Dear Faldage: the starter motor has a clutch that has to be engaged to crank engine, and solenoid moves one of the disks, I guess. Too bad Geoff isn't here, as an auto mechanic he would really know how to describe it. Washing machines also use one when going from wash to spin. I can't think of any devices that move core to affect current flow. A lot of things that used to use solenoids for light loads now use servo motors regulated by transistor circuits.
Wonderful to have the board so much more active, and windows change so quickly. Bill