A hydraulic turbine having a rated speed of 250 rpm is connected to a synchronous generator. In order to produce power at 50 Hz, the number of poles required in the generator are
- A. 6
- B. 12
- C. 16
- D. 24
Answer: D. 24
Explanation: Synchronous speed Ns = 120f / P, so P = 120 × 50 / 250 = 24 poles.