what is the speed of the rotor needed to generat 60 HZ in a

what is the speed of the rotor needed to generat 60 HZ in a synchronous generator. if the number of poles is 4 ?

Solution

speed of the rotor in a synchronous generator=synchronous speed=Ns=(120*f)/p

where f=frequency=60Hz

p=number of poles=4

therefore Ns=120*60/4=1800 RPM