Tiny rings made of magnetic material that can be polarised to represent binary 1 or 0 is called.
Tiny rings made of magnetic material that can be polarised to represent binary 1 or 0 is called Magnetic core.
A magnetic core is a piece of magnetic material with a high magnetic permeability used to confine and guide magnetic fields in electrical, electromechanical and magnetic devices such as electromagnets, transformers, electric motors, generators, inductors, magnetic recording heads, and magnetic assemblies.