A series of interactive models illustrating the origin of the idea of the rotating magnetic field has also been exhibited: rotation of a copper plate by induced currents, the experiment of Arago from 1825, then the Baily motor with commutated direct currents and static electromagnets (1879) and Tesla two-phase generator together with the models of synchronous and asynchronous motor operated by two-phase alternate currents.

The hydraulic analogy, made according to an idea of Tesla, acquaints visitors with his conception of the physical principles of the rotating magnetic field visually demonstrating the vectorial addition of two identical sine curves, perpendicular to each other, with the phase difference of 90o.

In 1893, at the World Exhibition in Chicago, Tesla had presented his witty model of the induction motor with egg-shaped rotor. This model, together with the working model of the first "genuine" induction motor with short-circuit rotor, depicts the most important part of the Tesla polyphase system.

The patents of Nikola Tesla laid the foundation for the construction of new generators of polyphase currents. It has also been witnessed by the plaque of one of the generators of the hydro-power plant at Niagara Falls (1899), placed next to the model of the hydro-energetic system. The date of bringing the first generators in this power plant into service marks the date of the beginning of electrification of the world. The small-scale model of the hydro-energetic system with three-phase currents placed in this room demonstrates all the essential elements of this invention of Nikola Tesla.

The story about Tesla's inventions is continued with the paddle-less turbine, pump and speed indicator constructed 1913 - 1916 on the same principle. Tesla had occupied himself more than twenty years trying to improve them, and it was not until the end of 20th century that these inventions began attracting attention and comprehension among scientists and engineers.