I am currently studying for a electrical engineering related exam and came across this problem.
What exactly is the difference between the nominal and idle RPM of a DC generator, and which one is higher?
To my understanding the nominal speed of the generator denotes the speed needed to match the power supply frequency (e.g. 50 Hz in Austria), if the generator is supposed to feed back into it.
When talking about a DC motor with shunt, I think understand the principle: Idle speed is reached when the rotor induces the same voltage in the stator as is applied to the rotor itself. Nominal speed is the RPM at which the motor delivers the nominal torque. Here, idle speed is higher than nominal speed.
Are those assumptions correct?