Bela Karlovitz used magneto-hydro-dynamic theory to invent one of these devices.
Bela Karlovitz used magneto-hydro-dynamic theory to invent one of these devices. Faraday invented consisting of a rotating flywheel. A type of these devices relies on conductive brushes rubbing against the conducting armature on a mechanical commutator. Magnetos are used for this purpose. A hollow metal globe in which static charges (*) accumulate due to friction is one of these devices. These devices in electrical circuits are usually either dynamos or alternators, depending on if the result is alternating or direct. For 10 points, name these devices, exemplified by an object named for van de Graaff, which create electrical currents.
Bela Karlovitz used magneto-hydro-dynamic theory to invent one of these devices.
electrical generators [or van de Graaff generators; prompt on dynamos; prompt on alternators]