Why outlets spark when unplugging - EMF & Inductors

Does it have to be an inductor?  What if you had just a long length of wire, not wound upon a spool?  In your water pipe example you describe the water hammer effect which makes sense because water is moving through a pipe.  What if you just had a long length of wire and pulled the handle up?  Would it still spark as violently?  Take the same amount of wire that is wound in that inductor and lay it flat, for example.