Correct Answer - Option 4 : 0
Synchronous speed in rpm is given by
\({N_s} = \frac{{120f}}{P}\)
Where f is supply frequency
P is the number of poles
Synchronous speed is dependent on the frequency and number of poles but not on the load torque.
Synchronous motor running at the constant synchronous speed. Therefore there is no speed loss, so the speed regulation of synchronous motor is zero.
