What is the principal of motor and what is prime mover?

What is the principal of motor

What is the prime mover?

Motors operate by inducing a magnetic field around an area which acts on another magnent causing it to spin. Either the field fluctuates around the magnent (Brushless) or there are contacts which supply the coil within a magnetic field to be moved.

Unless you are speaking about some philosophical principle, the prime mover would be the thing which moves first. The tractor pulls the traiiler, the locomotive pulls the train, the motor/turbine spins the generator. Both move synchronously but the prime one is usually the one supplying the power.