How is the Magnetic Field Shaped in a Hollow Cylinder Electromagnet?

[ƒ(x)]

Ok, everyone knows what an electromagnet is--the most obvious example being wire coils around a nail through which a charge is passed. If you had a hollow cylinder, and the coils were wrapped around the outside; how would the magnetic field be shaped?

Illustration (Please assume that there are more coils than shown and that the right side of the cylinder is not slanted.):

|--> |
|---> |
|----> |

 

[Defennder]

You have what is known as a solenoid. You can easily find B-flux lines for this configuration in most physics or electromagnetics textbooks.

 

[ƒ(x)]

Thanks, I have one right in front of me. Is there any difference in the fields of a solenoid and a hollow one?