What is the required speed for an AC generator to reach a frequency of 40 Hz with 8 poles?

To determine the required speed for an AC generator to reach a specific frequency, one can use the relationship between frequency, number of poles, and speed, which is given by the formula:

[ \text{Frequency (Hz)} = \frac{\text{Speed (RPM)} \times \text{Number of Poles}}{120} ]

In this case, the desired frequency is 40 Hz, and the generator has 8 poles. By rearranging the formula to solve for speed, we find:

[ \text{Speed (RPM)} = \frac{\text{Frequency (Hz)} \times 120}{\text{Number of Poles}} ]

Substituting the known values:

[ \text{Speed (RPM)} = \frac{40 \times 120}{8} ]

Calculating this gives:

[ \text{Speed (RPM)} = \frac{4800}{8} = 600 ]

This would suggest a speed of 600 RPM. However, it seems the answer provided of 1200 RPM may stem from initially considering the synchronous speed at the incorrect interpretation of poles or was based on general formula misapplication.

Given the correct calculations directly linked to the requirement for 40 Hz