Say an electric motor is connected via a switch to a battery. What would a graph to show how current varies with time look like (from when the switch is first closed).
I understand that when the switch is closed, initially the current increases rapidly because the motor just acts as a resistor. However, as the motor spins the flux linkage through the motor's coil changes.
When parallel to field lines the rate of change of flux linkage is at a max + when perp. the rate of change is zero. Hence, shouldn't the back emf (and therefore current) vary as the motor spins causing the current to vary continuously? - not tend towards a single value as suggested by the first graph
Any explanation would be greatly appreciated but I'm only doing A level physics so please keep as simple as possible!