- #1
greypilgrim
- 513
- 36
Hi.
In order to explain the motion of an (accelerating) electromotor, we need the Lorentz force which itself is not one of Maxwell's equations.
Conversely, if we use the same electromotor inversely to generate electricity, Faraday's law (which is a Maxwell's equation) and the resistance of the circuit is enough to calculate the induced current, we don't need the Lorentz force law explicitely.
Those two processes look very symmetrical. But why do we need something beyond Maxwell's equations equation (namely the Lorentz force law) only when the device acts as motor? Or is the Lorentz force hidden somewhere (maybe in ##I=U/R## ?) when the device acts as a generator?
In order to explain the motion of an (accelerating) electromotor, we need the Lorentz force which itself is not one of Maxwell's equations.
Conversely, if we use the same electromotor inversely to generate electricity, Faraday's law (which is a Maxwell's equation) and the resistance of the circuit is enough to calculate the induced current, we don't need the Lorentz force law explicitely.
Those two processes look very symmetrical. But why do we need something beyond Maxwell's equations equation (namely the Lorentz force law) only when the device acts as motor? Or is the Lorentz force hidden somewhere (maybe in ##I=U/R## ?) when the device acts as a generator?