A four-pole generator completes one revolution. How many cycles are produced?

A four-pole generator completes one revolution. How many cycles are produced?

• A. One
• B. Two
• C. Zero
• D. Three

Answer: (B)

The number of electrical cycles produced per mechanical revolution equals the number of pole pairs on the machine. A four-pole machine has two pole pairs, so one complete turn of the rotor makes the magnetic field seen by the stator complete two full oscillations. In other words, one revolution yields two electrical cycles. This relationship is why the electrical frequency f is proportional to the number of pole pairs: f = (P/2) × (rpm/60).

The number of electrical cycles produced per mechanical revolution equals the number of pole pairs on the machine. A four-pole machine has two pole pairs, so one complete turn of the rotor makes the magnetic field seen by the stator complete two full oscillations. In other words, one revolution yields two electrical cycles. This relationship is why the electrical frequency f is proportional to the number of pole pairs: f = (P/2) × (rpm/60).