SSE JE Electrical Engineering 24 March 2021 Shift 1 Paper

The synchronous speed is the speed of the revolution of the magnetic field in the stator winding of the motor. It is the speed at which the electromotive force is produced by the alternating machine.
The Synchronous Speed $\left({\mathrm{N}}_{\mathrm{s}}\right)$ is given by
${\mathrm{N}}_{\mathrm{s}}=\frac{120\mathrm{f}}{\mathrm{P}}$
Where,
$\mathrm{f}$ is the frequency in Hz and P is the number of poles
P = 6
f = 60 Hz
Since, synchronous motor running at synchronous speed, therefore running speed of the synchronous motor is given by,
${\mathrm{N}}_{\mathrm{s}}=\frac{120\times 60}{6}=1200\mathrm{rpm}$