Electromagnetic Perpetuity?

Question

A current-carrying conductor placed in a magnetic field will produce a force in a direction perpendicular to the direction of the current and the field based on flux density x current ampere x length of conductor (in Newton).

My question is...

Doesn't that mean volt is not considered, which means we can use a transformer to decrease the voltage to increase the current (retain the watt) and thus produce more force, which also means we can feed back the increased force as input and produce perpetual motion? Please explain.

Answer 1

You can increase the current, but you can't feed it back in any useful way. Motion generates a counter-elecromotive force. In an electric generator, the rotor spins and creates a voltage, but the current drawn from it creates a field and consequent force opposing the driving force spinning the generator. Which is why you have to supply the turning force in the first place. There ain't no such thing as a free lunch.

Answer 2

You could imagine a generator producing electricity that powers a motor that turns the generator. In theory, that could go on forever; however, there are unavoidable losses in the process. Mainly there is finite resistance in the wires that dissipates energy and the system will slow down. Even if the wires were superconductors and didn't have resistance, the magnetic and electric fields will produce electromagnetic radiation which also takes away energy from the system. That part cannot be avoided.

Answer 3

No, because the work being done to move the current is reflected back into the primary. the work is reflected by the difficulty of moving the current in the primary by coupling of the difficulty to "push" out it's magnetic field, through the secondary windings. It's a direct coupled device,, there is no disconnect between the secondary and primary, the magnetic field is the coupler, therefore no way to feedback anything for free. there is no disconnect.