https://blogs.imperial.ac.uk/videoarc...
Professor Eric Laithwaite (1921-1997) of Imperial College London demonstrates the difference between magnetic and electro-magnetic motors. Examples futuristic - include minute pump that can fit inside human tissue and a huge test rig to help develop high speed vehicles driven by a linear motor.

This is one of a series of 16mm colour films made for schools. They were all made in Eric Laithwaite's "Heavy Electrical Laboratory" in the Electrical Engineering Department at Imperial College London.