Tic
Motor tics are movement-based tics affecting discrete muscle groups.
Hovertrain
At about the same time, Eric Laithwaite was building the first practical linear induction motors (LIMs), which, prior to his efforts, had been limited to "toy" systems. A LIM can be built in several different ways, but in its simplest form it consists of an active portion on the vehicle corresponding to the windings on a conventional motor, and a metal plate on the tracks acting as the stator. When the windings are energized, the magnetic field they produce causes an opposite field to be induced in the plate. There is a short delay between field and induced field due to hysteresis.