Correct Answer - Option 1 : 3600 rpm

__Concept:__

Synchronous speed of synchronous machine can be calculated as

\({N_s} = \frac{{120f}}{P}\)

Where,

f = Supply frequency in Hz

P = Number of poles

Ns = Synchronous speed in rpm

__Calculation:__

Given, f = 60 Hz

To get the maximum speed, the poles must be minimum.

Poles, P = 2

\(\therefore {N_s} = \frac{{120 \times 60}}{{2}}\)

NS = 3600 rpm