How many cycles are produced by a 20-pole alternator rotor in making one revolution?

How many cycles are produced by a 20-pole alternator rotor in making one revolution?

• A. 5 cycles
• B. 10 cycles
• C. 20 cycles
• D. 40 cycles

Answer: (B)

The number of electrical cycles generated in one turn depends on how many poles the rotor has. Each pole pair (one north and one south) produces one complete electrical cycle as the rotor makes a full revolution. So cycles per revolution equal the number of pole pairs, which is half the total number of poles. With twenty poles, there are ten pole pairs, so ten electrical cycles are produced during one rotor revolution. In general, cycles per revolution = poles ÷ 2. This also connects to the frequency formula f = (P × N)/120, showing how pole count drives cycle count per mechanical turn. Ten cycles per revolution.

The number of electrical cycles generated in one turn depends on how many poles the rotor has. Each pole pair (one north and one south) produces one complete electrical cycle as the rotor makes a full revolution. So cycles per revolution equal the number of pole pairs, which is half the total number of poles.

With twenty poles, there are ten pole pairs, so ten electrical cycles are produced during one rotor revolution. In general, cycles per revolution = poles ÷ 2. This also connects to the frequency formula f = (P × N)/120, showing how pole count drives cycle count per mechanical turn. Ten cycles per revolution.