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In which of the following motor, the stator and rotor magnetic field rotates at the same speed w.r.t. Sator?
Universal motor
Synchronous motor
Induction motor
Reluctance motor
Synchronous motor
The correct answer is B (Synchronous motor). In a synchronous motor, the magnetic field of the stator and rotor rotates at the same speed, which is synchronous with the supply frequency.
The correct answer is B (Synchronous motor). In a synchronous motor, the magnetic field of the stator and rotor rotates at the same speed, which is synchronous with the supply frequency.
NsтАЛ=P120fтАЛ тАФ Synchronous speed calculation
This occurs because the rotor is designed to lock in with the rotating magnetic field created by the stator. The synchronous speed NsтАЛ is determined by the supply frequency f and the number of poles P in the motor, given by the formula NsтАЛ=P120fтАЛ.
In a synchronous motor, the rotor runs at synchronous speed without slip.
Synchronous motors are primarily used where precise speed is required.
Constant speed operation regardless of load variations.
Higher efficiency compared to induction motors.
Requires additional starting mechanisms.
More complex construction than induction motors.
Used in applications requiring high precision such as clocks and timers.
Often utilized in power generation systems.
Standard synchronous speed is dependent on the applied frequency.
Option A (Universal motor) works on a different principle and has variable speed based on load; Option C (Induction motor) has slip and does not run in synchronism with the field; Option D (Reluctance motor) does not maintain synchronous speeds under varying loads.
B is correct тАФ the stator and rotor magnetic fields rotate at the same speed in a synchronous motor.
Always remember the importance of synchronous speed for applications where precise motor control is essential.