What is the synchronous speed for a 2‑pole, 60 Hz motor?

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Multiple Choice

What is the synchronous speed for a 2‑pole, 60 Hz motor?

Explanation:
Synchronous speed is the speed at which the stator’s magnetic field rotates, and it depends on the supply frequency and the number of poles. The relation is Ns = 120 f / P, with Ns in rpm, f in Hz, and P the number of poles. For a 60 Hz supply and a 2-pole machine, Ns = 120 × 60 / 2 = 3600 rpm. This is the speed the rotor would lock to in theory; in a real induction motor the rotor runs slightly below this speed due to slip, but the synchronous speed here is 3600 rpm. The other values would correspond to more poles (e.g., 4 poles gives 1800 rpm, etc.), so 3600 rpm is the correct synchronous speed for this setup.

Synchronous speed is the speed at which the stator’s magnetic field rotates, and it depends on the supply frequency and the number of poles. The relation is Ns = 120 f / P, with Ns in rpm, f in Hz, and P the number of poles. For a 60 Hz supply and a 2-pole machine, Ns = 120 × 60 / 2 = 3600 rpm. This is the speed the rotor would lock to in theory; in a real induction motor the rotor runs slightly below this speed due to slip, but the synchronous speed here is 3600 rpm. The other values would correspond to more poles (e.g., 4 poles gives 1800 rpm, etc.), so 3600 rpm is the correct synchronous speed for this setup.

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