron wraped in a copper wire and the copper wire is fed electricity.

That's basically how transformers are made, but with separate windings. The magnetic field goes around inside the ring.

See the "Basic Principles" section here:

http://en.wikipedia.org/wiki/Transformer

.

 

[yungman]

You talking about an iron ring and INSULATED copper wire wrap around along the ring? That is like a toroid with wires and the magnet field going around in circle inside the ring.