What is the maximum speed fluctuation in a 3-phase synchronous motor____________?
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Answer: E. zero
Explanation
A synchronous motor maintains a strictly constant average speed with zero speed fluctuation. The rotor is magnetically locked to the rotating stator magnetic field during steady-state operation. Because slip is absolutely zero, rotational speed remains uniform without cyclic speed variations. Synchronous speed is tied directly to the constant frequency of the alternating current power grid. Transient load surges can cause momentary hunting, but steady-state speed fluctuation is nonexistent. This constant speed characteristic differentiates synchronous motors from all induction motor designs.
Precision industrial machinery and clocks require zero speed fluctuation to maintain accurate timing. Power generation facilities use synchronous drives to ensure absolute rotational stability across processes. Engineers value synchronous motors for applications demanding unwavering rotational velocity performance. Ten percent speed fluctuation describes poorly regulated DC or induction motor drives rather than synchronous. Six percent fluctuation is common in slip-ring induction motors under varying mechanical load torques. Four or two percent fluctuations occur in standard induction motors due to inherent slip characteristics.
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- Engineering
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- Electrical Engineering
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- —
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- medium
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Answer: B. rotor and the stator poles of opposite polarity
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Answer: B. pull-in torque
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Q4. The net armature voltage of a synchronous motor equals the_______________?
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Answer: D. vector difference of Eh and V
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Answer: A. zero
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