Discuss any inventions in history which are related to magnetism by referring to faraday disc?

Faraday invented the electromagnetic rotation.

Explanation:

Faraday invented a device called electromagnetic rotation, Faraday got a rotation with magnetic force, he used a cable, mercury, and a magnet.

The cable would rotate around the magnet, this would be a beginning for the electromagnetic technology.

For example:

The Homopolar motor or called electric motor was created for Faraday's invention.

We can find electric motor in Washing machines, fans, turbines, even in motorcycles and electric cars.

t = 1/400 h   ⇔ 0.0025 h ⇔ 9s ⇔ 0.15 m

any of the answers are correct.