How many cycles are produced by a 2-pole rotor in one full revolution?

How many cycles are produced by a 2-pole rotor in one full revolution?

• A. 0
• B. 1
• C. 2
• D. 4

Answer: (B)

Electrical cycles per mechanical revolution are determined by how many magnetic pole pairs the rotor has. Each pole pair creates one complete electrical cycle as the rotor turns through 360 degrees. A two-pole rotor has one north–south pole pair, so a full 360-degree turn brings the stator coil through one full cycle of magnetic polarity change—from positive to negative back to positive. Therefore, one full revolution yields one electrical cycle. If there were more poles, you’d get more cycles per revolution: cycles per revolution equals the number of poles divided by two.

Electrical cycles per mechanical revolution are determined by how many magnetic pole pairs the rotor has. Each pole pair creates one complete electrical cycle as the rotor turns through 360 degrees. A two-pole rotor has one north–south pole pair, so a full 360-degree turn brings the stator coil through one full cycle of magnetic polarity change—from positive to negative back to positive. Therefore, one full revolution yields one electrical cycle. If there were more poles, you’d get more cycles per revolution: cycles per revolution equals the number of poles divided by two.