Answer to Question #187662 in Engineering for Alock kumar

Question

Prove that synchronous speed, Ns=120f/p, where f is the line frequency and p is the no of poles.

Answer 1

$$\text{Cycles of current}=0.5p\text{ Revolutions of field}\\ f=0.5p\frac{N_s}{60}\\N_s=\frac{120f}{p}$$